Randomized controlled trials of vaccines
A list of 339 and still counting
“The only vaccine that has been tested in a full-blown placebo trial against an inert placebo was the Covid vaccine,” Kennedy said on May 14. “The other 76 vaccines that children in this country receive from birth to 18 years old have not been safety-tested in prelicensing studies against a placebo, which implies we lack an understanding of the risk profiles for those products, and I aim to address that.”—CNN
Hmmm. Is this a true statement? A recent article on the CIDRAP website described a project led by Dr. Jake Scott, a Stanford infectious disease physician, who is compiling a spreadsheet of all the randomized trials ever conducted for licensed vaccines, with control groups that received either saline or an “inert” placebo. The spreadsheet can be found here on the website of Dr. Scott’s colleague, Dr. Brad Spellberg. The list of randomized clinical trials with saline or inert placebo control is still growing, but today stands at 339. Scott believes that eventually the list will grow to more than 400, as he and his colleagues continue to review the literature and add to the list. The spreadsheet describes efficacy and safety data.
Influenza vaccines and certain COVID vaccines that undergo modification on an annual basis do not undergo new randomized clinical trials every year. Once the influenza or COVID vaccine platform (e.g., inactivated, live attenuated, recombinant) is licensed, the vaccines can be modified periodically to account for antigenic drift in the viruses, as long as all of the other vaccine characteristics are unchanged. Conducting large-scale randomized controlled trials annually for these vaccines would be logistically nearly impossible, given the time constraints imposed by selecting the antigenic variants, conducting trials and manufacturing large amounts of vaccine. In addition, there are ethical issues concerning administration of placebo to subjects when the vaccine has already been proven to be effective. The effectiveness and safety of these updated vaccines is assessed nevertheless, but by using observational studies rather than randomized clinical trials.