Updated COVID vaccine linked to lower urgent care and hospitalization risk

Clinical takeaway: Adults can still gain meaningful protection from an updated COVID-19 vaccine, even if they have prior vaccination or infection history. Clinicians should continue recommending the 2025-2026 vaccine as a practical way to reduce medically attended COVID-19, especially for older adults and patients at higher risk for severe disease.

The 2025-2026 COVID-19 vaccines were associated with lower risk of emergency, urgent care, and hospital encounters for COVID-19 among immunocompetent adults, according to interim US data.

Many patients now have some combination of prior vaccination and infection, which can make the value of another updated vaccine dose less obvious in counseling conversations. In this analysis, the updated vaccine still provided additional protection beyond existing population immunity.

Researchers used VISION Network data from adults with COVID-like illness who sought emergency, urgent, or hospital care in seven US states from September through December 2025. Among emergency department and urgent care encounters, 2025-2026 vaccination was associated with 50% effectiveness against COVID-19–associated visits.

For hospitalizations, vaccine effectiveness was 55% against COVID-19–associated admission. Protection was similar in adults aged 65 years and older, with effectiveness of 48% against emergency or urgent care encounters and 53% against hospitalization.

The updated vaccines targeted JN.1-related SARS-CoV-2 variants, which were the main circulating strains during the study period. The authors noted that estimates reflect the added benefit of updated vaccination in a population with substantial prior infection-induced and vaccine-induced immunity.

The study did not evaluate children, immunocompromised adults, critical illness outcomes, or durability of protection over longer periods. Residual confounding and incomplete vaccination records may also affect vaccine effectiveness estimates.

In an accompanying invited commentary, Natalie Dean, PhD, of Emory Rollins School of Public Health, said the test-negative design remains useful for tracking vaccine effectiveness in real-world care. She noted that it is especially practical in the US, where vaccination, testing, and outcomes data are often spread across different systems.

For clinicians, these data can help address a common counseling question: whether an updated COVID-19 vaccine still matters for patients with prior immunity. The findings support continued vaccination discussions as SARS-CoV-2 lineages evolve and respiratory virus seasons remain unpredictable.

Source: Wiegand RE, et al. 2026 June 23. JAMA Netw Open. Interim estimated effectiveness of 2025-2026 COVID-19 vaccines in adults using a test-negative design