More vaccines on the horizon
The panel also heard an update from drug company AstraZeneca on its vaccine. It’s being used in 18 countries but has not yet been authorized in the United States.
That vaccine is currently in phase 3 of its U.S. clinical trials, and more than 26,000 people who have volunteered to get the shot had received their second dose as of Jan. 21, the company said.
The Food and Drug Administration requires at least 2 months of follow-up before it will evaluate a vaccine for an emergency-use authorization, which means the company would be ready to submit by the end of March, with a possible approval by April.
The AstraZeneca vaccine uses a more traditional method to create immunity, slipping a key part of the virus that causes COVID-19 into the shell of an adenovirus – a virus that causes cold-like symptoms – that normally infects monkeys. When the immune system sees the virus, it generates protective defenses against it.
The two-dose vaccine can be stored in a regular refrigerator for up to 6 months, which makes it easier to handle than the mRNA vaccines, which require much colder storage. Another advantage appears to be that it’s less likely to trigger severe allergic reactions. So far, there have been no cases of anaphylaxis reported after this shot.
In total, four serious side effects have been reported with the AstraZeneca vaccine, including two cases of transverse myelitis, a serious condition that causes swelling of the spinal cord, leading to pain, muscle weakness, and paralysis. One of these was in the group that got the placebo. The reports paused the trial, but it was allowed to continue after a safety review.
This vaccine also appears to be less effective than the mRNA shots. Data presented to the panel show it appears to cut the risk of developing a COVID infection that has symptoms by 62%. That’s over the 50% threshold the FDA set for approval but less than seen with the mRNA vaccines, which are more than 90% effective at preventing infections.
“Is the average person going to want to take the AstraZeneca shot? What role is this going to play in our vaccination program?” Dr. Schaffner said.
Johnson & Johnson will have enough data from its clinical trials to submit it to the FDA within the next week, the company said in a call with shareholders on Tuesday. So far, its one-dose shots looks to be about as effective as both the Pfizer and Moderna vaccines.
“It could be that we wind up with four vaccines: Three that can run very fast, and one that’s not so fast,” Dr. Schaffner said.
A version of this article first appeared on Medscape.com.