
Severe respiratory syncytial virus (RSV) is a serious respiratory infection often affecting babies and children up to age 2. Now, a 2023 observational study by a team of researchers at Vanderbilt University Medical Center in Nashville confirms the oft-believed theory that an RSV infection in the first year of life may lead to childhood asthma.
RSV can lead to serious conditions, such as bronchiolitis, an inflammation of the small airways in the lung and pneumonia. In premature or very young babies, it can lead to serious illness and death, especially for those infants with chronic lung disease or congenital heart disease. According to Christian Rosas-Salazar, MD, MPH, the study’s first author and assistant professor of pediatrics at Vanderbilt University Medical Center, the study brought renewed attention to the connection between the two.
“We focused on the first year of life because we think the first year is a very important period of lung and immune development,” Dr. Rosas-Salazar said. “We believe that when a child is infected with RSV in the first year of life, when the lungs and immune system are still under development, that could lead to certain abnormalities that can later cause asthma.”
Often seasonal, RSV causes mild, cold-like symptoms, including fever, cough, wheezing, runny nose, sneezing and a decrease in appetite. The study, known as INSPIRE (Infant Susceptibility to Pulmonary Infections and Asthma Following RSV Exposure) included 1,946 eligible healthy infants who were 6 months old or younger at the start of Tennessee’s RSV season. That is typically November to March. Infants were recruited from 11 pediatric practices across Middle Tennessee and were screened through biweekly surveillance and serology tests for infected or not infected in the first year of life. Of the group, 54% of infants were infected with RSV in the first year of life; 46% were uninfected.
Followed annually, the study participants were evaluated for asthma at 5 years of age. Results showed infants who weren’t infected with RSV in the first year of life had a 26% lower risk of asthma at age 5. Researchers also believe that demonstrating the efficacy of RSV vaccines against childhood asthma might increase awareness and vaccination rates.
“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,” Dr. Rosas-Salazar said.