None of the current COVID-19 vaccine trials are designed to detect a reduction in any serious outcome such as hospitalisations, intensive care use, or deaths. Here’s why COVID-19 vaccine trials cannot tell us if the vaccines will save lives.
Vaccines are being hailed as the solution to the covid-19 pandemic, but the vaccine trials are not designed to tell us if they will save lives, reports Peter Doshi, Associate Editor at The BMJ (read full report below).
Many may assume that successful phase 3 studies mean we have a proven way of keeping people from getting very sick and dying from covid-19. And a robust way to interrupt viral transmission.
Yet the phase 3 trials are not actually set up to prove either, says Doshi.
“None of the trials currently underway are designed to detect a reduction in any serious outcome such as hospitalisations, intensive care use, or deaths. Nor are the vaccines being studied to determine whether they can interrupt transmission of the virus,” he writes.
He explains that all ongoing phase 3 trials for which details have been released are evaluating mild, not severe, disease – and they will be able to report final results once around 150 participants develop symptoms.
In Pfizer and Moderna’s trials, for example, individuals with only a cough and positive lab test would bring those trials one event closer to their completion.
Yet Doshi argues that vaccine manufacturers have done little to dispel the notion that severe covid-19 was what was being assessed.
Moderna, for example, called hospitalisations a “key secondary endpoint” in statements to the media. But Tal Zaks, Chief Medical Officer at Moderna, told The BMJ that their trial lacks adequate statistical power to assess that endpoint.
Part of the reason may be numbers, says Doshi. Because most people
with symptomatic covid-19 infections experience only mild symptoms, even
trials involving 30,000 or more patients would turn up relatively few
cases of severe disease. ... Continue reading >>>