Providence study sheds new light on the added benefit of COVID-19 boosters among vaccinated individuals

A Providence study released online today in the Journal of the American Medical Association sheds new light on the added benefit of a booster dose of a COVID-19 mRNA vaccine among previously vaccinated individuals.

Researchers found that boosters add about 70% extra protection, which lasts for 4-5 months, and concluded that booster vaccination is associated with significantly decreased odds of hospitalization for COVID-19 among fully vaccinated individuals. Odds of decreased hospitalization varied based on time since booster administration.

While previous studies have established the association between boosters and decreased risk of developing severe COVID-19 when compared with unvaccinated individuals, this study is unique in its focus on individuals who are already fully vaccinated with the primary series of an mRNA vaccine. It adds to the growing body of research around the effect of booster doses in various populations.

This research shows us that even if you're fully vaccinated, there's a real value to getting a booster. Compared to people who only had their initial vaccinations, people with boosters were a lot less likely to have severe Covid for 4-5 months after the booster shot."

Ari Robicsek, M.D., Providence's Chief Medical Analytics Officer and Study’s Senior Author

Providence, a not-for-profit health system serving the Western U.S., conducted the research at sites across six western states. It matched 3,052 cases hospitalized for COVID-19 within a Providence facility 4:1 with 12,248 controls admitted to a Providence facility non-electively for reasons other COVID-19. Cases were hospitalized between October 1, 2021, and July 26, 2022, and controls were admitted to a facility within three days in the same geographic location as their case and received a second vaccine within seven days of their case.

Journal reference:

Ridgway, J.P., et al. (2022) Odds of Hospitalization for COVID-19 After 3 vs 2 Doses of mRNA COVID-19 Vaccine by Time Since Booster Dose.


  1. Daniel O'Keefe Daniel O'Keefe United States says:

    This study was for folks over age 70. The headline should say this. Otherwise it deceives the public. We can suppose of course that these findings results would be less and less significant as the studied ages were lower. That matters to those interested in paying attention to public health policy.

    Please get better at directing your headlines to the actual topic, in this case, those over 70 and Their outcomes, especially weighted with co-morbidities. PLEASE.

    Thank you.

    From the study:

    There were 3062 cases (mean age, 70.8 [SD, 15.4] years; 52.6% were men; and 34.7% were boosted) and 12 248 matched controls (mean age, 67.1 [SD, 18.2] years; 46.7% were men; and 49.3% were boosted) included (Table). Factors associated with an increased odds of hospitalization for COVID-19 included age of 70 years or older, male sex, cognitive disease, chronic obstructive pulmonary disease, diabetes, immunodeficiency, obesity, rheumatologic disease, transplant, and BNT162b2 (Pfizer-BioNTech) vaccine."

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
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