Effectiveness of the 2023-to-2024 XBB.1.5 COVID-19 Vaccines Over Long-Term Follow-up: A Target Trial Emulation

URL

https://www.acpjournals.org/doi/10.7326/ANNALS-24-01015

Authors

George N. Ioannou, Kristin Berry, Nallakkandi Rajeevan, Yuli Li, Lei Yan, Yuan Huang, Hung-Mo Lin, David Bui, Denise M. Hynes, Mazhgan Rowneki, Amy Bohnert, Edward J. Boyko, Theodore J. Iwashyna, Matthew L. Maciejewski, Valerie A. Smith, Theodore S. Z. Berkowitz, Ann M. O'Hare, Elizabeth M. Viglianti, Mihaela Aslan, and Kristina L. Bajema

Published Date

February 4, 2025

Publication

Annals of Internal Medicine

Organization

Veterans Affairs Puget Sound Health Care System

Description

This large cohort study evaluated the effectiveness of the monovalent COVID-19 vaccines from Pfizer–BioNTech and Moderna targeting the XBB.1.5 variant of Omicron. Among more than half a million matched pairs, the vaccines showed no measurable protection against documented SARS-CoV-2 infection, with an estimated vaccine effectiveness of –3.3%. Effectiveness against hospitalization related to COVID-19 was 16.6%, and effectiveness against COVID-19–related death was 26.6%. The authors noted that any initial benefits declined over time, indicating limited and waning protection from this updated vaccine formulation.

Format

document

Topics

breakthrough cases,COVID-19,vaccines