Vaccine trial tutorial

Trump’s comments about rushing out a COVID-19 vaccine before election day (which is fatuous propaganda) seem to have sown concern about any vaccines that do emerge. The reason there will be no vaccine available to the general public before the election, or even before spring of 2021 at the very earliest, is because of the extensive testing required before any vaccine is ready. I’m in the Moderna trial, so I’ll reference that, although there are other trials either in phase III or slated to launch into phase III, both here and abroad, using a variety of approaches.

Testing means first testing in animal models. The Moderna mRNA vaccine proved safe and efficacious (protected against a challenge infection) in animal models. After that, there are three phases of clinical trials in humans. Phase I is for safety. If the vaccine passes the safety trial, it goes in Phase II, which is a small-scale trial for efficacy. In this case, efficacy means does it elicit an immune response (human challenge trials for SARS-CoV-2 would be unethical). The Moderna vaccine has passed Phases I and II and is now enrolling in Phase III. I volunteered for the Phase III trial, which is targeted to enroll 30,000 and lasts two years. If early results look promising, it is possible that it could be approved by next year before the scheduled end of the Phase III trial. The US government has already purchased several tens of millions of units, so distribution can happen almost immediately once approved.

Although the Moderna trial isn't a challenge trial, based on an enrollment of 30,000 and a two-year study period, it is certain that a significant number of folks in both arms will be infected and they will be followed for severity of infection to see if the vaccine proves a benefit over the placebo.

Dr. Fauci is correct, a vaccine won't be ready for the general public for nine months or more. Ready means not only safe but also effective. It does no good to vaccinate millions of people with something that is safe but provides no significant and durable protection from the virus.