Mutism on pause in Johnson & Johnson 1:35 trials
(CNN) -
The most advanced coronavirus vaccine trials can't tell researchers whether inoculations will save lives, or even prevent serious illness, a drug development expert noted Wednesday.
The ongoing trials are only designed to show whether vaccines prevent infection, and most infections are mild infections, said Peter Doshi, associate editor of the BMJ medical journal and Drug Development specialist at the Faculty of Pharmacy at the University of Maryland.
"I think there are some pretty general assumptions about what we're getting from phase 3 studies" of vaccines, Doshi told CNN.
'None of the trials currently underway are designed to detect a reduction in any serious outcome, such as hospital admissions, intensive care use or deaths.
Nor are vaccines being studied to determine if they can interrupt transmission of the virus, "Doshi wrote in the medical journal BMJ.
'Hospital admissions and deaths from COVID-19 are simply too rare in the population being studied for an effective vaccine to demonstrate statistically significant differences in a trial of 30,000 people.
The same is true of its ability to save lives or prevent transmission - trials are not designed to find out. '
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Vaccines that are in phase 3
Four vaccines being developed in the United States are in the most advanced stage of development of phase 3: those being made by Moderna, Pfizer, AstraZeneca and Johnson & Johnson.
They are 'event-driven' trials, meaning the goal is to keep them running until a certain number of volunteers are infected.
If more infections are seen among people who received placebo or sham injections, it is an indication that the vaccines prevented infection.
But that doesn't mean the vaccines saved people from serious illness or death, Doshi argued.
"A serious illness requiring hospital admission, which occurs in only a small fraction of symptomatic COVID-19 cases, is unlikely to occur in significant numbers in trials," he wrote.
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The U.S. Food and Drug Administration's (FDA) Vaccine and Related Biologicals Advisory Committee is meeting Thursday to discuss ongoing coronavirus vaccine trials and what members would like that FDA considers when reviewing any request for an emergency use authorization for a vaccine or full approval.
Doshi said they should consider asking companies to reconfigure their trials to include data on preventing serious illness and death.
"People are hoping that the worst part of the covid iceberg - ICU admissions, hospitalizations and deaths - is what would end up with a vaccine," he said.
But current trials will only look for early infections.
These trials can be kept current and added to eventually answer the question of whether covid vaccines save lives and prevent serious disease.
"The tests are ongoing," he told CNN.
There is a possibility of that.
It's not too late".
Coronavirus Vaccine