FDA advisory panel votes to recommend Moderna vaccine for emergency use

The second vaccine against COVID-19 could start shipping as soon as this weekend

Moderna is based in Cambridge.Jessica Rinaldi/Globe Staff/file

A panel of medical experts overwhelmingly recommended Thursday that US regulators green-light a COVID-19 vaccine developed by Cambridge-based Moderna, paving the way for a much-needed second vaccine in the drive to immunize tens of millions of Americans against the deadly coronavirus.

The company’s messenger RNA vaccine, boasting a 94.1 percent effectiveness rate in clinical studies, is now likely to be approved by the Food and Drug Administration on Friday for emergency use. It would claim a place in history, alongside basketball, anesthesia, and computer spreadsheets, as another game-changing Massachusetts innovation.

FDA advisory committee members voted 20-0, with one abstention, to endorse emergency use authorization of Moderna’s vaccine, concluding its benefits outweigh its risks for people 18 years old and over. The vote followed an all-day review of clinical data and public concern over everything from side effects to distributing the vaccine fairly, with far-flung participants logging into an online video broadcast.

The outside advisers aimed to not only give the vaccine their blessing before the FDA’s decision, but also to “inspire confidence in the public,” said Dr. Eric Rubin, a committee member who is editor-in-chief of the New England Journal of Medicine and adjunct professor of immunology at Harvard’s T.H. Chan School of Public Health in Boston.

“I think this is a really opportune time to move science forward,” said another committee member, Dr. Hayley Gans, an infectious disease specialist at Stanford University’s Lucile Packard Children’s Hospital.

The lone abstention was cast by Michael Kurilla, director of clinical innovation at the NIH’s National Center for Advancing Translational Sciences. He said he thought emergency authorization for all adults was too broad and “would prefer to see it targeted to people at high risk” from COVID-19.

With the virus surging across the nation, infecting 16 million people and causing more than 300,000 deaths, shipments of nearly 6 million doses of the new vaccine could begin as soon as this weekend. The vaccine is being made at a Moderna plant in Norwood and a Portsmouth, N.H., complex run by contract manufacturer Lonza, but final distribution is being handled by a US government contractor, McKesson.

Moderna’s vaccine is a two-dose regimen, administered 28 days apart. Pending authorization, it would become the second vaccine dispatched to hospitals, nursing homes, and other sites nationwide to inoculate front-line health workers and the vulnerable elderly in the first phase of an ambitious vaccination campaign.

The first vaccine, based on similar technology, was developed by drug giant Pfizer and its German partner BioNTech, and was granted FDA emergency use authorization last week. Both prompt the body’s cells to make copies of a coronavirus spike protein, enabling the immune system to recognize COVID-19 as an invader and attack it.

In a statement Thursday night, Moderna chief executive Stéphane Bancel said the company has been working with federal officials and is ready to begin distributing its vaccine at once if the FDA gives the nod. “We look forward to getting our vaccine to people in the United States to help address this ongoing public health emergency,” Bancel said.

Because the Moderna vaccine can be stored at standard refrigerator temperatures rather than the minus-94 degrees Fahrenheit required by Pfizer’s vaccine, the new vaccine can be sent to remote locations and urban sites, like community health centers, lacking ultracold storage capacity.

Moderna’s vaccine showed high efficacy in all subgroups in a late-stage clinical trial involving 30,000 people between 18 and 95 years old, Jacqueline Miller, the company’s senior vice president and therapeutic area head, told the FDA advisory panel.

Miller said a quarter of those in the study were over 65. Ten percent were Black, 5 percent were Asian American, and 21 percent identified as Hispanic. Twenty-three percent of participants had chronic conditions, such as diabetes and heart disease, that put them at elevated risk for COVID-19.

At a public comment session, some speakers noted the clinical trials didn’t include children, pregnant women, and people living in long-term-care facilities. Those speakers said more data will be needed before the vaccine is approved for some of those groups. Others warned against letting celebrities or wealthy people “jump the line” in getting the vaccine and said large numbers of people remain hesitant to take it, including many in underserved communities.

“It’s important to emphasize that mistrust of the government and the pharmaceutical industry runs deep” among Black patients and other patients of color at Brigham and Women’s and Massachusetts General hospitals, Dr. Bisola Ojikutu, an infectious disease specialist from Boston who treats those patients, told the panel.

Ojikutu called on medical professionals to launch an educational effort targeting Black, Latinx, and indigenous communities. “What has been done is not nearly enough,” she said. “We need to reframe vaccination as a process of empowering our communities.”

Speakers said broad use of the vaccine will also hinge on practical considerations, such as making sure facilities such as Navy ships and prisons have required cold storage capacity. Dr. James Woody, a pediatric immunologist in California and retired Navy captain, said about 65 percent of Navy vessels have had coronavirus infections.

The committee also heard calls for participants in the Moderna trial to continue to be monitored, including those who had been given a placebo rather than the vaccine. The company has proposed giving placebo patients the vaccine, but it’s not clear if FDA regulators — who worry that might limit data on the vaccine’s long-term effects — will accept the plan.

“It’s important we carefully consider the volunteer’s viewpoints,” said Dr. Lindsey Baden, a Brigham and Women’s researcher who was co-principal investigator in Moderna’s vaccine study, referring to the trial participants. “Without them, clinical research cannot function.”

Many questions remain about the Moderna vaccine, including how long immunity will last and whether recipients can still transmit COVID-19 to others even if they’re protected against symptomatic disease. Because of the accelerated pace of the emergency use authorization, some questions won’t be resolved until more data can be collected.

While most side effects seen in Moderna’s clinical studies — soreness, fever, headache, and fatigue — were considered mild or moderate but not dangerous, advisory committee members peppered company officials with questions about the relatively small number of more serious adverse events. Three people who took the vaccine developed Bell’s palsy, a temporary facial paralysis. The same condition was also seen in four people in the Pfizer vaccine trial.

“There’s been no clear basis on which to conclude a causal relationship” between the vaccine and Bell’s palsy, said Dr. Rachel Zhang, an FDA medical officer. “But it’s something we’re looking into and thinking much about.”

Shortly after the FDA advisory meeting got underway Thursday, a top FDA vaccines official addressed another health concern. He told the panel that regulators were closely monitoring adverse events from the Pfizer vaccine reported at an Alaska hospital this week.

The events won’t stop the vaccine rollout because “the totality of data at this time continues to support vaccinations,” Doran Fink, deputy director of the agency’s vaccines applications office, told members of the Vaccines and Related Biological Products Advisory Committee. But he said the reported side effects “underscore the need to remain vigilant during the early phase of the vaccination campaign.”

Two health workers at Bartlett Regional Hospital in Juneau experienced worrisome reactions minutes after being vaccinated and one, who had no previous allergies, was hospitalized after she had an anaphylactic reaction with shortness of breath and an elevated heart rate.

“We anticipate that there will be additional reports, which we will rapidly investigate,” Fink said. “We learned of these cases through established safety surveillance systems that worked exactly as designed.”

He said the FDA was working with the Centers for Disease Control and Prevention to monitor cases of adverse events, and quickly communicate their findings to vaccine makers and recipients.