Table 1.

Comparison of characteristics of severe acute respiratory syndrome coronavirus 2, influenza, and respiratory syncytial virus

	SARS-CoV-2	Influenza	RSV
Viral structure	Single-stranded, positive-sense RNA	Negative-sense, single-stranded RNA with surface glycoproteins integral in determining influenza type	Filamentous enveloped, negative-sense, single-stranded RNA
Zoonotic infection	Bats	Avian and swine	Animal models of RSV infections in rodents and nonhumans primates
Virulence	Median r0 2.79	Median r0 1.28	Median r0 1.2–.2.1
Population at risk	•Hypertension •Diabetes •Smoking history •Age: elderly •Male sex •Pregnancy •Obesity •History of heart disease •History of lung disease	•History of chronic disease •Neuromuscular disorders •Morbid obesity •Pregnancy •Age: elderly and young children	•Age: children and elderly •History of heart disease •History of lung disease
Time until postexposure presentation	3–7 d	2–5 d	4–6 d
Clinical symptoms	•Fever •Headache •Dyspnea •Cough •Myalgias •Fatigue •Anosmia and loss of taste May be asymptomatic	•Fever •Nasal congestion •Sore throat •Myalgias •Fatigue •Nausea?, vomiting •Abdominal pain •Diarrhea	•Fever •Poor appetite •Rhinorrhea •Cough •Dyspnea •Wheezing
Duration of symptoms	Depends on severity of illness	Typically resolves by day 8	Typically resolves by 3–7 d
Complications	Post-COVID syndrome and severe cases can lead to ARDS	Severe cases can lead to ARDS	Severe cases can lead to bronchiolitis and pneumonia (especially in pediatric cases)

Abbreviation: ARDS, acute respiratory distress syndrome.

Data regarding SARS-CoV-2 from Refs.44, 45, 46, 47, 48, 49, 50, 51, 52, 53; data regarding influenza from Refs.54, 55, 56, 57, 58; data regarding RSV from Refs.59, 60, 61