Publication date: Dec 01, 2026
Children in the first months of life are at highest risk for Respiratory Syncytial Virus (RSV) bronchiolitis. Maternal specific anti-RSV IgG antibodies play a key role in preventing infection in early life. The COVID-19 pandemic changed the seasonality of RSV epidemics. We hypothesized that COVID-19 restrictions, affecting RSV circulation, altered RSV-specific immunity of pregnant women and their newborns. We compared anti-RSV IgM and IgG levels in maternal and cord blood (CB) samples collected from mother-newborn dyads at Policlinico Umberto I Hospital, Rome, Italy, across three consecutive RSV seasons: Group 1 (Nov 2020-Mar 2021; N: 24 dyads), Group 2 (Nov 2021-Mar 2022; N: 38 dyads), and Group 3 (Sep 2022-Mar 2023; N: 31 dyads). Median maternal anti-RSV IgM values were significantly higher in Group 3 (p = 0. 001) and in Group 2 (p = 0. 004) compared to Group 1. Anti-RSV IgG median values were significantly lower in Group 2 both in maternal (p = 0. 039) and CB (p = 0. 05) and in Group 3 in CB (p = 0. 029) compared to Group 1. These findings suggest that the COVID-19 pandemic caused an RSV-specific immunological debit in pregnant women and their infants, potentially explaining the altered RSV seasonality and increased bronchiolitis hospitalizations during 2021-2022.
Semantics
| Type | Source | Name |
|---|---|---|
| disease | MESH | COVID-19 pandemic |
| disease | MESH | bronchiolitis |
| drug | DRUGBANK | Palivizumab |
| disease | MESH | infection |
| disease | MESH | Viral bronchiolitis |
| disease | MESH | Pregnancy Complications Infectious |
| disease | MESH | Respiratory Syncytial Virus Infections |