FDA panel backs Moderna vaccine; approval expected

WASHINGTON — Moderna’s coronavirus vaccine got the green light from a Food and Drug Administration advisory committee Thursday, paving the way for authorization of a second shot aimed at slowing a pandemic that has killed about 310,000 people in the United States.

The panel voted almost unanimously — 20 in favor, with one abstention — that the benefits of the highly effective vaccine outweighed its risks for people 18 years of age and older. The FDA plans to authorize the vaccine Friday, according to knowledgeable individuals who spoke on the condition of anonymity because they were not authorized to speak publicly about the schedule.

“I just want to make the point of what a remarkable scientific achievement this is, and pay thanks to all the scientists, present and past, who contributed to this,” James Hildreth, president of Meharry Medical College and a member of the advisory panel, said at the close of the meeting. “To go from having a [genetic] sequence of a virus in January, to having two vaccines available in December, is a remarkable achievement.”

Anticipating the authorization decision, Gen. Gustave Perna, who is overseeing the federal effort to distribute vaccines, said Monday that the government was preparing to ship almost 6 million doses of the Moderna vaccine to 3,285 locations in the first week after approval.

“It will be a very similar cadence that was executed this week with Pfizer, where we’re hitting initial sites on Monday, [followed] on Tuesday and Wednesday,” Perna said.

The advisory committee’s action came on the same day the nation set three grim single-day records, for cases (more than

250,000), hospitalized COVID-19 patients (more than 114,000) and deaths (more than 3,400). California in the past 48 hours posted more than 100,000 new infections, and the governor has readied a mass fatality plan.

At the same time, questions flared about the availability of the first coronavirus vaccine to receive federal authorization, with officials in multiple states saying they had been told their second shipments of Pfizer-BioNTech’s inoculation had been slashed for next week.

That development sowed confusion, led to dueling statements from Pfizer and federal officials about who was to blame, and raised questions about whether a promise to deliver shots to 20 million people by the end of the year would be kept.

Looming supply issues made clear that even with unprecedented scientific success, the limited availability of vaccines would not prevent a dark winter.

The FDA authorized the Pfizer-BioNTech vaccine Dec. 11. The first doses were administered Monday to health care workers. Questions about the supply have persisted, as Pfizer and the U.S. government have been in negotiations about securing more doses after the first 100 million already purchased for nearly $2 billion.

Moderna developed its vaccine in partnership with the National Institute of Allergy and Infectious Diseases, with the government underwriting the research and development of the vaccine and the advanced purchase of 200 million doses, bringing the government investment to $4.1 billion.

Early in Thursday’s meeting of the advisory committee, the FDA addressed an issue that did not directly involve the Moderna vaccine: reports of allergic reactions to the Pfizer-BioNTech vaccine, including in two health care workers in Alaska, one of whom was hospitalized. Both are recovering.

“While the totality of data at this time continue to support vaccinations under the Pfizer [emergency use authorization] without new restrictions, these cases underscore the need to remain vigilant during the early phase of the vaccination campaign,” FDA vaccine expert Doran Fink said.

The agency is working with the companies to revise fact sheets provided to patients and health care professionals, Fink said, and he underscored an existing requirement that facilities administering the vaccine ensure that treatment for a severe allergic reaction is immediately available.

The heightened concern about possible rare allergic reactions will also pertain to the Moderna vaccine, because it uses the same genetic technology as Pfizer-BioNTech. An expert panel convened by the National Institutes of Health on Wednesday tried to discern which of the components of the vaccines might trigger an allergic reaction, Moderna chief medical officer Tal Zaks said, but he added that differences between the two vaccines make it uncertain whether they both could trigger the rare reactions.

During the meeting, he and other Moderna executives explained that they saw no cases of anaphylaxis in their 30,000-person coronavirus vaccine trials. In eight previous trials of a vaccine that uses the same technology against different diseases, there had been a single report of anaphylaxis among a total of about 1,700 participants. That case occurred more than two months after the shot — suggesting there was no link.

The FDA will also closely monitor for cases of Bell’s palsy, a temporary facial paralysis, as the vaccine is rolled out to more people. There were four cases of Bell’s palsy among people that received the Pfizer-BioNTech vaccine in its trial and three in the group that received the Moderna vaccine in its trial. The FDA said there wasn’t a clear causal link but acknowledged that the combined data from the two trials raised questions.

“It’s something we are looking into and thinking much about,” said Rachel Zhang, FDA medical officer.

The Pfizer-BioNTech and Moderna vaccines both use a new genetic vaccine technology, and in addition to the impact the vaccines could have on the pandemic, there is hope the new technology could be used to rapidly create vaccines for other diseases. But the novelty of the technology, which has been tested for years in people but never deployed in an approved medical product, has been used to foster doubt about the vaccines in some social media posts. Moderna executives used Thursday’s advisory committee hearing to address those questions head on.

Melissa Moore, Moderna’s chief scientific officer, explained that a snippet of genetic material, called messenger RNA, is encapsulated in a tiny fat bubble and delivered to the body’s lymph node cells. There, cells’ protein-making machinery follow the genetic instructions to build the coronavirus spike protein. Immune cells interact with the spike to muster a protective response.

Some social media posts have stoked fear that messenger RNA will change people’s DNA. Moore explained that the messenger RNA cannot be integrated into the genome.

Questions have also circulated about the vaccine’s ingredients, especially following the reports of rare allergic reactions. Moore explained that the vaccine contains the synthetic messenger RNA and a fat bubble. It does not contain many ingredients commonly found in other vaccines, such as preservatives or adjuvants, which are used to make vaccines work better — and is not manufactured in human or animal cells.

Moderna’s vaccine was shown to be 94 percent effective in its large clinical trial; Pfizer-BioNTech’s vaccine was 95 percent effective. The efficacy was similar across age, gender and racial groups.