The Food and Drug Administration’s decision to clear the vaccine, developed by Massachusetts biotechnology company Moderna in partnership with the National Institute of Allergy and Infectious Diseases, arrives at the end of a historic week in medicine — as health-care workers began receiving inoculations of the first coronavirus vaccine, developed by Pfizer and BioNTech, which was cleared by the agency Dec. 12.
The first shots in a national mass vaccination campaign this week delivered great hope but also exposed the distribution and supply challenges that will now move to the forefront, as companies, the federal government and states attempt to work in concert to maintain ambitious timelines. Two health-care workers in the United Kingdom had treatable allergic reactions after being vaccinated with the Pfizer-BioNTech shot a little over a week ago. In the United States, the FDA said Friday night, the agency is investigating “about five” reports of allergic reactions. The cases highlight the challenges that could lie ahead as public health experts work to build trust in the vaccines.
“To get another very important vaccine into play is just, yet again, another step toward what the ultimate goal is: to get enough people vaccinated so you could essentially end the epidemic as we know it in this country,” Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases, said. “I believe that’s possible.”
The authorization of a second vaccine — which came as the death toll from the virus in the United States surpassed 312,000 — will have an immediate practical impact that may begin to ease some of the logistical challenges, doubling to roughly 20 million the number of people government officials say they can vaccinate with a first shot before the end of the year. It will free the country from the precarious position of being reliant on a single manufacturer as production ramps up of a type of vaccine that has never been made on a massive scale. And it adds a vaccine that can be stored in a regular freezer, making it easier to distribute to large swaths of the country, in contrast to the specialized ultracold freezers and dry ice coolers needed for the Pfizer-BioNTech vaccine.
The successes also represent a decisive moment in scientific history. Scientists took a novel technology and leveled it against a new virus, developing and deploying in under a year two vaccines that are 94 to 95 percent effective in clinical trials, rivaling some of the most effective vaccines in the world’s medicine cabinet.
“It’s astonishing. Not in our wildest dreams would we imagine the results that we received,” said Lisa A. Jackson, a senior investigator at Kaiser Permanente Washington Health Research Institute who has worked on more than 60 vaccine trials. In mid-March, she launched what could be the most consequential one — a small safety test of the Moderna vaccine in 45 healthy, young volunteers. “To have two such vaccines — it’s just amazing.”
In a media call Friday night, FDA officials called the authorization of a second vaccine a milestone and said they are looking into reports of allergic reactions related to the Pfizer-BioNTech vaccine. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, which regulates vaccines, said the FDA and the Centers for Disease Control and Prevention have met daily to evaluate the reports, including a case in Alaska in which a woman was hospitalized.
He said scientists don’t know what might be causing the reactions but speculated a possible “culprit” could be polyethylene glycol, a component in both the Pfizer-BioNTech and Moderna vaccines. The substance is commonly used in pharmaceutical preparations, and scientists are wondering if more people react to it than was thought.
The FDA, in its patient information sheets, says individuals who know they are allergic to any components in the authorized vaccines should not receive the shots. The government requires that medical supplies to treat severe allergic reactions be available wherever vaccines are being administered.
The development of the vaccines is a testament to a single-minded focus by private industry and the government, which built on decades of basic research to accomplish an urgent goal. Tens of thousands of volunteers agreed to roll up their sleeves in hopes they could play a small part in bringing the world back to normal. One of those volunteers was Jennifer Haller, 44, of Seattle, who was the first person to receive the Moderna vaccine March 16 — at a time when it remained unclear what trajectory the pandemic would take.
“This was a way that I could contribute,” Haller said. “I have a lot of stability in my life — I have a full-time job, friends and family nearby. I wanted to take a risk like this when so many others can’t. They have so many more pressing, immediate needs that they need to take care of.”
The first doses of the Moderna vaccine, which is authorized for people 18 and older, will probably ship this weekend, with nearly 6 million expected to be distributed during the first week to health-care workers and nursing home residents. An additional 2 million doses of the Pfizer-BioNTech vaccine are expected to be shipped. The clearance of both vaccines marks a transition from an uncertain scientific quest to a massive logistics enterprise — one that already experienced missteps this week as several trays of the Pfizer-BioNTech vaccine shipped to Alabama and California got too cold, and had to be returned, and states questioned why their shipments for next week had been slashed.
In that way, the Moderna vaccine offers a clear advantage. While the Pfizer-BioNTech vaccine must be kept at ultracold temperatures in specialized freezers or carefully maintained dry ice containers, the Moderna vaccine can be stored at regular freezer temperatures long-term and at refrigerator temperatures for up to a month. That will expand the settings where it can be used to rural areas, pharmacies or medical offices that lack specialized equipment.
“Moderna is much easier in terms of transportation; it has a more forgiving cold chain. It doesn’t have to be kept as cold,” Amesh Adalja, senior scholar at the Johns Hopkins Center for Health Security, said.
At an FDA advisory committee meeting Thursday on the Moderna vaccine, Gwen Schell, a nurse from Panhandle Health District’s home health care in Idaho, said the shots are desperately needed in rural areas. “We have very limited nursing staff in this part of the United States,” Schell said. “We have seen an uptick in people being sent home from the hospital who are not meant to be home.”
Having a second supplier, particularly at a time when there are not enough doses, could ease the delays and hiccups that many vaccine experts think are likely to occur over the next months. Bloomberg News reported Thursday that 400,000 doses of a recent manufacturing batch from Moderna had to be tossed after a filtration problem.
Bruce Y. Lee, a professor of health policy and management at City University of New York Graduate School of Public Health and Health Policy, said that during the 2009 H1N1 pandemic, he was part of a team trying to project where limited vaccine doses could have the greatest impact. A recurring theme was vaccine companies missing their targets, requiring last-minute recalculations.
“On a weekly basis, we would get updated vaccine production numbers — and it was consistently, week after week, delayed,” Lee said. “We would basically run scenarios to show folks at [the Department of Health and Human Services], ‘This is what it means, given the fact you have limited vaccines, about who should get the vaccines first: In these neighborhoods, it would have a greater impact on the pandemic.’"
Kendall Hoyt, a vaccine and biosecurity expert at Dartmouth College, said the addition of vaccine manufacturers such as Moderna to Pfizer-BioNTech’s pioneering effort is badly needed because there is no way to know how vaccine makers will be affected by what she predicted could be severe supply shortages.
“There is going to be a global crush of demand for all the ingredients — the vials, the syringes, the raw materials,” she said. “We have never tried to make as much vaccine at once.”
One of the challenges of scaling up vaccine production is that the technology in the Pfizer-BioNTech and Moderna vaccines has never been used in approved medical products or produced in such large amounts at pharmaceutical quality standards.
Since 1961, scientists have known about messenger RNA, genetic material that makes life possible, taking instructions inscribed in DNA and delivering them to the protein-making parts of the cell. Both the Moderna and Pfizer-BioNTech vaccines harness this natural process in a vaccine, delivering to the body’s cells synthetic RNA that carries the blueprint to build the spiky proteins on the coronavirus surface. The cells follow the instructions to make the spike proteins, and the immune system learns from those spikes to recognize the real thing.
There isn’t yet a long safety track record for the technology, but the platform has been in human tests for years, including in tens of thousands of people in the coronavirus vaccine trials in recent months. While most infectious-disease experts are focused on finding ways to deploy the technology as quickly as possible so that vaccines can begin to blunt the crisis this winter, many are also thinking of the inevitability of the next pandemic — and the proof-of-concept that these two successes represent.
“This is all we’ve been doing for nine months: It’s eat, sleep, vaccinate, and that’s been an exhilarating but exhausting time for all of us,” said C. Buddy Creech, director of the Vanderbilt Vaccine Research Program. “When we got word that the vaccines were over 90 percent effective, I think there was a collective sigh across all of vaccinology that recognized both the impact for this pandemic but also how we can respond very quickly to future pandemics.”
Krutika Kuppalli, an infectious-disease specialist at the Medical University of South Carolina, said there is intense interest among health workers to be vaccinated quickly. She said 600 to 700 health-care workers were vaccinated with the Pfizer-BioNTech shots Tuesday, the first day of inoculation. Slots for coming days are filling rapidly, she said.
With demand for coronavirus vaccines sure to outstrip supply for many months and beyond, Kuppalli welcomed the authorization of the Moderna product. “We are going to need multiple vaccines” to inoculate the nearly 8 billion people on Earth, she said.
The FDA authorization capped months of frenzied activity at the agency, whose vaccine experts have been working intensely with manufacturers to bring coronavirus vaccines to market.
Pfizer-BioNTech applied to the agency for emergency authorization Nov. 20, and Moderna filed its request just 10 days later. Federal officials have said two more manufacturers — Johnson & Johnson and AstraZeneca — could seek FDA clearance early next year. Novavax is expected to start its large trial in coming weeks, but a sixth vaccine backed by the U.S. government from Sanofi and GlaxoSmithKline has been delayed after its shot failed to trigger a strong enough response in older adults.
Operation Warp Speed, the Trump administration’s initiative to accelerate the availability of vaccines, has invested almost $4.1 billion in Moderna’s vaccine development, clinical trials and manufacturing. The government has bought 200 million doses of the vaccine and retains options for hundreds of millions more. In a break from traditional practice, manufacturing began while the vaccine still was being tested in a clinical trial — to speed distribution once cleared by the FDA.