While the country is dealing with massive waves of ‘Tri-demic’ where hospitals across the country are filing with children infected with three viruses [Influenza, Respiratory Syncytial Virus (RSV), and SARS-CoV-2], the recent reporting of hybrid virus particles (HVPs) from the coinfected human lung cells with influenza A virus (IAV) and RSV is highly worrisome. Scientists from the UK reported previously unknown interactions between IAV and RSV, two clinically important respiratory viruses that belong to different taxonomical families. IAV predominantly infects the upper and middle respiratory tract causing a generally mild flu, while RSV spreads more readily to the middle and lower respiratory tract (LRT). They provided evidence that coinfections can generate infectious HVPs composed of structural, genomic, and functional components of both parental viruses, enabling IAV to escape mucosal antibodies while spreading to the LRT, increasing the chances of influenza triggering a severe, and sometimes fatal, lung infection called viral pneumonia.
Although further research is required to better understand which virus combinations can generate infectious HVPs; which viral properties favor their formation; and how they impact pathogenesis and viral transmission, for now, scientists urge everyone to get vaccinated with available vaccines at the earliest, if not done so already.