Respiratory Syncytial Virus (RSV) Activity and Palivizumab

RSV is a common virus which can cause serious illness in young children.

RSV season occurs in UT each year, usually between December and April. The COVID 19 pandemic and infection control measures implemented during the pandemic have changed the timing of these seasonal outbreaks. This has important consequences for when to start passive immunization with palivizumab for infants at very high-risk of hospitalization from RSV.

We define the start of the RSV season as 2 consecutive weeks with greater than 5% positivity of RSV tests in children. We have met these criteria as demonstrated in graphs below (2022-2023 season in blue).

Given passive immunization will provide the most benefit while high viral circulation is in communities, we recommend starting palivizumab prophylaxis now. We will continue to monitor RSV positivity rates. When rates decline to <10% positivity, we will re-evaluate the use of passive immunization.

R. Neal Davis MD MS
Sr. Medical Director
Pediatric Community Care
Intermountain Healthcare