We conducted the Respiratory Syncytial Virus (RSV) Prevention Phase II study to help us better understand if preventing RSV in infancy can reduce asthma in childhood. Respiratory syncytial virus (RSV) is the most important viral cause of lower respiratory tract infections (LRTI), like bronchiolitis and pneumonia, in children worldwide.
About RSV
RSV infections generally occur in the fall, winter and spring. While most infants experience RSV infection during their first year of life, nearly all children will get RSV by the time they are two years old. In older children and young adults, RSV most often causes a cough or cold-like symptoms, but in infants, especially those younger than six months old, RSV infection can be more serious. It can cause pneumonia or inflammation of the airways, which may require hospitalization. American Indian and Alaska Native (AI/AN) infants are at increased risk of severe RSV compared to infants across the US. 10% of Native American infants in the Southwest are hospitalized with RSV infections each year.
RSV disease in infancy can have lasting effects. Infants who experience severe RSV often continue to have breathing trouble or wheezing during the first few years of their life. Children who have severe RSV as babies are more likely to have asthma when they are older, but there are many things about the relationship between RSV and asthma that are not fully understood.
RSV Prevention
Researchers have been working on vaccines to prevent RSV for more than 50 years, but none are available yet. From 2004 to 2010, the CIH helped evaluate a different method of preventing disease with a monoclonal antibody called motavizumab. Monoclonal antibodies are similar to vaccines, and can be given via injection to newborns to protect them when they are at greatest risk of complications from RSV LRTI.
Motavizumab was evaluated in more than 2,000 healthy, full term infants, and it reduced RSV-associated hospitalization by 87% in the babies who received it. The infants who participated in this study are now between 10 and 14 years old. We re-contacted families of these children and invited them to participate in a brief follow up study called RSV prevention part II. With the consent of the parent or guardian, we administered a questionnaire to understand the child’s breathing and health, and well as reviewed their medical records to determine if they had asthma. This helped us better understand the relationships between RSV in infancy and asthma in childhood. This study provided important information for Navajo and White Mountain Apache communities in the Southwest, and helped build our understanding of the impact of RSV around the world.
This study was funded by The Bill and Melinda Gates Foundation