Healthy children born at term who did not have respiratory syncytial virus (RSV) infection as infants were at a considerably lower risk of developing asthma compared with infants with RSV infection, according to results of the INSPIRE study published in The Lancet.¹

In this multicenter study from the United States, researchers enrolled 1946 infants; of these 1741 children had data regarding RSV infection during the first year of life gathered through active and passive surveillance. The aim of the study was to ascertain if RSV infection during infancy was associated with childhood asthma. Their median age was 55 days; almost half (48%) of the study participants were girls.

A total of 944 (54%) of the 1741 participants with available RSV infection data had RSV infection during the first year of life. Over a follow-up period of 5 years, children who had had RSV infection during infancy had a significantly higher likelihood of developing asthma (21%) compared to those without RSV infection (16%). After adjusting for variables like sex, race and ethnicity, any breastfeeding, day-care attendance during infancy, exposure to second-hand smoke in utero or during early infancy, and maternal asthma, children who were not infected lowered their 5-year risk of current asthma by 26% with an adjusted risk ratio of 0.74. Children without RSV infection had lower probability of recurrent wheeze especially in the first two years of life. Researchers also noted that avoiding RSV infection during the first year of life could prevent 15% of 5-year current asthma cases.

This study has demonstrated an association between RSV infection during infancy and risk of development of childhood asthma. Since this was an observational study, the authors advocate further studies with long-term follow-up to conclusively establish a cause-and-effect association between the two.  

Reference

1. Rosas-Salazar C, et al. Respiratory syncytial virus infection during infancy and asthma during childhood in the USA (INSPIRE): a population-based, prospective birth cohort study. The Lancet. Published: April 19, 2023. DOI:https://doi.org/10.1016/S0140-6736(23)00811-5.