Pandemic changed patterns
This research was completed before the COVID-19 pandemic, and it is not yet known how that could affect RSV disease burden long term.
However, Dr. Hartert said, RSV circulation has been significantly changed during the pandemic, both in intensity and timing, likely because of a combination of COVID and the public health preventive measures.
“As people return to normal activities and the public health measures put in place to stop the spread of COVID are eased, we are likely to see increases in circulation of RSV and return to its circulation during the winter months – typically similar to circulation of flu – from November through March in temperate climates in the northern hemisphere,” she said.
A coauthor of the paper, Harish Nair, PhD, with the Centre for Global Health, Usher Institute, University of Edinburgh, said in a press release that their findings have particular significance as COVID restrictions ease around the globe.
“The majority of the young children born in the last 2 years have never been exposed to RSV (and therefore have no immunity against this virus),” Nair wrote.
Most deaths occurring outside hospitals
A challenge in reducing the deaths in those 5 years old and younger is that most (76%) of deaths are happening in the community outside hospitals.
The authors wrote: “For every RSV-associated acute lower respiratory infection in-hospital death, we estimate approximately three more deaths attributable to RSV in the community.”
The percentage dying outside hospitals is even larger (81%) in low- to middle-income countries.
This work built on a previous review by the team that analyzed 317 studies. They updated their search with 113 new eligible studies and unpublished data from 51 papers published between Jan. 1, 2017, and Dec. 31, 2020.
The authors acknowledged some limitations, including variations in study settings and in definitions for acute lower respiratory infection, healthcare access, and eligibility for RSV testing.
The study was funded by EU Innovative Medicines Initiative Respiratory Syncytial Virus Consortium in Europe. Dr. Li reported grants from Wellcome Trust and the World Health Organization outside the submitted work. Dr. Hartert, Dr. Ortiz, and Dr. Nair disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.