(HealthDay News) — The 2023 to 2024 COVID-19 vaccine provided additional effectiveness against medically attended COVID-19, according to a study published online June 24 in JAMA Network Open.

Ruth Link-Gelles, PhD, MPH, from the US Centers for Disease Control and Prevention in Atlanta, and colleagues conducted a case-control study to examine the vaccine effectiveness (VE) of 2023 to 2024 (monovalent XBB.1.5) COVID-19 vaccines against COVID-19-associated emergency department (ED) and urgent care (UC) encounters, hospitalizations and critical illness among adults during periods of Omicron XBB and JN.1 predominance.

The researchers found that 37,096 (11%) of 345,639 eligible ED and UC encounters in immunocompetent adults with COVID-19-like illness and available test results had a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) result. During seven to 299 days after vaccination, VE against COVID-19-associated ED and UC encounters was 24%. Nine percent of 111,931 eligible hospitalizations in immunocompetent adults with COVID-19-like illness and available test results had a positive SARS-CoV-2 test result. VE was 29 and 48% against COVID-19-associated hospitalization and critical illness, respectively, during seven to 299 days after vaccination. VE was highest at seven to 59 days after vaccination (VE: 49, 51 and 68% against ED and UC encounters, hospitalizations and critical illness, respectively) and then waned (VE at 180 to 299 days after vaccination, −7, −4 and 16%, respectively).

“The 2023-2024 COVID-19 vaccines were associated with additional protection against COVID-19-associated ED and UC encounters, hospitalization, and critical illness beyond existing protection provided by prior vaccination or SARS-CoV-2 infection,” the authors write.

Several authors disclosed ties to the pharmaceutical industry.

Abstract/Full Text