The recent batch of COVID-19 vaccines distributed in the fall and winter has demonstrated a 54% effectiveness in preventing symptomatic infections among adults, as revealed by an early analysis from the Centers for Disease Control and Prevention (CDC). The study emphasized the vaccine’s ability to protect against the prevalent JN.1 subvariant.
This analysis was carried out through the CDC’s initiative, Increasing Community Access to Testing, providing free tests to uninsured individuals. Data collected from individuals experiencing COVID-19-like symptoms were gathered from tests conducted at CVS Pharmacy and Walgreens locations between September 2023 and January 2024.
Among the 9,222 tests eligible for analysis, the findings unveiled a 54% vaccine effectiveness among adults aged 18 and above. The report stated, “Updated monovalent COVID-19 vaccines provided 54% (95% CI = 46–60%) protection against symptomatic SARS-CoV-2 infection in persons recently vaccinated compared with those who did not receive an updated vaccine dose.” It’s noteworthy that the vaccines exhibited protection against infections caused by both the JN.1 and XBB-related lineages.
Although Pfizer, Moderna, and Novavax designed their updated vaccines to target the XBB.1.5 omicron subvariant, health officials were hopeful that the vaccines would remain effective against the dominant strains at the time of administration. Presently, the JN.1 omicron subvariant accounts for about 86% of COVID-19 infections in the U.S., according to recent federal surveillance data.
Acknowledging certain limitations, the report noted the potential for recall bias as patient history and infection data were self-reported. Additionally, the results were derived from a population opting for SARS-CoV-2 testing, introducing possible biases into the data.
