How to evaluate a coronavirus vaccine


Several large-scale vaccine trials are underway in the U.S. and have moved into phase three. If any of the trials have favorable results after this phase, vaccine developers could begin applying for approval from the FDA to release it to the public.

“The data will be released, the question is when,” said Ali Moghtaderi, professor of public health and management at George Washington University. He says that while companies usually keep data confidential until the phase three trials are completed, because of the heavy public interest in a coronavirus vaccine, some of the data has already been released.

Moderna and Pfizer have already released details about how their studies are designed, including how the vaccine is being tested, the metrics they are using to determine success and the demographics of the participants.

The key factors, according to Moghtaderi, are efficacy and safety. But those metrics are not as straightforward as they may seem.

For example, data around the safety of the vaccine may be incomplete if the study is not tested on a wide range of people, as different groups can face varying side effects.

Another sticking point that came out after Moderna and Pfizer revealed their study designs was how the companies were measuring cases.

“Some very useful comments and suggestions came out from the scientific community with respect to how we count an infection,” explained Moghtaderi. “Since most of the COVID-19 cases are actually mild, that may be a mixed reading.”

A vaccine that can prevent mild cases but not moderate to severe cases will not have as much value to the public.

This is why he says an independent body of scientists should come together to review data from the phase three trials and advise the public about safety and efficacy, and whether or not some individuals may face more severe side effects.