None of new drugs on trial will stop people dying, expert warns

VACCINES are being hailed as the solution to the Covid19 pandemic, but the trials currently under way are not designed to tell us if they will save lives, according to expert opinion in the British Medical Journal (BMJ) yesterday.

Peter Doshi, associate editor at the BMJ, said several trials are now in their most advanced phase three stage – but what will it mean exactly when a vaccine is declared “effective”?

Many may assume that successful phase three studies will mean there is a proven way of keeping people from getting very sick and dying from Covid-19, and a robust way to interrupt viral transmission, he said.

However, the phase-three trials are not actually set up to prove either.

“None of the trials currently under way 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,” Mr Doshi said.

He explained that all ongoing phase three 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.

However, Mr Doshi argued 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. Although Tal Zaks, chief medical officer at Moderna, told the BMJ their trial lacks adequate statistical power to assess that endpoint.

Part of the reason may be numbers, said Mr Doshi. Because most people with symptomatic Covid infections experience only mild symptoms, even trials involving 30,000 or more patients would turn up relatively few cases of severe disease.

“Hospitalisations and deaths from Covid-19 are simply too uncommon in the population being studied for an effective vaccine to demonstrate statistically significant differences in a trial of 30,000 people,” he said.