Key points:
- RSV infection in the first year of life is associated with an increased risk of asthma in children.
- According to the results, infants who did not contract RSV in the first year of life had a 26% lower risk of asthma at age 5.
- Researchers say they hope this motivates an increase in RSV prevention products, including vaccines.
A new observational study by Vanderbilt University Medical Center researchers has found that RSV infection in the first year of life is associated with a significantly increased risk of asthma in children. The study, published in The Lancet, is the first to look at the effects of RSV infections of all different severities on childhood asthma risk at a population level.
“For 60 years investigators have repeatedly identified the link between severe RSV and asthma; however, we’ve shown that this link is explained in part by shared heredity to both severe RSV and asthma,” said the study’s principal investigator and senior author Tina Hartert, director of the Center for Asthma and Environmental Sciences Research. “The solution in our study was to understand the link between RSV and asthma by ensuring all RSV infections would be captured using molecular techniques and post-season serology.”
The teams’ findings showed an age-dependent association between RSV infection during infancy and childhood asthma.
The INSPIRE (Infant Susceptibility to Pulmonary Infections and Asthma Following RSV Exposure) study included 1,946 healthy infants across Tennessee, ages 6 months or younger at the beginning of RSV season.
The researchers did biweekly surveillance and serology tests to classify infants as infected or not infected. According to the study, 54% of infants were infected with RSV in the first year of life, while 46% remained uninfected.
The infants were then followed annually and evaluated for asthma at 5 years old. Infants who weren’t infected with RSV in the first year of life had a 26% lower risk of asthma at age 5.
“We hope the results of this study motivate long-term follow-up of common respiratory outcomes among children in ongoing clinical trials of RSV prevention products, including vaccines and monoclonal antibodies that can decrease the severity of the infection,” said first author Christian Rosas-Salazar, MD, assistant professor of Pediatrics in the Division at Vanderbilt University Medical Center.