Validating full safety of vaccines might take months but effectiveness judgements likely soon

Print Friendly, PDF & Email
Credit: Getty Images
Credit: Getty Images

The global campaign to identify effective vaccines against COVID-19 has entered the final stage of testing for regulatory approval—Phase III trials—for several promising candidates. Evaluation will be guided by criteria established by the Food and Drug Administration and the World Health Organization.

The minimum threshold for efficacy is observed reduction of disease incidence of at least 50 percent, with high statistical confidence of efficacy above a minimum of 30 percent. Full safety reviews of the vaccine candidates may take several months, to ensure any adverse events are given sufficient time to become evident and then studied.

Follow the latest news and policy debates on agricultural biotech and biomedicine? Subscribe to our newsletter.

For efficacy, however, statistically valid determinations can be made after approximately 150 confirmed cases of COVID-19 among trial participants, which may occur relatively quickly given the prevalence of the virus in many communities. Consequently, on the question of whether a vaccine works to prevent progression from the virus to the disease, a clear signal is likely to occur in a few months after the trial begins rather than over the longer time frames that may be necessary for evaluation of their safety profiles.

Related article:  Going forward, taming COVID may depend more on logistics and administration than science

Read the full report here (PDF)

Outbreak Featured
Infographic: Autoimmune diseases — 76 identified so far — tend to target women over men. Here is a master list

Infographic: Autoimmune diseases — 76 identified so far — tend to target women over men. Here is a master list

There are many autoimmune diseases, and taken together they affect as much as 4.5 percent of the world’s population. This ...
Are GMOs and pesticides threatening bees?

Are GMOs and pesticides threatening bees?

First introduced in 1995, neonicotinoids ...
glp menu logo outlined

Newsletter Subscription

* indicates required
Email Lists
glp menu logo outlined

Get news on human & agricultural genetics and biotechnology delivered to your inbox.