The time has come: integrating vaccination and vector control for Aedes-borne disease prevention

Dengue control has entered a new phase. Vaccination and vector control are often considered separate interventions, yet they act at different and potentially complementary points in the transmission cycle. Vaccination provides individual-level protection against dengue in eligible populations, whereas vector control reduces mosquito abundance, vector competence, or transmission potential, thereby reducing population-level exposure. The key question is therefore not whether either approach has value in isolation, but how vaccination, biological vector control, and evidence-based routine vector-control measures can be combined within integrated prevention programs.

Findings by Chang and colleagues,¹ published in the October 2026 issue of eBioMedicine, strengthen the case for Wolbachia-based biological vector control as an important component of such programs. Wolbachia is a diverse genus of obligate intracellular, maternally transmitted Gram-negative α-proteobacteria (order Rickettsiales) that infects many arthropod species. Its reproductive effects, particularly cytoplasmic incompatibility, have been harnessed through two distinct biological-control approaches: population suppression and population replacement. In the population-suppression approach evaluated by Chang and colleagues, male wAlbB-infected Aedes aegypti were combined with irradiation (IIT-SIT) to suppress wild-type mosquito populations. The importance of this trial is therefore not only entomological; it provides large-scale cluster randomised evidence that mosquito population suppression can translate into substantial reductions in dengue incidence. Dengue incidence was similar in intervention and control clusters before implementation (18.14 vs 18.63 cases per 100,000, respectively), supporting baseline comparability. During the intervention period, incidence was substantially lower in intervention clusters than in controls (11.31 vs 36.57 cases per 100,000, respectively). Six months after releases began, reductions in total dengue incidence ranged from 27.64% to 83.78% across clusters, with an estimated 2351 cases averted compared with 1037 reported cases in intervention clusters. Reductions in epidemiologically linked dengue incidence were particularly striking, ranging from 60.90% to 99.8%. However, attenuation of protection during the 2023 interepidemic period highlights the dynamic nature of dengue transmission and the need for sustained surveillance.¹

Population replacement uses a different mechanism, releasing Wolbachia-carrying females and males so that the infection becomes established in local Ae. aegypti populations and reduces vector competence. This approach already has substantial field evidence. The AWED cluster-randomised trial in Yogyakarta reported 77.1% protective efficacy against virologically confirmed dengue and 86.2% against dengue hospitalisation following wMel introgression.² In Malaysia, initial wAlbB releases in six dengue hotspots in Greater Kuala Lumpur achieved sustained establishment and were associated with an estimated 40% reduction in dengue incidence. Subsequent operational deployment across 20 release sites, compared with 76 control sites, was associated with a 62.4% reduction, with greater reductions at higher Wolbachia frequencies.³ Together, these findings show that Wolbachia-based control is not a single intervention but a platform encompassing both population suppression and population replacement.

The distinction between vaccination and vector control is important. Vaccination is pathogen-specific, whereas Aedes control is vector-targeted and potentially pathogen-agnostic. This does not imply universal protection: benefits depend on the contribution of the targeted vector species to transmission and the effectiveness of the intervention against that vector. For Zika and chikungunya, for which population-level vaccine protection is absent or more limited in many settings, sustained Aedes control may therefore provide an especially important additional layer of protection. Supporting this broader potential, wMel population replacement in Niterói, Brazil, was associated with reductions of 69% in dengue, 56% in chikungunya, and 37% in Zika incidence across the aggregate release area.⁴

The expansion of Aedes mosquitoes, together with climate variability, urbanisation, population mobility, and other environmental and social changes, is facilitating transmission in new and previously affected settings. The scale of recent epidemics further illustrates the limitations of relying on a single intervention. In 2024, more than 14.6 million dengue cases and over 12,000 dengue-related deaths were reported globally,⁵ including more than 13 million cases in the Americas. A resilient public-health strategy should therefore operate across individual, vector, and population levels.

Importantly, the IIT-SIT trial in Singapore^1,6 was conducted while baseline vector-control measures continued in all clusters, supporting a model in which Wolbachia-based interventions strengthen rather than displace established programs. Integrated Aedes management should therefore retain entomological and epidemiological surveillance, source reduction, community engagement, and appropriately targeted larval or adult mosquito control. These measures can provide complementary layers of protection adapted to local epidemiological and entomological conditions.

A crucial evidence gap remains: vaccination and biological vector control have largely been evaluated independently, and evidence from populations in which both are deployed simultaneously is scarce. Whether their effects are additive, synergistic, or context-dependent is therefore unknown. Future studies should evaluate integrated packages combining vaccination, biological vector control, and evidence-based routine Aedes control, while measuring effects on symptomatic and severe dengue, hospitalisation, mortality, serotype-specific outcomes, indirect protection, entomological outcomes, durability, and cost-effectiveness. Studies should also assess potential effects on Zika, chikungunya, and other Aedes-borne infections.

The objective should not be to identify a single replacement for existing tools, but to determine which combinations, intensities, and sequences of interventions produce the greatest and most durable reductions in disease burden under different epidemiological conditions. Biological vector control should therefore be considered neither an alternative to vaccination nor a replacement for routine vector control, but an additional layer within an integrated public-health platform for Aedes-borne disease prevention.

Contributors

Both Henry Puerta-Guardo and Pablo Manrique-Saide read, edited, and approved the final version.

Declaration of interests

The authors declare no conflicts of interest.