Grant: Project Grant

Respiratory Syncytial Virus (RSV) is a common seasonal virus that can cause severe lung infections in infants during the winter, often leading to hospitalizations. Babies under six months old are most at risk. Despite more than 60 years of research, we still don't have an effective vaccine against RSV, in part because we don't fully understand why young infants struggle to produce strong, protective immune responses when infected with RSV. Additionally, contracting RSV as an infant appears to increase the risk of asthma in childhood, but how early infection affects long-term health remains unclear. Our research team has been studying infant immune system development and RSV for many years. Most recently, we found that almost all infants contract RSV in their first winter. We also discovered specific immune "signals" that predict poor responses, suggesting that the age of infection plays a role in how well infants respond to RSV immunologically. Epidemiological studies in BC further indicate that younger babies may develop weaker immune responses to RSV during their first winter season. In this five-year study, we will follow a cohort of infants in British Columbia to examine how the timing of RSV infection affects their immunity and long-term childhood asthma risk. We will compare immune responses in infants exposed to RSV after six months of age to those exposed at younger (0-3 months) and older (4-6 months) ages to understand how early infection could lead to weaker immunity against the virus. We will identify key immune development changes that help babies build stronger defenses against RSV. Additionally, we will investigate how early RSV infection may increase asthma risk by following children up to age three and by comparing asthma rates in British Columbia before and during the pandemic. Our findings will help improve RSV prevention and vaccine programs in Canada, ultimately protecting young children and reducing future health risks.