Respiratory virus circulation during pandemic: Why were some viruses still circulating?

Area of Science:

• Virology
• Epidemiology
• Public Health

Background:

• The COVID-19 pandemic prompted global adoption of non-pharmacological interventions (NPIs).
• NPIs aimed to curb SARS-CoV-2 transmission but also affected other respiratory viruses.
• Understanding these differential impacts is crucial for public health strategies.

Purpose of the Study:

• To review and discuss data on the circulation of major respiratory viruses during the COVID-19 pandemic.
• To explore factors influencing the varied circulation patterns of different respiratory viruses.
• To investigate the sustained prevalence of human rhinovirus (HRV) during the pandemic.

Main Methods:

• Literature review of published studies on respiratory virus circulation during the COVID-19 pandemic.
• Analysis of reported detection rates for various respiratory viruses, including influenza, RSV, hCoVs, HPIVs, hMPV, adenovirus, and HRV.
• Synthesis of hypotheses explaining observed viral transmission dynamics.

Main Results:

• Significant declines were reported for enveloped viruses like influenza, RSV, hCoVs, HPIVs, and hMPV.
• Non-enveloped viruses, notably adenovirus and human rhinovirus (HRV), demonstrated less substantial decreases in circulation.
• HRV exhibited particularly high and sustained prevalence throughout the pandemic years.

Conclusions:

• NPIs and behavioral changes differentially impacted respiratory virus circulation based on viral characteristics.
• Viral envelope presence and transmission modes likely influenced susceptibility to NPIs.
• The resilience of HRV warrants further research into its transmission dynamics and potential for viral interference.