Comparative innate immune responses across major RNA and DNA viral infections: Mechanisms, immunopathology, and therapeutic perspectives

ABSTRACT

Innate immunity is the first defense against viral infections, limiting viral replication and initiating adaptive immunity. Viral pathogens are recognized by pattern recognition receptors (PRRs), including Toll-like receptors (TLRs), (RIG-I-like receptors) RLRs, and the (cyclic GMP-AMP synthase) cGAS-STING pathway, which trigger interferon production and antiviral responses. This review compares innate immune responses to major RNA viruses (influenza, SARS-CoV-2, HIV) and DNA viruses (HSV, HBV, CMV). While these viruses activate similar pathways, they differ in interferon dynamics, inflammatory responses, immune cell activation, and immune evasion mechanisms. RNA viruses often induce rapid and strong innate responses, whereas many DNA viruses establish persistence through immune modulation. Dysregulated innate immunity can contribute to cytokine storms, chronic inflammation, and tissue damage. Therapeutic strategies targeting innate immunity, such as interferons, cytokine inhibitors, PRR agonists, and host-directed antivirals, may improve outcomes. Infection severity depends on the timing, magnitude, and regulation of innate immune responses.

Introduction

Viral infections remain a major cause of global morbidity and mortality, posing persistent challenges to public health despite advances in antiviral therapies and vaccination strategies. Emerging and reemerging viruses, including influenza virus, SARS-CoV-2, HIV, and HSV, continue to exert substantial clinical and socioeconomic burden worldwide.^1,2 The clinical outcome of viral infection is largely determined by the efficiency and regulation of early host immune responses.

The innate immune system represents the first line of defense against viral invasion. Unlike adaptive immunity, which relies on antigen-specific recognition and clonal expansion, innate immunity provides rapid and evolutionarily conserved responses through germline-encoded PRRs. These include TLRs, RLRs, and cytosolic DNA sensors such as cGAS, which detect viral nucleic acids and activate downstream signaling cascades leading to interferon production and pro-inflammatory cytokine release.^3,4

Type I and type III interferons (IFNs) are central mediators of antiviral defense, inducing an antiviral state in infected and neighboring cells, while innate immune effector cells such as macrophages, dendritic cells, natural killer (NK) cells, and neutrophils contribute to viral clearance through cytokine secretion and cytotoxic functions.⁵ However, dysregulated or excessive innate immune activation may result in immunopathology, including cytokine storm syndromes observed in severe influenza and COVID-19.^6–8

Despite the shared use of core sensing pathways, viruses exhibit substantial diversity in their interactions with the innate immune system. Representative RNA viruses discussed in this review (including influenza virus, SARS-CoV-2, and HIV) generally trigger rapid interferon responses through RIG-I- and TLR-mediated signaling, whereas the representative DNA viruses examined (HSV, HBV, and CMV) employ diverse strategies to modulate cytosolic DNA sensing pathways. These features should not be considered universal across all RNA or DNA viruses. In addition, chronic viral infections such as HIV and HBV are characterized by persistent immune activation and progressive dysfunction of innate immune cells.

Although individual virus host interactions have been extensively studied, a comprehensive comparative analysis across major RNA and DNA viruses remains limited. Such comparative perspectives are essential for identifying conserved immune mechanisms as well as virus-specific immune evasion strategies, which may inform the development of broad-spectrum antiviral and immunomodulatory therapies.^9,10

Although RNA and DNA viruses activate overlapping innate immune sensing pathways, important differences exist in the timing and magnitude of interferon responses, inflammatory activation, and immune evasion strategies. These differences critically determine viral persistence, disease severity, and the outcome of therapeutic interventions targeting host immunity.

Accordingly, this review provides a structured comparative analysis of innate immune responses to major RNA and DNA viruses, focusing on (1) viral recognition by innate immune sensors, (2) downstream antiviral signaling pathways, (3) immune evasion mechanisms, and (4) emerging therapeutic strategies targeting innate immunity.

Because of the remarkable diversity within RNA and DNA virus families, the comparisons presented in this review are limited to representative medically important viruses and should not be interpreted as universally applicable to all RNA or DNA viruses.

Components of innate immunity against viruses

The innate immune system represents the earliest line of defense against viral infections, relying on an integrated network of physical barriers, germline-encoded sensors, soluble mediators, and specialized immune cells. These components act in a coordinated manner to detect viral invasion, restrict replication, and shape subsequent adaptive immune responses. Importantly, the magnitude and kinetics of these responses vary significantly depending on viral genome type and immune evasion strategies, which is a central theme of this review.^11,12 The major components and signaling pathways of innate antiviral immunity are summarized in Figure 1.

Figure 1.

Overview of innate immune responses against viral infections. Viral pathogens are recognized by PRRs, including TLRs, RLRs, and the cGAS-STING pathway. Activation of these signaling pathways induces interferon production, inflammatory cytokine release, and recruitment of innate immune cells such as macrophages, dendritic cells, neutrophils, and NK cells, leading to antiviral defense and immune regulation.

Physical and chemical barriers

Physical and chemical barriers constitute the first layer of defense against viral entry. The skin provides a structural barrier composed of tightly connected epithelial cells and keratinized layers that restrict pathogen penetration. Mucosal surfaces of the respiratory, gastrointestinal, and urogenital tracts represent major entry sites for viruses and provide specialized defense mechanisms.

These mucosal surfaces produce mucus rich in mucins, antimicrobial peptides (e.g., defensins and cathelicidins), and soluble factors that trap or inactivate viral particles. Mucus also facilitates mucociliary clearance, reducing viral load at epithelial surfaces.

Chemical factors such as low gastric pH, lysozyme, lactoferrin, and other secreted enzymes further contribute to viral inactivation. In the respiratory tract, surfactant proteins participate in both pathogen binding and immune modulation.

Importantly, epithelial cells are active participants in antiviral immunity. Upon infection, they produce IFN I and IFN III as well as cytokines and chemokines that recruit immune cells and establish a local antiviral state. However, many viruses bypass or exploit these barriers through receptor-specific entry mechanisms or microtrauma-associated infection.

For example, influenza virus binds sialic acid residues on respiratory epithelium, HIV targets mucosal immune cells during transmission, and HSV enters through disrupted epithelial surfaces. These differences illustrate that early barrier interactions are already shaped by virus-specific strategies.^3,4

PRRs

PRRs are central to viral detection through recognition of pathogen-associated molecular patterns (PAMPs), including viral RNA, DNA, and replication intermediates.^13,14

PRRs are expressed in immune and nonimmune cells such as macrophages, dendritic cells, fibroblasts, and epithelial cells. They include TLRs, RLRs, NOD-like receptors (NLRs), and cytosolic DNA sensors.

Endosomal TLRs (TLR3, TLR7/8, and TLR9) detect viral nucleic acids within intracellular compartments. TLR3 senses double-stranded RNA, while TLR7/8 recognize single-stranded RNA typical of RNA viruses such as influenza virus and SARS-CoV-2. TLR9 detects unmethylated CpG DNA motifs commonly associated with DNA viruses such as herpesviruses.^15,16

Cytosolic DNA sensing is primarily mediated by the cGAS-STING pathway, which detects viral DNA and induces type I interferon and inflammatory cytokine production. This pathway is particularly relevant for DNA viruses such as HSV.^17,18 Downstream signaling converges on transcription factors including IRF3, IRF7, and NF-κB, resulting in interferon and cytokine production.

However, a key comparative distinction across viruses is the degree of PRR antagonism. Many RNA viruses (e.g., SARS-CoV-2) suppress early interferon induction, whereas DNA viruses frequently encode proteins that directly inhibit DNA sensing pathways such as cGAS-STING, enabling persistence or latency. This difference is a major determinant of infection outcome.^19,20

Interferon and antiviral signaling

IFNs are central effector cytokines of innate antiviral immunity and mediate the establishment of an antiviral state through induction of interferon-stimulated genes (ISGs). IFNs are classified into type I (IFN-α/β), type II (IFN-γ), and type III (IFN-λ). Type I IFNs are broadly expressed and represent the primary antiviral response. Type III IFNs are particularly important at mucosal surfaces, whereas IFN II is mainly produced by NK and T cells and bridges innate and adaptive immunity.^21,22

PRR activation triggers signaling through adaptor molecules such as MAVS, TRIF, and STING, leading to activation of IRF3/IRF7 and NF-κB. Secreted IFNs bind to their receptors and activate the JAK-STAT pathway, inducing hundreds of ISGs such as PKR, OAS, and Mx proteins.^23–25

A key comparative feature across viral infections is the timing of IFN responses. Acute RNA viruses typically induce rapid and strong IFN responses, whereas viruses such as SARS-CoV-2 can delay IFN production during early infection.^26,27 In contrast, chronic viruses such as HIV and HBV are associated with prolonged but dysregulated IFN signaling, contributing to immune exhaustion and chronic inflammation.^28,29

Thus, not only the presence of IFN signaling but its timing and regulation critically influence disease outcome.

Innate immune cells

Innate immune cells coordinate early antiviral defense and shape downstream adaptive immunity. These include macrophages, dendritic cells, NK cells, and neutrophils, each contributing through distinct but interconnected mechanisms.^3,4

Macrophages

Macrophages are tissue-resident phagocytes that recognize viral components via PRRs and produce cytokines such as IL-6, TNF-α, and IFN I. They contribute to viral clearance and inflammation.³⁰ A key comparative aspect is their dual role in protection and pathology. While they limit viral spread, excessive activation particularly in RNA virus infections such as influenza and COVID-19 contributes to cytokine storm syndromes. In contrast, some viruses (e.g., HIV) exploit macrophages as reservoirs for persistent infection.^31–33

Dendritic cells (DCs)

DCs, especially plasmacytoid DCs (pDCs), are major producers of type I IFNs and act as a bridge between innate and adaptive immunity.^34,35

RNA viruses such as influenza strongly activate DC-mediated IFN responses, whereas in severe SARS-CoV-2 infection impaired DC function is associated with reduced antiviral signaling. Some viruses, including HIV, interfere with DC maturation and antigen presentation, facilitating immune escape.^12,36–38

NK cells

NK cells eliminate virus-infected cells through cytotoxic mechanisms involving perforin and granzymes. They also produce IFN-γ, enhancing macrophage activation.^6,39 NK cell activity is particularly important in infections with herpesviruses and CMV. Viral evasion strategies targeting NK cells are common, including MHC-I mimicry in CMV and NK dysfunction in chronic HIV infection.^40,41

Neutrophils

Neutrophils contribute to early antiviral defense through ROS production, cytokine secretion, and formation of neutrophil extracellular traps (NETs).⁷ In respiratory viral infections such as influenza and COVID-19, neutrophils are rapidly recruited. While protective at moderate levels, excessive neutrophil activation and NET formation contribute to tissue damage, thrombosis, and severe disease outcomes.^42,43 Elevated neutrophil activity is therefore more strongly associated with immunopathology than viral clearance in severe infections. The principal innate immune cells involved in antiviral defense and their major functions during viral infections are summarized in Table 1.

Table 1.

Major innate immune cells and their antiviral functions during viral infections.

Innate Immune Cell	Main Antiviral Functions	Major Cytokines/Molecules	Role in Viral Infection
Macrophages	Phagocytosis, cytokine secretion, antigen presentation	IL-6, TNF-α, IFN-I	Viral clearance and inflammation
Dendritic cells	Antigen presentation, interferon production	IFN-α, IFN-β	Activation of adaptive immunity
NK cells	Cytotoxic killing of infected cells	IFN-γ, perforin, granzymes	Early elimination of infected cells
Neutrophils	NET formation, inflammatory responses	ROS, NETs, proteases	Pathogen trapping and tissue inflammation
Epithelial cells	Barrier defense, interferon secretion	IFN-λ, chemokines	Early viral sensing and antiviral signaling
pDCs	Massive type I interferon production	IFN-I	Rapid antiviral response

Integrative perspective

Collectively, innate immune components function in a tightly coordinated network. However, a key theme emerging from comparative viral immunology is that disease outcome is not determined solely by activation of innate immunity, but by the timing, magnitude, and regulation of these responses, which vary significantly between RNA and DNA viruses and are actively shaped by viral immune evasion strategies.

Comparative innate immune responses in different viral infections

A central concept emerging from comparative viral immunology is that innate immune responses are not uniform across viral infections but are shaped by a dynamic interplay between viral genome type, replication strategy, and immune evasion capacity. Although RNA and DNA viruses engage overlapping PRR pathways and converge on IFN induction, the kinetics, amplitude, and downstream immunological consequences of these responses differ substantially and are major determinants of disease outcome.^44–46 The representative RNA and DNA viruses included in this review activate distinct but partially overlapping innate immune signaling pathways that ultimately converge on interferon production and inflammatory responses (Figure 2). Unlike many acute viral infections, HBV induces only limited activation of PRRs during the early phase of infection because viral proteins actively suppress cGAS-STING and TLR signaling pathways.

Figure 2.

Comparative signaling pathways activated during RNA and DNA viral infections. RNA viruses are primarily recognized by TLR3 and TLR7/8 and RIG-I and MDA5, leading to MAVS-mediated interferon signaling. In contrast, DNA viruses mainly activate TLR9 and the cGAS-STING pathway, resulting in induction of type I IFNs and inflammatory cytokines through IRF3 and NF-κB activation.

Divergent innate immune kinetics in RNA vs. DNA viruses

RNA viruses typically induce rapid and high-amplitude innate immune activation, primarily through RIG-I and TLR-mediated sensing of viral RNA intermediates. This early IFN response is a double-edged sword: it is essential for initial viral containment but can also contribute to immunopathology when excessively amplified. In contrast, DNA viruses often exhibit delayed or attenuated innate immune activation, reflecting both lower PAMP availability in the cytosol and active suppression of DNA sensing pathways such as cGAS-STING. This divergence in timing is a critical determinant of whether infection is resolved, persists, or transitions into chronicity.

Importantly, these differences suggest that timing of IFN induction is more influential than absolute IFN magnitude, a concept that is increasingly supported by clinical observations across multiple viral infections.⁴⁷

Acute RNA viruses: balancing antiviral defense and immunopathology

Influenza virus and SARS-CoV-2 represent two distinct paradigms of RNA virus host interaction.

Influenza virus triggers rapid activation of RIG-I and TLR7 signaling, resulting in early IFN production that limits viral replication. However, excessive cytokine production, particularly IL-6 and TNF-α, contributes to severe pulmonary inflammation and cytokine storm syndromes. Thus, influenza pathogenesis reflects a tight balance between antiviral efficacy and inflammatory injury.^48,49

In contrast, SARS-CoV-2 is characterized by a delayed interferon response followed by exaggerated inflammatory activation. This temporal dissociation between viral replication and immune activation is a key mechanistic driver of severe COVID-19. The virus’s ability to antagonize IFN induction through multiple non-structural proteins shifts the host response toward late-stage hyperinflammation rather than early viral control. This pattern highlights that immune evasion in RNA viruses is not necessarily the suppression of immunity but the temporal reprogramming of its activation.^50,51

Chronic RNA viral infection: immune exhaustion as a pathogenic driver

HIV infection illustrates a fundamentally different outcome of RNA virus host interaction. Unlike acute RNA viruses, HIV establishes chronic infection characterized by persistent but dysregulated interferon signaling. Early IFN responses contribute to partial viral control; however, sustained activation drives immune exhaustion, chronic inflammation, and progressive dysfunction of innate immune cells.

A key insight from HIV pathogenesis is that chronic innate immune activation is not protective but pathogenic, contributing to long-term tissue damage and immune collapse. This represents a shift from classical antiviral immunity toward a state of maladaptive inflammation, underscoring the importance of immune regulation over immune intensity.^52,53

Innate immune responses to DNA viruses

DNA viruses activate innate immune responses primarily through the detection of viral DNA within endosomal and cytoplasmic compartments. In contrast to RNA viruses, which are mainly recognized by RNA sensors such as RIG-I and MDA5, DNA viruses commonly stimulate TLR9 and cytosolic DNA sensing pathways including cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING). Activation of these pathways induces interferon production, inflammatory cytokine release, and recruitment of antiviral immune cells.

Several clinically important DNA viruses, including HSV, HBV, and CMV, establish latent or persistent infections and possess sophisticated immune evasion mechanisms that enable long term survival within the host. However, these characteristics are not universal among all DNA viruses and vary according to viral genome organization, genome size, replication strategy, and host interactions.

Comparative analysis of DNA viral infections demonstrates both common antiviral pathways and virus-specific immune modulation strategies.^54,55

DNA viruses: immune evasion, latency, and immune equilibrium

In contrast to RNA viruses, DNA viruses have evolved strategies that prioritize long-term persistence over acute replication advantage.

HSV represents a model of strong initial innate immune activation via cGAS-STING and TLR pathways, followed by efficient immune evasion and neuronal latency. The ability of HSV to silence viral gene expression within sensory neurons demonstrates that successful persistence depends not only on immune evasion but also on anatomical and transcriptional immune escape niches.⁵⁶

HBV, in contrast, exhibits a “stealth infection” phenotype characterized by minimal early innate immune activation. The weak induction of PRR signaling in hepatocytes allows HBV to replicate with limited immune detection. This suggests that in some DNA viruses, immune silence rather than immune suppression is the dominant evasion strategy, which strongly predisposes to chronic infection.⁵⁷

Recent studies indicate that the stealth nature of HBV is not solely attributable to its low immunostimulatory profile but also to active suppression of innate immune signaling. HBV proteins, particularly HBx and the viral polymerase, interfere with the cGAS-STING pathway by inhibiting STING activation and downstream TBK1-IRF3 signaling, thereby reducing type I IFN production. In addition, HBV suppresses TLR-mediated signaling and NF-κB activation, limiting the production of pro-inflammatory cytokines and antiviral mediators. These mechanisms contribute to immune tolerance, viral persistence, and the establishment of chronic infection, distinguishing HBV from many acute viral infections that elicit robust innate immune activation.

CMV occupies an intermediate position, inducing robust NK cell responses while simultaneously deploying extensive immune modulation strategies. Its ability to encode multiple immune evasion proteins illustrates a sophisticated equilibrium between immune activation and suppression, enabling lifelong latency with periodic reactivation.^58,59

Integrated perspective: determinants of viral outcome

Across the representative RNA and DNA viruses discussed in this review, a common pattern emerges: disease outcome is not determined solely by the presence of innate immune activation, but by its timing, localization, and regulatory balance.

Three major determinants can be identified:

1. Timing of interferon induction: Early IFN responses favor viral control, whereas delayed responses are associated with immunopathology or viral persistence.

2. Magnitude of inflammatory signaling: Excessive activation contributes to tissue damage (e.g., influenza, COVID-19), while insufficient activation enables viral escape (e.g., HBV).

3. Viral immune evasion strategy: Viruses either suppress signaling, delay responses, or establish latency to circumvent host immunity.

This framework provides a unified explanation for the heterogeneous outcomes observed across viral infections, ranging from acute self-limiting disease to chronic persistence and latency.^58–61

Key insight

A major conceptual insight emerging from this comparative analysis is that innate immunity functions as a temporal system rather than a static defense mechanism. Therefore, successful antiviral defense depends not only on pathway activation but on the precise orchestration of immune kinetics relative to viral replication dynamics. This temporal mismatch between viral strategies and host responses may represent one of the most critical but underappreciated determinants of viral pathogenesis and therapeutic success. The major innate immune characteristics, interferon responses, and immune evasion mechanisms associated with different viral infections are comparatively summarized in Table 2.

Table 2.

Comparative analysis of innate immune responses and immune evasion mechanisms in major viral infections.

Virus	Genome Type	Major PRRs Activated	Dominant Innate Response	Key Cytokines/IFNs	Main Immune Evasion Strategy
Influenza virus	ssRNA	TLR7, RIG-I	Rapid IFN-I response	IFN-α/β, IL-6, TNF-α	NS1-mediated interferon suppression
SARS-CoV-2	ssRNA	TLR3, MDA5, RIG-I	Delayed interferon response	IL-6, IL-1β, TNF-α	JAK-STAT inhibition, IFN antagonism
HIV	Retrovirus	TLR7, RIG-I	Chronic immune activation	IFN-I, TNF-α	Immune exhaustion, antigenic variation
HSV	dsDNA	TLR9, cGAS-STING	Strong DNA sensing response	IFN-β, IL-6	Latency establishment, STING inhibition
HBV	dsDNA	Weak PRR activation	Limited innate activation	IL-10, weak IFN response	Immune tolerance, IFN suppression
CMV	dsDNA	TLR9, cGAS-STING	Strong NK cell activation	IFN-α, TNF-α	MHC-I mimicry, NK cell evasion

Viral immune evasion strategies

Viral immune evasion represents one of the most critical determinants of infection outcome, shaping whether host responses lead to viral clearance, persistence, or immunopathology. Rather than being passive targets of host immunity, viruses actively reshape innate immune signaling networks to create a permissive environment for replication. Importantly, immune evasion is not limited to immune suppression; it often involves temporal reprogramming, immune redirection, or controlled immune activation, depending on the viral life cycle and persistence strategy.

A key conceptual insight is that successful viral survival depends on the ability to disrupt the early kinetics of innate immune activation, particularly IFN responses, which serve as the central hub of antiviral defense.⁶² Viruses employ diverse strategies to interfere with innate immune signaling pathways, suppress antiviral responses, and establish persistent infection (Figure 3).

Figure 3.

Major viral immune evasion mechanisms targeting innate antiviral immunity. Viruses interfere with multiple stages of innate immune responses by inhibiting PRR signaling, suppressing interferon production and JAK-STAT signaling, impairing NK cell activity, modulating cytokine responses, and establishing latent or persistent infections.

Targeting the initiation of innate immune sensing

The earliest point of viral-host conflict occurs at the level of pathogen recognition. PRRs function as gatekeepers of antiviral immunity; therefore, many viruses evolve strategies that prevent or delay their activation.

RNA viruses frequently interfere with RLR signaling, thereby disrupting detection of viral RNA intermediates. For example, influenza virus NS1 protein inhibits upstream activation of RIG-I, effectively delaying the initiation of antiviral signaling.^63–65 Similarly, SARS-CoV-2 employs multiple non-structural proteins to disrupt mitochondrial antiviral signaling and downstream interferon regulatory pathways, resulting in a functional “blindness” of the innate immune system during early infection.^66,67 Recent evidence further demonstrates that diverse RNA viruses have evolved sophisticated strategies to suppress innate immune signaling. For example, Seneca Valley virus (SVV) antagonizes multiple components of the host antiviral response, including RIG-I/MDA5-, MAVS-, TBK1-, IRF3-, and NF-κB-mediated signaling pathways, thereby suppressing type I interferon production and facilitating viral replication. These findings further support the concept that viral immune evasion commonly targets conserved innate immune signaling pathways despite differences in viral taxonomy and replication strategies.⁶⁸ In contrast, DNA viruses predominantly target cytosolic DNA sensing pathways, particularly the cGAS-STING axis. By inhibiting these pathways, viruses such as HSV and HBV prevent the transcriptional activation of IFNI at the source of DNA detection.^69,70

These observations highlight a unifying principle: viruses do not merely suppress immunity; they selectively disable immune “sensors” that determine the timing of host responses.

Reprogramming interferon signaling networks

IFNs represent the central effector output of innate immunity, and thus their disruption is a common evolutionary target across viral families.²¹ Viral interference occurs at multiple hierarchical levels, including interferon induction, receptor signaling, and downstream ISG expression.⁷¹

A notable pattern emerges when comparing viral strategies: acute RNA viruses tend to delay or transiently suppress IFN responses, while chronic viruses induce long-term dysregulation rather than complete inhibition. SARS-CoV-2⁷² and Influenza virus⁷³ exemplify early suppression of IFN signaling, allowing uncontrolled viral replication before host defenses are fully engaged.

Conversely, chronic viral infections such as HIV are characterized by persistent interferon signaling that gradually shifts from protective to pathological.⁷⁴ This chronic activation contributes to immune exhaustion, indicating that prolonged IFN exposure is not inherently beneficial but may instead become a driver of immune dysfunction.

Thus, interferon signaling should be viewed not as a binary antiviral switch, but as a dose- and time-dependent regulatory system whose dysregulation defines disease trajectory.

Modulation of cytokine networks and immunopathology

Beyond interferons, viruses actively reshape cytokine landscapes to influence tissue environments. Some viruses suppress inflammatory signaling to evade detection, while others induce excessive cytokine production that promotes tissue damage and facilitates dissemination.⁷⁵ This duality is particularly evident in severe respiratory RNA viral infections, where excessive production of IL-6, TNF-α, and other cytokines leads to hyperinflammatory states. Importantly, this cytokine excess is not simply a host failure but often reflects virus-driven dysregulation of immune feedback loops.^76,77

Herpesviruses and CMV further extend this concept by encoding proteins that mimic or modulate host cytokine systems, effectively rewiring immune communication networks. These strategies indicate that cytokine manipulation is not a secondary effect of infection but a primary evolutionary adaptation for immune control.^78,79

Subversion of NK cell surveillance

NK cells represent a rapid cytotoxic arm of innate immunity, and their targeting reflects the evolutionary pressure imposed by early immune surveillance.

Viruses commonly manipulate MHC-I expression to evade both adaptive and innate immune recognition. However, this creates a paradox: while reduced MHC-I helps escape T cells, it increases susceptibility to NK cell-mediated killing. To resolve this, many viruses develop additional mechanisms to inhibit NK activation directly.⁸⁰

CMV exemplifies a highly sophisticated solution by encoding multiple immunomodulatory proteins that engage inhibitory NK receptors, effectively converting an activating signal into a suppressive one.⁸¹ In chronic infections such as HIV, NK cell dysfunction and exhaustion further illustrate how prolonged antigen exposure reshapes innate cytotoxicity into a compromised state.⁸² This highlights a broader principle: successful viral persistence requires simultaneous evasion of both adaptive immunity and innate cytotoxic surveillance systems.

Latency, persistence, and immune silence

Perhaps the most evolutionarily successful immune evasion strategy is the establishment of latency or persistent infection. Rather than continuously confronting the immune system, viruses such as HSV and CMV adopt a strategy of transcriptional silence and spatial sequestration, minimizing antigen exposure and immune detection.

HSV latency in sensory neurons illustrates how anatomical immune privilege can be exploited to ensure long-term persistence.⁸³ In contrast, HBV achieves persistence not through latency but through immune invisibility, generating insufficient PAMPs to trigger robust innate activation.

These distinct strategies reveal two fundamentally different evolutionary solutions: one based on hiding from immunity, and the other based on failing to be detected in the first place. Chronic infections such as HIV further demonstrate that persistence is often reinforced by progressive immune exhaustion, where host defenses are gradually weakened over time.⁸⁴

Integrated perspective: immune evasion as temporal control of immunity

Across viral families, immune evasion strategies converge on a central theme: the manipulation of immune timing and intensity. Rather than uniformly suppressing immunity, viruses fine-tune host responses to optimize replication windows, persistence potential, and transmission efficiency.

RNA viruses primarily rely on early-phase interference with interferon induction, whereas DNA viruses more frequently exploit long-term strategies such as latency and immune modulation. These differences reflect fundamentally distinct evolutionary pressures shaped by replication speed vs. persistence capacity. Major viral immune evasion mechanisms targeting innate antiviral signaling pathways and immune cell functions are summarized in Table 3.

Table 3.

Major viral immune evasion strategies targeting innate antiviral immunity.

Virus	Targeted Immune Pathway	Immune Evasion Mechanism	Consequence
Influenza virus	RIG-I signaling	NS1-mediated inhibition of interferon production	Reduced antiviral response
SARS-CoV-2	JAK-STAT pathway	Suppression of interferon signaling	Delayed antiviral immunity
HIV	NK cell function	Immune exhaustion and chronic activation	Persistent infection
HSV	cGAS-STING pathway	STING inhibition and latency establishment	Viral persistence
HBV	Interferon pathways	Weak PRR activation and immune tolerance	Chronic infection
CMV	NK cell recognition	MHC-I mimicry and inhibitory signaling	Escape from NK cell killing

Key conceptual insight

A unifying insight from comparative analysis is that viral immune evasion should be viewed as a strategy of dynamic immune reprogramming rather than simple immune inhibition. The outcome of infection is therefore determined not only by whether innate immunity is activated, but by how viruses reshape its kinetics, amplitude, and duration.

This framework explains why similar immune pathways can lead to vastly different clinical outcomes across viral infections, ranging from acute self-limiting disease to chronic persistence and latent reactivation.

Cytokine storm and immunopathology

Innate immune activation is indispensable for restricting viral replication and initiating adaptive immunity. However, when antiviral responses become excessive, prolonged, or poorly regulated, they may transition from protective mechanisms into major drivers of tissue injury. Thus, the outcome of viral infection is determined not only by the effectiveness of immune activation but also by the host’s ability to control its magnitude and duration.

One of the most severe manifestations of dysregulated innate immunity is cytokine storm syndrome, a hyperinflammatory state characterized by uncontrolled production of pro-inflammatory cytokines, chemokines, and other inflammatory mediators. Rather than representing a simple increase in cytokine levels, cytokine storm reflects a profound breakdown of immune regulatory networks that normally limit inflammation after pathogen recognition. Excessive activation of macrophages, monocytes, neutrophils, dendritic cells, and other innate immune populations amplifies inflammatory signaling, creating self-sustaining feedback loops that can lead to widespread tissue damage and organ dysfunction.^84,85

Importantly, cytokine storm is increasingly recognized as a consequence of immune dysregulation rather than direct viral cytotoxicity alone. In many severe viral infections, host-mediated inflammatory injury contributes more substantially to disease progression than viral replication itself. This concept has been particularly evident in severe COVID-19 and highly pathogenic influenza infections, where elevated levels of cytokines such as IL-6, TNF-α, IL-1β, and various chemokines are associated with acute respiratory distress syndrome (ARDS), vascular injury, coagulopathy, and multiorgan failure.⁵⁴

A comparative analysis of viral infections suggests that the risk of immunopathology is closely linked to the kinetics of interferon responses. Early and appropriately regulated interferon production generally promotes viral control while limiting excessive inflammation. In contrast, delayed or ineffective interferon responses may permit extensive viral replication, resulting in secondary hyperactivation of inflammatory pathways. This phenomenon has been particularly well documented in SARS-CoV-2 infection, where impaired early interferon responses are frequently followed by exaggerated inflammatory reactions.

Multiple innate immune cell populations contribute to cytokine storm development. Activated macrophages produce large quantities of IL-6, TNF-α, and other inflammatory mediators, while excessive neutrophil recruitment promotes tissue injury through reactive oxygen species production and NET formation. Although these mechanisms initially serve protective functions, persistent activation can damage host tissues and amplify inflammatory cascades. Consequently, the same immune pathways responsible for antiviral defense may become major contributors to disease severity when regulatory mechanisms fail.

Interestingly, marked cytokine storm syndromes are more commonly associated with acute RNA viral infections than with most latent DNA viral infections. Rapid viral replication, strong PRR activation, and intense inflammatory signaling frequently characterize severe infections caused by influenza virus and SARS-CoV-2. In contrast, many DNA viruses have evolved strategies that favor immune modulation, latency, or immune tolerance, thereby reducing the likelihood of overwhelming acute inflammatory responses. This distinction further highlights the importance of immune kinetics in determining clinical outcomes.

Collectively, these observations support the concept that immunopathology represents a consequence of imbalanced innate immunity rather than insufficient immunity alone. Effective antiviral defense therefore requires a delicate equilibrium between pathogen elimination and inflammatory control. Understanding the mechanisms that govern this balance is essential for developing targeted immunomodulatory therapies aimed at reducing tissue damage while preserving antiviral protection.^85,86 The balance between effective antiviral immunity and controlled inflammation is therefore crucial for maintaining host survival during infection. The mechanisms underlying cytokine storm syndrome and immune mediated tissue damage during severe viral infections are illustrated in Figure 4.

Figure 4.

Mechanisms of cytokine storm syndrome and immune-mediated tissue damage during severe viral infections. Viral recognition by PRRs induces inflammatory cytokine production and recruitment of innate immune cells. Controlled inflammation contributes to antiviral defense and tissue repair, whereas excessive immune activation leads to cytokine storm, NET formation, ARDS, thrombosis, and multiorgan damage.

Key Insight: A major lesson emerging from severe viral infections is that disease severity is often determined not only by the virus itself, but by the host response to it. Cytokine storm exemplifies how innate immune pathways that are essential for protection can become pathogenic when their timing, intensity, and regulation are disrupted.

Mechanisms of cytokine storm development

Cytokine storms occur when innate immune activation becomes excessive and self-amplifying. Viral recognition by PRRs stimulates immune cells and infected tissues to produce inflammatory mediators such as IL-6, IL-1β, TNF-α, interferons, and chemokines. Under normal conditions, cytokine production is tightly regulated and contributes to viral clearance. However, persistent viral replication, delayed interferon responses, excessive immune cell recruitment, and dysregulated signaling pathways may trigger uncontrolled inflammation.

Importantly, cytokine storm should not be viewed merely as excessive cytokine production but rather as a failure of immune regulatory mechanisms that normally limit inflammation after pathogen recognition. Therefore, disease severity often reflects the inability to resolve inflammation rather than the magnitude of the initial antiviral response alone.

Activated macrophages, monocytes, neutrophils, and DCs play central roles in cytokine storm development. These cells release large quantities of inflammatory mediators that recruit additional immune cells to infected tissues, thereby amplifying inflammation and tissue injury. Excessive cytokine production increases vascular permeability, promotes coagulation abnormalities, and induces cellular damage in multiple organs. In severe cases, cytokine storms can progress to ARDS, septic shock, and multiorgan failure.^87,88

Cytokine storm in SARS-CoV-2 infection

SARS-CoV-2 infection is one of the most extensively studied examples of virus-induced cytokine storm syndrome. Severe COVID-19 is characterized by elevated serum levels of IL-6, IL-1β, TNF-α, granulocyte-macrophage colony-stimulating factor (GM-CSF), and various chemokines. A delayed or impaired type I interferon response during early infection allows extensive viral replication, followed by exaggerated inflammatory activation in later stages. Hyperactivated macrophages and infiltrating neutrophils contribute significantly to pulmonary inflammation and tissue destruction.^89,90 NETs have also been implicated in vascular thrombosis and lung injury during severe COVID-19. Excessive inflammation damages alveolar epithelial cells and endothelial tissues, leading to impaired gas exchange and respiratory failure.⁹¹ Clinical severity in COVID-19 strongly correlates with elevated inflammatory biomarkers, including C-reactive protein (CRP), ferritin, and IL-6 levels.⁹² Consequently, anti-inflammatory therapies targeting cytokine signaling pathways, particularly IL-6 inhibitors and corticosteroids, have shown therapeutic benefits in severe disease.

These observations suggest that severe COVID-19 is driven by a temporal mismatch between viral replication and host immune activation. Delayed interferon responses permit extensive viral expansion, whereas subsequent hyperinflammation contributes disproportionately to tissue damage.

Cytokine storm in influenza virus infection

Highly pathogenic influenza viruses can also induce severe cytokine storm syndromes. During influenza infection, rapid activation of innate immune pathways stimulates robust production of type I IFNs and inflammatory cytokines. While moderate inflammation contributes to viral clearance, excessive cytokine release may result in severe pulmonary pathology. Elevated levels of IL-6, TNF-α, IFN-γ, and chemokines recruit large numbers of neutrophils and monocytes into lung tissues, causing alveolar damage and edema. Certain influenza strains, such as H5N1 avian influenza, are particularly associated with hypercytokinemia and high mortality rates. Host immune mediated tissue injury rather than direct viral cytotoxicity is often the primary cause of severe disease in these infections.^93,94

Compared with SARS-CoV-2, influenza virus generally induces earlier interferon responses, yet severe disease may still arise when inflammatory amplification exceeds protective antiviral functions. This highlights that both insufficient and excessive innate immune activation can result in adverse clinical outcomes.

Chronic inflammation in persistent viral infections

Not all viral immunopathology occurs as acute cytokine storms. Chronic viral infections such as HIV and HBV are associated with long-term immune activation and persistent low-grade inflammation. In HIV infection, continuous stimulation of innate immune pathways contributes to immune exhaustion, T-cell dysfunction, and increased susceptibility to opportunistic infections. Chronic interferon signaling and inflammatory cytokine production are major drivers of disease progression.⁹⁵ Similarly, chronic HBV infection leads to persistent hepatic inflammation, which contributes to fibrosis, cirrhosis, and hepatocellular carcinoma.⁹⁶ In these cases, long-term immune-mediated tissue damage plays a more important role than acute hyperinflammation.

In contrast to acute cytokine storm syndromes, chronic viral infections illustrate how sustained low-grade inflammation can gradually drive tissue injury over years. Thus, immunopathology may result from either excessive short-term inflammation or prolonged immune activation, depending on the viral persistence strategy.

Protective vs. pathological inflammation

Innate immune activation during viral infection represents a double-edged sword. Controlled inflammatory responses are essential for viral clearance, tissue repair, and activation of adaptive immunity, whereas excessive or prolonged inflammation contributes to immunopathology and organ dysfunction. Emerging evidence suggests that disease severity is determined not simply by the strength of immune activation but by its timing, duration, and regulatory balance.

A comparative analysis of viral infections indicates that acute RNA viruses frequently induce rapid inflammatory responses that may culminate in cytokine storm syndromes, whereas persistent viruses such as HIV and HBV are more commonly associated with chronic immune activation and progressive tissue damage. Despite these differences, both outcomes arise from dysregulated innate immune responses.

Therefore, successful antiviral immunity requires a balance between pathogen elimination and inflammatory control. Understanding how viruses disrupt this balance may facilitate the development of targeted immunomodulatory therapies that reduce tissue injury while preserving antiviral protection.^97,98

Therapeutic implications and future antiviral strategies

Comparative analysis of viral infections demonstrates that disease outcome is largely determined by the balance between antiviral immunity and immune-mediated pathology. Consequently, modern antiviral strategies increasingly extend beyond direct inhibition of viral replication and aim to modulate host immune responses. This shift reflects a growing recognition that successful treatment depends not only on reducing viral burden but also on restoring appropriate immune regulation.⁹⁹

An important lesson emerging from studies of RNA and DNA viruses is that therapeutic interventions must consider the timing, magnitude, and context of innate immune activation. Strategies that enhance innate immunity may improve viral control during early infection, whereas suppression of excessive inflammation may be required during later stages of disease. Therefore, innate immunity represents both a therapeutic target and a therapeutic challenge.¹⁰⁰

Interferon-based therapies

IFNs are among the earliest antiviral agents used in the treatment of viral infections due to their broad-spectrum antiviral activity. Type I interferons, particularly IFN-α, have been widely used for chronic HBV and HCV infections. Interferon therapy enhances the expression of ISGs, thereby inhibiting viral replication and promoting antiviral immune responses. Early administration of IFNs may be particularly beneficial during acute viral infections when viral replication is still limited.¹⁰¹ During the COVID-19 pandemic, several studies investigated the therapeutic potential of IFNs against SARS-CoV-2 infection. Results suggested that early interferon administration could improve antiviral responses, whereas delayed treatment during hyperinflammatory stages might worsen immunopathology.¹⁰² Despite their broad-spectrum antiviral activity, interferon therapies are associated with significant limitations that restrict their widespread clinical use. In addition to common adverse effects such as fatigue, flu-like symptoms, hematological abnormalities, and chronic inflammation, interferon treatment may induce neuropsychiatric complications, including depression, anxiety, cognitive impairment, and sleep disturbances, particularly during prolonged therapy. Autoimmune manifestations, such as autoimmune thyroiditis and other immune-mediated disorders, have also been reported in susceptible individuals. Furthermore, the poor tolerability of interferon therapy frequently results in dose reduction or premature treatment discontinuation, thereby limiting its long-term efficacy. Another important challenge is the strong dependence of therapeutic efficacy on the timing of administration. Early interferon treatment, when viral replication is still limited, generally enhances antiviral immunity and improves clinical outcomes, whereas delayed administration during the hyperinflammatory phase may exacerbate immune-mediated tissue injury rather than provide clinical benefit. Therefore, careful patient selection, optimal treatment timing, and dosage optimization are essential for maximizing the therapeutic benefits of interferon-based strategies while minimizing adverse effects.

Collectively, clinical experience with interferon therapy highlights a fundamental principle of antiviral immunology: the effectiveness of IFN is highly dependent on treatment timing. Early interferon administration may restore antiviral defenses and limit viral replication, whereas delayed administration during hyperinflammatory stages may exacerbate tissue damage. Thus, therapeutic success is determined not only by the antiviral properties of IFNs but also by their temporal alignment with disease progression.

Targeting cytokine storm and hyperinflammation

Because excessive inflammation contributes substantially to disease severity in viral infections, anti-inflammatory therapies have become important components of clinical management, particularly in severe COVID-19 and influenza cases. IL-6 inhibitors such as tocilizumab have demonstrated clinical benefits in patients with severe COVID-19-associated cytokine storm syndrome. Corticosteroids, especially dexamethasone, reduce mortality in critically ill COVID-19 patients by suppressing excessive inflammatory responses.¹⁰³ Other therapeutic strategies targeting inflammatory pathways include Janus kinase (JAK) inhibitors,¹⁰⁴ TNF-α blockers,¹⁰⁵ and inflammasome inhibitors.¹⁰⁶ These agents aim to limit immune-mediated tissue damage while preserving essential antiviral immunity. However, excessive immunosuppression may impair viral clearance and increase susceptibility to secondary infections. Consequently, balancing antiviral defense with inflammation control remains a major therapeutic challenge.

The success of anti-inflammatory therapies in severe viral infections demonstrates that disease severity is often driven by host immune dysregulation rather than viral replication alone. However, excessive suppression of inflammatory pathways may compromise antiviral immunity. These observations emphasize the need for therapeutic approaches capable of selectively reducing pathological inflammation while preserving protective immune functions. Although anti-inflammatory therapies effectively reduce immune-mediated tissue injury, excessive or prolonged immunosuppression may impair viral clearance, delay pathogen elimination, increase the risk of secondary bacterial or fungal infections, and potentially compromise long-term antiviral immunity. Therefore, careful patient selection, biomarker-guided therapeutic decisions, and appropriate timing of treatment are essential to maximize clinical benefit while minimizing adverse outcomes.

PRR agonists and innate immune modulators

Activation of PRRs represents a promising antiviral strategy because PRR stimulation can enhance innate immune responses and improve viral clearance. TLR agonists have been investigated as antiviral agents and vaccine adjuvants. For example, TLR7 and TLR9 agonists stimulate interferon production and promote antiviral immunity against chronic viral infections such as HBV and HIV.^107–109 Similarly, activation of the cGAS-STING pathway has attracted considerable interest in antiviral and anticancer immunotherapy research. STING agonists can enhance interferon responses and improve immune-mediated elimination of infected cells.¹¹⁰ These approaches represent a shift from virus-directed therapies toward host-directed interventions. By targeting conserved innate immune pathways rather than specific viral proteins, PRR agonists may provide broader protection against diverse viral pathogens and potentially reduce the impact of viral mutation and immune escape. Innate immune modulators may also enhance vaccine efficacy by promoting stronger early immune activation and improved adaptive immune responses.³ Unlike direct-acting antivirals, PRR agonists are less susceptible to classical viral drug resistance because they target host innate immune pathways rather than viral proteins. Nevertheless, several factors may limit their long-term clinical efficacy, including receptor desensitization following repeated stimulation, activation of negative feedback regulators of innate immune signaling (such as suppressor of cytokine signaling (SOCS) proteins and A20), excessive systemic inflammation, and viral immune evasion mechanisms that inhibit downstream signaling pathways. Therefore, optimizing agonist selection, dosage, and treatment timing remains essential for maximizing therapeutic efficacy while minimizing adverse immune activation.

Monoclonal antibodies and antiviral immunotherapy

Monoclonal antibodies provide highly specific antiviral protection by neutralizing viral particles or modulating immune pathways. Neutralizing antibodies targeting viral surface proteins have been successfully used against SARS-CoV-2 and respiratory syncytial virus (RSV).^111,112 In addition to direct antiviral activity, monoclonal antibodies targeting inflammatory cytokines can reduce immunopathology during severe infections. For example, antibodies against IL-6 receptors and granulocyte-macrophage colony stimulating factor (GM-CSF) are used to control hyperinflammation in severe COVID-19.^113,114 Advances in antibody engineering continue to improve antiviral efficacy, specificity, and duration of protection.

The expanding role of monoclonal antibodies illustrates the growing convergence between antiviral therapy and immunomodulation. Future antibody-based approaches may increasingly combine direct antiviral activity with precise regulation of host inflammatory responses.

Vaccine development and innate immunity

Innate immune activation is essential for effective vaccine induced immunity. Vaccine adjuvants often function by stimulating PRRs and promoting cytokine production that enhances adaptive immune responses.¹¹⁵ Messenger RNA (mRNA) vaccines developed against SARS-CoV-2 represent a major advancement in vaccine technology. These vaccines stimulate innate immune sensors while simultaneously inducing robust antigen specific immunity.^116,117 Understanding innate immune signaling pathways has also facilitated the development of safer and more effective adjuvants capable of generating durable protective responses with reduced adverse effects. Future vaccine strategies may increasingly incorporate personalized approaches based on host immune profiles and genetic factors influencing innate immunity.

The success of mRNA vaccines has further demonstrated that innate immune activation is not merely a prerequisite for adaptive immunity but can itself be engineered and optimized to enhance vaccine efficacy. This concept is likely to influence the design of next-generation antiviral vaccines and adjuvant platforms.

Future perspectives

Future advances in antiviral therapy will likely depend on a deeper understanding of the dynamic interactions between viruses and innate immune pathways. Emerging technologies, including single-cell transcriptomics, systems immunology, spatial biology, and artificial intelligence, are providing unprecedented opportunities to characterize immune responses at high resolution.

A major future challenge will be the development of precision immunotherapies capable of tailoring treatment according to individual immune signatures rather than relying solely on pathogen-specific approaches. Such strategies may allow clinicians to identify patients who would benefit from immune stimulation, anti-inflammatory interventions, or combined therapeutic approaches.

Building upon the central concept of temporal immune regulation presented in this review, future research should focus on identifying dynamic immune biomarkers that accurately reflect the kinetics of innate immune responses throughout the course of viral infection. Integrating single-cell transcriptomics, spatial biology, proteomics, and systems immunology with longitudinal clinical studies may facilitate the characterization of stage-specific immune signatures associated with viral clearance, immune evasion, or immunopathology. Such biomarkers could enable real-time monitoring of immune status and guide personalized therapeutic interventions. Furthermore, future immunomodulatory strategies should move beyond generalized immune stimulation or suppression toward timed interventions that selectively enhance antiviral immunity during early infection while limiting pathological inflammation during later stages. Artificial intelligence-driven predictive models integrating viral, immunological, and host genomic data may further improve patient stratification, optimize treatment timing, and accelerate the development of precision antiviral immunotherapies.

Importantly, comparative studies of RNA and DNA viruses suggest that the most effective future therapies may not simply enhance or suppress immunity but rather restore appropriate immune timing and regulation. Consequently, modulation of innate immune kinetics may emerge as a central principle of next-generation antiviral treatment strategies.

Host genomic factors and interindividual variability

Host genomic factors are increasingly recognized as critical determinants of innate immune responses and clinical outcomes following viral infections. While virus-specific characteristics strongly influence immune activation and immune evasion, substantial interindividual variability arises from genetic differences in the host immune system. Polymorphisms in genes encoding pattern recognition receptors (PRRs), including TLR3, TLR7, DDX58 (RIG-I), IFIH1 (MDA5), and MB21D1 (cGAS), have been associated with altered viral recognition, interferon production, and susceptibility to severe viral disease. Likewise, genetic variation in components of the interferon signaling cascade, such as IFNAR1, STAT1, IRF3, and IRF7, can influence antiviral responses and disease progression.

In addition, polymorphisms in cytokine genes, chemokine receptors, and human leukocyte antigen (HLA) loci contribute to differences in immune regulation, viral clearance, and treatment outcomes. These host genetic factors partly explain the marked heterogeneity observed among individuals infected with influenza virus, SARS-CoV-2, HIV, HBV, HSV, and CMV, despite infection with the same pathogen. Increasing evidence also suggests that integrating host genomic information with viral and immunological characteristics may improve risk stratification, predict therapeutic responses, and facilitate the development of precision immunotherapies and personalized antiviral strategies.

Overall, comparative analyses of viral infections should consider both viral diversity and host genetic variability, as the interaction between these factors ultimately shapes innate immune responses, disease severity, and clinical outcomes.

Conclusion

Innate immunity represents the foundation of host defense against viral infections and plays a central role in determining whether infection is successfully controlled, progresses to severe disease, or establishes long-term persistence. Although diverse viruses activate common innate immune sensing pathways through PRRs, the present comparative analysis demonstrates that substantial differences exist in the timing, magnitude, and regulation of downstream immune responses.

A major finding emerging from comparisons across viral families is that the outcome of infection is not determined solely by the activation of innate immunity, but by the balance between antiviral protection and immune-mediated pathology. Among the representative viruses examined in this review, RNA viruses such as influenza virus and SARS-CoV-2 generally induce rapid innate immune activation and robust inflammatory responses, whereas many DNA viruses, including HSV, HBV, and CMV, have evolved more sophisticated mechanisms for immune modulation, latency, and persistence. These distinct evolutionary strategies result in fundamentally different patterns of host-pathogen interaction despite engagement of overlapping immune pathways.

Importantly, this review highlights that interferon responses occupy a pivotal position in antiviral immunity. Early and appropriately regulated interferon signaling promotes viral control and limits disease progression, whereas delayed, excessive, or chronic activation may contribute to immunopathology, immune exhaustion, and tissue damage. Consequently, the kinetics of innate immune activation appear to be as important as its magnitude in determining clinical outcomes.

Another key insight is that viral immune evasion should not be viewed simply as suppression of host immunity. Rather, many viruses actively reprogram innate immune responses by altering their timing, intensity, and downstream signaling consequences. This dynamic interaction ultimately shapes viral persistence, disease severity, and therapeutic responsiveness.

From a translational perspective, comparative analysis of RNA and DNA viruses suggests that future antiviral strategies should move beyond pathogen-centered approaches and increasingly focus on restoring appropriate immune regulation. The success of interferon-based therapies, cytokine inhibitors, PRR agonists, monoclonal antibodies, and next-generation vaccine platforms demonstrates the growing importance of host-directed interventions in antiviral medicine.

Despite substantial progress, important knowledge gaps remain regarding the mechanisms governing immune dysregulation, viral persistence, and interindividual variability in antiviral responses. Future studies integrating systems immunology, single-cell technologies, artificial intelligence, and precision medicine approaches will likely provide deeper insights into host-virus interactions and facilitate the development of more personalized therapeutic strategies.

In conclusion, although RNA and DNA viruses activate broadly similar innate sensing pathways, differences in interferon kinetics, inflammatory amplification, and immune evasion mechanisms ultimately determine infection outcomes and therapeutic responses. Understanding these shared and distinct features of innate immunity provides a conceptual framework for the development of more effective antiviral and immunomodulatory interventions against both existing and emerging viral threats.

Funding Statement

The author(s) reported there is no funding associated with the work featured in this article.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

M.M.A.S wrote and reviewed the main manuscript.

Data availability

All data generated or analyzed during the study are included in the submitted manuscript information files. There are no restrictions on data availability.

Supplementary Information

Supplemental data for this article can be accessed online at https://doi.org/10.1080/21645515.2026.2714657