Viral interference – the influence of one virus on infection by another virus – is important in understanding respiratory viral circulation and the impact of vaccines.

Tina Hartert, MD, MPH, visiting student Niek Achten, and colleagues, studied viral interference between respiratory syncytial virus (RSV) and human rhinovirus (HRV), the most common viruses associated with acute respiratory tract infections in infants.

The investigators evaluated cases of RSV and HRV in three populations of infants. They found that the risk of HRV infection was lower in RSV–infected infants in all groups. In a randomized population, infants who were administered RSV immunoprophylaxis to prevent RSV infection were more likely to have HRV infection.

The findings, reported in the Journal of Infectious Diseases, demonstrate a reduced risk of HRV when infected with RSV. The association was consistent across three distinct populations of infants spanning a decade of study, different geographical regions and varying disease severity.

The phenomenon of RSV–HRV interference may influence vaccine development and prevention strategies for viral respiratory tract infections in infants.