The first question is whether the right endpoints are being studied. Contrary to prevailing assumptions (including those of a former Food and Drug Administration commissioner8), none of the vaccine trials are designed to detect a significant reduction in hospital admissions,

admission to intensive care, or death.9 Rather than studying severe disease, these mega-trials all set a primary endpoint of symptomatic covid-19 of essentially any severity: a laboratory positive result plus mild symptoms such as cough and fever count as outcome events (table )

These studies seem designed to answer the easiest question in the least amount of time, not the most clinically relevant questions.
Table 1 Details from the trial protocols for covid-19 vaccines3-6 View popupView inline
We shouldn’t be surprised.

Regulators not only agree with these endpoints but have prespecified the “success” criterion as 50% efficacy against the primary endpoint (with a confidence interval that includes efficacy as low as 30%).

10 Considering that these are relative risk reductions, absolute risk reduction will be important to assess once results are in, especially to assess benefit-risk profiles in healthy populations.