A panel of advisers to the Food and Drug Administration (FDA) voted on Thursday to endorse for emergency use a COVID-19 vaccine from Moderna and the National Institutes of Health.
The advisers voted 20-0 with one abstention, in agreement that the benefits of the vaccine outweighed its risks in people aged 18 and older. The vote came after seven hours of debate over technical details of the company’s study and follow-up plans.
The FDA is expected to authorize the latest Moderna vaccine quickly, after which Moderna is set to start distribution of millions of doses, intended first for health workers and those relatively more vulnerable such as nursing home residents and staff.
"To go from having a [genetic] sequence of a virus in January to having two vaccines available in December is a remarkable achievement," said Dr. James Hildreth, chief executive of Meharry Medical College, who voted to recommend the vaccine for emergency use.
The one abstention came from Dr. Michael Kurilla, who works at the National Institutes of Health and felt blanket authorization for those 18 and older was too broad.
"I'm not convinced that for all of those age groups the benefits do actually outweigh the risk. And I would prefer to see it more targeted towards people at high risk of serious and life threatening COVID disease," he said.
Two health workers in Alaska experienced adverse reactions to the Pfizer vaccine, health officials announced on Wednesday. One person had a more serious reaction that involved shortness of breath and skin rash, and the other had less serious reactions that included lightheadedness and a scratchy throat.
Dr. Tal Zaks, Moderna's chief medical officer, says the two vaccines are not identical despite using the same mRNA technology. Some of the lipids or fats that encase the vaccines are different.
“I would not necessarily assume” that any reactions would be the same, he said.
The FDA has found no severe allergic reactions in Moderna’s data but flagged a slightly higher rate of less serious side effects—rash, hives, itching—among participants who got the vaccine, compared with those receiving a dummy shot.
The Moderna vaccine needs to be stored at regular freezer temperatures, unlike the Pfizer vaccine that needs to be stored at -94 degrees Fahrenheit and requires specialized freezers or vast quantities of dry ice. This makes the Moderna vaccine easier to transport to rural and remote areas.
Documents prepared by FDA scientists and released ahead of the meeting of panel advisers said that a two-dose regimen of the Moderna vaccine was highly effective in preventing COVID-19 and did not raise any specific safety issues. There were no cases of severe COVID-19 among those who got the vaccine in the trial versus 30 such cases in the placebo group.
About 20 million doses are expected to be delivered this month, with the rest of the initial purchase coming in the first quarter of next year. Last week, Moderna agreed to deliver an additional 100 million doses in the second quarter.
Other companies seeking to develop a COVID-19 vaccine include AstraZeneca and Johnson & Johnson.
Hundreds of millions of additional shots will be needed to eventually vaccinate the general public, which isn’t expected until the spring or summer. The government’s Operation Warp Speed program has orders for 200 million doses of Moderna’s vaccine. That’s on top of 100 million doses of the Pfizer-BioNTech vaccine. Officials are negotiating to purchase more doses of that vaccine.
Like the first vaccine, Moderna’s vaccine will remain experimental as the company continues a two-year study needed to answer key questions, including how long protection lasts.