Witness Testimony

Christine Cotton, a biostatistician with more than two decades of experience in pharmaceutical clinical trials, testified regarding her review of Pfizer’s COVID-19 vaccine clinical trial documentation. She explained standard principles of good clinical practice and described how interim analyses with short follow-up periods were used to support early authorization. She argued that the primary efficacy endpoint—mild or moderate PCR-confirmed COVID-19—did not measure the full burden of disease and that alternative measures, such as antinucleocapsid serology, would have produced substantially lower efficacy estimates. She further stated that no statistically demonstrated efficacy was shown for severe cases or mortality in the authorization reports.
Cotton described what she characterized as statistical and methodological biases, including differential PCR testing frequency between study groups, allowance of symptom-suppressing medications, and lack of longer-term antibody measurements prior to authorization. She asserted that interim analyses at three months concealed declining neutralizing antibody levels that later justified booster doses. She also noted that several high-risk populations—including pregnant women, immunocompromised individuals, and those with comorbidities—were not adequately studied at the time of authorization, despite widespread rollout.
She raised concerns regarding trial data integrity, referencing reported site-level irregularities and the absence of comprehensive regulatory audits verifying source data. Cotton emphasized that authorizations are traditionally based on randomized clinical trial evidence rather than retrospective real-world database studies, which she described as methodologically weaker. She concluded that, in her assessment, the trial’s design, oversight, and reported results were inconsistent with established clinical research standards, thereby undermining the stated benefit-risk evaluation.