Infectious Disease expert injects word of caution over COVID-19 trial vaccine

SANTA BARBARA, Calif. - A word of caution following Pfizer's announcement Monday about an experimental COVID-19 vaccine, courtesy of a local infectious disease expert.

“Very encouraging but doesn't give a full picture of how long the protection may last,” said Dr. David Fisk, an Infectious Disease expert with Cottage Health and Sansum Clinic. “Does it trail off after a few weeks or months and if so, how much?”

The first Emergency Release of the trial vaccine includes up to 10,000 doses for Vandenberg Air Force Base (VAFB) within the next month, on a voluntary basis. However, VAFB military participants are advised to do their own research to determine if the benefits outweigh the risks.

Fisk said while this is exciting news -- a trial vaccine touted as having a 90% efficacy rate -- the “critical missing piece of this puzzle" is about safety.

It is a point he stressed ahead of an approved vaccine being available to the general public. 

“Right now, it is so vitally important that any COVID vaccine that comes out be safe because it's going to be used so widely in a wide range of individuals, some of who were previously healthy at the time they received the vaccine,” said Fisk. 

The Food and Drug Administration (FDA) wants Pfizer to track at least half of its study volunteers for two months for side effects before coming up for review.

“Most vaccine side effects that happen, happen immediately or shortly after the vaccine is administered,” said Fisk. “But certainly there are plans for looking for side effects of any vaccine that's approved, for two years after its initial Emergency Release and approval." 

Fisk said the fact that Pfizer's vaccine announcement came from a "company media report" rather than a scientific study makes him and others especially cautious.

He added that once a COVID-19 vaccine is approved, doctors will likely have to order large quantities -- perhaps a minimum of 1,000 at a time -- and administer the vaccine in a large setting. He also admitted that will be a tremendous challenge.

"This is a vaccine that is gonna be logistically very, very hard to deliver to large numbers of people because it has to be stored at 70 degrees below zero celsius temperature with special types of freezers. It's very unstable when you take it out of the freezer and it sits on a shelf and only lasts for two hours and it's inactive. And many other challenges with the way that it has to be managed and protected before it's actually provided to someone as a shot.”

California has set up a Safety Review Committee and partnered with Oregon and Washington as an added layer of safety for these vaccine trials. 

“I’m certainly much more optimistic that we'll see at least some of this vaccine in our community in the next six months than I was a week ago.”