COVID-19 Vaccine Effectiveness Study Finally Published

A study analyzing the effectiveness of COVID-19 vaccines has been published after initial blockage from being featured in a government health journal. According to findings released by JAMA Network Open, the vaccine shows a 55% effectiveness against COVID-19-related hospitalizations and cuts emergency department and urgent care visits by 50%.

These results align with prior research confirming vaccine efficacy. However, political appointees from the Trump administration previously withheld the study from appearing in a Centers for Disease Control and Prevention (CDC) publication, citing concerns about the study’s methodology and potential for flawed results due to false assumptions.

Despite these concerns, many public health experts defend the study’s design, asserting its reliability. Natalie Dean, an Emory University biostatistics expert, emphasized the necessity of documenting vaccine effectiveness amid evolving viral strains in a related commentary at the study’s publishing.

“It is critical that we continue to characterize and publish estimates of vaccine effectiveness in populations with changing immunity against evolving viral strains,” Dean wrote.

The study was initially slated for publication in Morbidity and Mortality Weekly Report, the CDC’s primary publication, but was halted by Jay Bhattacharya, the acting director at the time. Althea Grant-Lenzy, CDC’s chief science officer, clarified that this decision merely postponed the publication as the authors addressed concerns and opted for other journal submissions.

The study utilized the “test-negative design,” examining patients admitted with respiratory illnesses. Researchers assessed vaccination status and determined the likelihood of a positive COVID-19 diagnosis in vaccinated versus unvaccinated individuals. This design has been validated by its use in reputable journals, including Pediatrics and the New England Journal of Medicine.

Bhattacharya expressed skepticism over the methodology due to its reliance on certain assumptions. He noted potential bias from factors like prior infections and patient behavior patterns. In response, supporters believe the design effectively adjusts for these variables, considering widespread prior infections in the population.

Although no study design is perfect, U.S. Department of Health and Human Services officials have yet to propose a viable alternative for real-time vaccine efficacy assessment. The CDC convened a forum earlier this month to debate the merits of such studies, featuring varied panel views. Renowned biostatistician Martin Kulldorff joined the discussion, critiquing the inclusion of patients with differing diseases and questioning the lack of long-term evaluation studies.

Audience members reminded the panel of the urgent circumstances during the pandemic, prompting reliance on the study design for timely results.

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