Respiratory and Other Infections Following COVID

One hypothesis for the respiratory syncytial virus (RSV) surge in 2022 was suppression of immune responses following SARS-CoV-2 infection. Our objective was to compare the risk of subsequent RSV and other infections among children with and without SARS-CoV-2 infection.

We conducted a retrospective cohort study using electronic health record data from 27 US health systems analyzing children aged under 5 years with SARS-CoV-2 infection (test/coded) between March and July 2022. The comparison groups were children with (a) influenza infection and (b) respiratory tract infection with no evidence of SARS-CoV-2/influenza infection. The primary and secondary outcomes were RSV infection and respiratory or any infection in the subsequent 15 to 180 days, respectively. We applied inverse probability of treatment weighting and performed weighted logistic regression modeling.

Our primary and secondary cohorts consisted of 18 767 and 114 414 children with SARS-CoV-2 infection, and 6697 and 30 424 with influenza infection, respectively, and 46 697 with another acute respiratory tract infection. The odds of subsequent RSV were lower in the SARS-CoV-2 group compared with the influenza group (adjusted odds ratio [aOR] 0.73, 95% CI 0.61-0.86) and compared with the group with any respiratory tract infection (aOR 0.78, 95% CI 0.7-0.87). The odds of a respiratory tract infection and any infection were lower in the SARS-CoV-2 group than the influenza group (aOR 0.62, 95% CI 0.59-0.64 and aOR 0.67, 95% CI 0.65-0.7, respectively).

We did not find an increased risk of RSV or a respiratory or any type of infection within 6 months of SARS-CoV-2 infection, compared with influenza and other respiratory illnesses.