International changes in respiratory syncytial virus (RSV) epidemiology during the COVID‐19 pandemic: Association with school closures

Abstract

Background Little RSV activity was observed during the first expected RSV season since the COVID‐19 pandemic. Multiple countries later experienced out‐of‐season RSV resurgences, yet their association with non‐pharmaceutical interventions (NPIs) is unclear. This study aimed to describe the changes in RSV epidemiology during the COVID‐19 pandemic and to estimate the association between individual NPIs and the RSV resurgences. Methods RSV activity from Week (W)12‐2020 to W44‐2021 was compared with three pre‐pandemic seasons using RSV surveillance data from Brazil, Canada, Chile, France, Israel, Japan, South Africa, South Korea, Taiwan, the Netherlands and the United States. Changes in nine NPIs within 10 weeks before RSV resurgences were described. Associations between NPIs and RSV activity were assessed with linear mixed models. Adherence to NPIs was not taken into account. Results Average delay of the first RSV season during the COVID‐19 pandemic was 39 weeks (range: 13–88 weeks). Although the delay was <40 weeks in six countries, a missed RSV season was observed in Brazil, Chile, Japan, Canada and South Korea. School closures, workplace closures, and stay‐at‐home requirements were most commonly downgraded before an RSV resurgence. Reopening schools and lifting stay‐at‐home requirements were associated with increases of 1.31% (p = 0.04) and 2.27% (p = 0.06) in the deviation from expected RSV activity. Conclusion The first RSV season during the COVID‐19 pandemic was delayed in the 11 countries included. Reopening of schools was consistently associated with increased RSV activity. As NPIs were often changed concomitantly, the association between RSV activity and school closures may be partly attributed to other NPIs.

Burden of respiratory syncytial virus infection in older and high-risk adults: a systematic review and meta-analysis of the evidence from developed countries

“…A good surveillance system is especially important, since RSV circulation has been altered due to the COVID-19 pandemic. During 2020-2021, RSV season was either completely missed (Brazil, Chile, Japan, Canada and South Korea) or delayed by an average of 39 weeks due to the effect of the nonpharmacological contingency interventions (social isolation, movement and gathering restriction, school and workplace closing, face-mask policies) [44][45][46][47]. The virus resurged after restrictions were lifted and schools reopened [48].…”

Comparative analysis of the clinical and epidemiological characteristics of human influenza virus versus human respiratory syncytial virus versus human metapneumovirus infection in nine provinces of China during 2009−2021

“…With the relaxation of NPIs and waned immunity in young children may lead to the resurgence of respiratory virus infection, and even lead to larger or more severe outbreaks, especially in children. 40,41…”

“…Reicherz et al 39 have found that HRSV antibody levels and neutralization were reduced in women and infants 1 year into the COVID‐19 pandemic compared to earlier in the pandemic. With the relaxation of NPIs and waned immunity in young children may lead to the resurgence of respiratory virus infection, and even lead to larger or more severe outbreaks, especially in children 40,41 . Therefore, ongoing surveillance for HIFV, HRSV, HMPV, and other respiratory viruses is important during and after the COVID‐19 pandemic.…”

Impact of COVID-19 Pandemic and Lockdown on the Epidemiology of RSV-Mediated Bronchiolitis: Experience from Our Centre

“…A trend in delayed or missed RSV epidemics was observed worldwide after the first COVID-19 pandemic wave, and school re-opening was one of the non-pharmaceutical interventions associated with increased RSV circulation [ 20 ]. Contrary to this other than our results, France reported an RSV epidemic during the winter 2020–2021, just after the end of the lockdown.…”