Kulldorff Claims 'Fatal Flaw' in Vaccine Study Design
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- Martin Kulldorff claimed to have identified 'the fatal flaw in test-negative designs' during a CDC 'Public Health Grand Rounds' seminar on measuring vaccine effectiveness.
- CDC's Carrie Reed, University of Michigan's Emily Martin, and Emory's Natalie Dean presented in-depth defenses of vaccine effectiveness study methods, rebutting Kulldorff's criticism.
- The test-negative design is a case-control study comparing vaccination rates between people who test positive for a specific pathogen (cases) and those who test negative (controls) among those seeking care for the same illness.
- CDC leadership blocked publication of its own staff's study on Covid vaccine effectiveness, citing 'concerns regarding the methodological approach to estimating vaccine effectiveness'; the paper was ultimately published in a peer-reviewed journal.
- HHS posted a new charter for the Advisory Committee on Immunization Practices (ACIP) that diminishes its role in evaluating vaccines and instead directs it to assess 'alternatives' to vaccination.
- Jay Bhattacharya, who is leading the agency though not officially acting director, framed the seminar series as reflecting CDC's commitment to excellence, collaboration, transparency, and intellectual honesty.
Why it matters: If the test-negative design is discredited, the U.S. loses one of its primary tools for monitoring real-time vaccine performance — including whether this season's flu shot is working or whether new vaccines like the RSV shot are performing as expected. The manufactured debate coincides with HHS's new ACIP charter that redirects the panel away from vaccine evaluation toward assessing 'alternatives' to vaccination.
