New research: Respiratory syncytial virus and the toll it takes on young children

“Our updated estimates reveal that children six months and younger are particularly vulnerable, especially with cases surging as Covid-19 restrictions are easing around the world and the majority of the young children born in the last two years have never been exposed to RSV (and therefore have no immunity against this virus). With numerous RSV vaccine candidates in the pipeline, our estimates by narrower age ranges help to identify groups that should be prioritised, including pregnant people..,” Harish Nair, University of Edinburgh and co-author, said in the report.

These findings are broadly consistent with previous estimates from a 2015 study, which placed the number of annual cases of RSV in children up to five years old at 3.3 crore, resulting in 1,18,200 overall deaths. In 2019, too, there were 3.3 crore RSV-associated acute lower respiratory infection episodes in children under five years old, leading to 26,300 in-hospital deaths, and 1,01,400 RSV-attributable deaths overall. This accounts for 2% of annual deaths from any cause in this age range.

For children under six months old, there were 66 lakh RSV-associated acute lower respiratory infection episodes globally in 2019, 13,300 hospital deaths, and 45,700 overall deaths attributable to RSV — 2.1% of annual deaths from any cause.

According to the report the incidence rate in India is 53 per 1,000 children per year (5.3%) and there were an approximate 61,86, 500 episodes of RSV-associated acute lower respiratory infection in children below five years.

Newsletter | Click to get the day’s best explainers in your inbox

Globally, only 26% RSV-associated deaths occur in a hospital. This is particularly apparent in low- and middle-income countries, where the in-hospital case-to-fatality ratio for children under five is 1.4%, compared to 0.1% in high-income countries. Overall, 97% of RSV deaths in children under five occurred in low- and middle-income countries.