Note that views expressed in this opinion article are the writer’s personal views and not necessarily those of TrialSite.
A commentary published on Medscape.com, April 29, 2021, claims that COVID-19 vaccine clinical trials were too brief to judge outcomes using absolute risk reductions (ARR), and that extending a clinical trial’s length of time can increase the ARR, thereby reducing the number needed to vaccinate to prevent one infection. Why Number Needed to Treat Can Be Misleading for Vaccines (medscape.com). The author’s argument in the commentary may be technically correct under certain assumed conditions or considered “contextual points,” but the argument is clinically meaningless at best.
The Pfzier/BioNTech vaccine’s absolute risk reduction is 0.7%, and the vaccine efficacy or relative risk reduction (RRR) is 95.1% Medicina | Free Full-Text | Outcome Reporting Bias in COVID-19 mRNA Vaccine Clinical Trials (mdpi.com). Published results from the Pfzier/BioNTech phase 3 clinical trial covered the period from May 2020 to November 2020, having a trial length of 6-7 months; more than just “a few weeks” claimed by the Medscape.com commentary. Inside the Pfizer/BioNTech COVID...
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