The circulation of influenza and several other respiratory viruses diminished during the pandemic in 2020; however, it was found to increase during the spring of 2021, noted researchers.

Flu activity was shown to reduce in March 2020, and continued to remain low until May 2021, as <0.4% of respiratory samples tested positive for influenza per week of the flu season. The patterns were similar for several other respiratory pathogens, including respiratory syncytial virus, parainfluenza viruses, and common human coronaviruses, reported researchers in Morbidity and Mortality Weekly Report. Human metapneumovirus and respiratory adenovirus were found to be circulating at low levels from 2020 to 2021. Rhinovirus and enterovirus were low till May 2020 before they rose to near pre-pandemic levels. Experts had warned of a COVID and flu ‘twindemic’ in the fall of 2020. However, from October 2020 to May 2021, circulating influenza had the lowest activity since 1997… (Medpage Today)