As the coronavirus continued to surge across the United States, an independent panel of experts advising the Centers for Disease Control and Prevention voted on Saturday to endorse a second coronavirus vaccine for use in the United States.
The committee’s recommendation follows an emergency authorization granted by the Food and Drug Administration on Friday. The committee’s endorsement now awaits final approval by Dr. Robert R. Redfield, director of the C.D.C., expected shortly.
Some 5.9 million doses of the Moderna vaccine are slated for distribution starting on Sunday, and the first inoculations are expected to begin sometime on Monday.
Unlike the Pfizer-BioNTech vaccine, which was authorized for use in people 16 and older, Moderna’s vaccine is approved only for people 18 and older. While Pfizer began clinical trials of its vaccine in children as young as 12 in October, Moderna did not begin its pediatric studies until this month and does not expect to have complete data on safety and efficacy until sometime next year.
Much of the committee’s deliberations centered on the severe allergic reactions reported in several cases following injections of the Pfizer-BioNTech vaccine, which contains ingredients similar to those in Moderna’s recipe.
Six cases of anaphylaxis have now been documented in the United States, and two in Britain. Several milder allergic reactions have occurred, as well. More than 272,000 doses of the Pfizer-BioNTech vaccine have already been doled out nationwide as of Saturday, according to the C.D.C.
Allergic reactions to vaccines typically occur at a rate of about one in a million. Dr. Grace Lee, a pediatrician and vaccine expert at Stanford University, noted at the committee meeting that the estimates so far seemed to indicate that the risk of these events associated with the Pfizer-BioNTech vaccine “does seem qualitatively higher than for most typical vaccines.”
Still, she added, “for me, personally, it doesn’t necessarily change the risk-benefit balance of the Covid-19 vaccine at this time.”
Dr. Thomas Clark, an epidemiologist at the C.D.C., noted that people who experience anaphylaxis after getting a shot shouldn’t receive a second dose. It’s still unclear whether an ingredient in Pfizer’s vaccine was the direct cause of the reactions.
Some experts have pointed to polyethylene glycol, or PEG, a chemical found in many pharmaceutical products, including laxatives like Miralax, that has very rarely been found to cause allergic reactions. Both the Pfizer-BioNTech and Moderna vaccines contain PEG, though in slightly different formulations.
Dr. Sarah Mbaeyi, a medical officer at the C.D.C., said the agency was recommending that people who know they have severe allergies to any ingredient in the vaccines abstain from getting the shots for now.
People with a history of anaphylaxis to other vaccines or injectable therapies should consult their doctors and linger on site for monitoring for 30 minutes after their inoculation in case they start feeling sick. (Everyone else — including people who react strongly to other substances like food, pollen or pet dander, and people with mild allergies of any sort — may leave after 15 minutes.)
Three severe allergic reactions were reported in Moderna’s clinical trials, which included more than 30,000 adults, half of whom received a placebo instead of the vaccine. None were believed to be linked to the vaccine.
Covid-19 Vaccines ›
Answers to Your Vaccine Questions
With distribution of a coronavirus vaccine beginning in the U.S., here are answers to some questions you may be wondering about:
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- If I live in the U.S., when can I get the vaccine? While the exact order of vaccine recipients may vary by state, most will likely put medical workers and residents of long-term care facilities first. If you want to understand how this decision is getting made, this article will help.
- When can I return to normal life after being vaccinated? Life will return to normal only when society as a whole gains enough protection against the coronavirus. Once countries authorize a vaccine, they’ll only be able to vaccinate a few percent of their citizens at most in the first couple months. The unvaccinated majority will still remain vulnerable to getting infected. A growing number of coronavirus vaccines are showing robust protection against becoming sick. But it’s also possible for people to spread the virus without even knowing they’re infected because they experience only mild symptoms or none at all. Scientists don’t yet know if the vaccines also block the transmission of the coronavirus. So for the time being, even vaccinated people will need to wear masks, avoid indoor crowds, and so on. Once enough people get vaccinated, it will become very difficult for the coronavirus to find vulnerable people to infect. Depending on how quickly we as a society achieve that goal, life might start approaching something like normal by the fall 2021.
- If I’ve been vaccinated, do I still need to wear a mask? Yes, but not forever. Here’s why. The coronavirus vaccines are injected deep into the muscles and stimulate the immune system to produce antibodies. This appears to be enough protection to keep the vaccinated person from getting ill. But what’s not clear is whether it’s possible for the virus to bloom in the nose — and be sneezed or breathed out to infect others — even as antibodies elsewhere in the body have mobilized to prevent the vaccinated person from getting sick. The vaccine clinical trials were designed to determine whether vaccinated people are protected from illness — not to find out whether they could still spread the coronavirus. Based on studies of flu vaccine and even patients infected with Covid-19, researchers have reason to be hopeful that vaccinated people won’t spread the virus, but more research is needed. In the meantime, everyone — even vaccinated people — will need to think of themselves as possible silent spreaders and keep wearing a mask. Read more here.
- Will it hurt? What are the side effects? The Pfizer and BioNTech vaccine is delivered as a shot in the arm, like other typical vaccines. The injection into your arm won’t feel different than any other vaccine, but the rate of short-lived side effects does appear higher than a flu shot. Tens of thousands of people have already received the vaccines, and none of them have reported any serious health problems. The side effects, which can resemble the symptoms of Covid-19, last about a day and appear more likely after the second dose. Early reports from vaccine trials suggest some people might need to take a day off from work because they feel lousy after receiving the second dose. In the Pfizer study, about half developed fatigue. Other side effects occurred in at least 25 to 33 percent of patients, sometimes more, including headaches, chills and muscle pain. While these experiences aren’t pleasant, they are a good sign that your own immune system is mounting a potent response to the vaccine that will provide long-lasting immunity.
- Will mRNA vaccines change my genes? No. The vaccines from Moderna and Pfizer use a genetic molecule to prime the immune system. That molecule, known as mRNA, is eventually destroyed by the body. The mRNA is packaged in an oily bubble that can fuse to a cell, allowing the molecule to slip in. The cell uses the mRNA to make proteins from the coronavirus, which can stimulate the immune system. At any moment, each of our cells may contain hundreds of thousands of mRNA molecules, which they produce in order to make proteins of their own. Once those proteins are made, our cells then shred the mRNA with special enzymes. The mRNA molecules our cells make can only survive a matter of minutes. The mRNA in vaccines is engineered to withstand the cell’s enzymes a bit longer, so that the cells can make extra virus proteins and prompt a stronger immune response. But the mRNA can only last for a few days at most before they are destroyed.
At the meeting, experts also raised concerns about four cases of a temporary facial paralysis called Bell’s palsy, three of which occurred in the vaccine group in the Moderna trial. (Four cases of Bell’s palsy also arose in Pfizer’s trials, all in the vaccine group.)
There’s no evidence yet that directly links the paralysis to either vaccine, and Dr. Jacqueline Miller, a senior vice president at Moderna, said her company was continuing to monitor vaccine recipients for the side effect.
More than half of people who received the Moderna vaccine in clinical trials reported uncomfortable symptoms, including fatigue, headaches and soreness, after their second shot, given about four weeks after the first. Some volunteers also developed a fever or a rash around the injection site.
Incidents like these appear to be much more common with Moderna’s vaccine than Pfizer’s, which containers a smaller dose of the active ingredients. But most of the side effects disappeared within a day or so of the inoculation.
Temporary symptoms after a vaccination are relatively common. Often, they are the outward signs of an immune system hard at work, preparing the body to fend off disease in the future.
Neither Moderna nor Pfizer has yet collected data in people who are pregnant or breastfeeding. But none of the 13 volunteers who became pregnant while participating in Moderna’s clinical trials, six of whom received the vaccine, reported harmful effects.
More than 500 Americans who have gotten a dose of Pfizer’s vaccine were pregnant at the time of their injection.
Many scientists believe the coronavirus poses a far greater risk to pregnant or breastfeeding people than the vaccine does. Stephanie Langel, an immunologist and virologist at Duke University, was prioritized to receive the vaccine because she is conducting research on the coronavirus. She got her shot on Friday.
“For me, it’s just a no-brainer,” she said, because of her frequent exposure to the virus. “It’s about your evaluation of risk.”
During the meeting, scientists and clinicians underscored the importance of bringing vaccinations to communities that have been disproportionately affected by the pandemic, including people in correctional facilities.
Experts have repeatedly noted the importance of partnering with representatives from communities of color to reaffirm vaccine safety and efficacy for people who might be hesitant or skeptical of the shots. (Exceedingly few people who identified as American Indian, Alaska Native, Native Hawaiian or Pacific Islander participated in Moderna’s trials.)
Dionne Brown, the director of nursing at Summit Rehabilitation and Care Community in Aurora, Colo., told The New York Times that she had been a “a little bit apprehensive about the side effects.” But after lengthy discussions with her colleagues about how safe and effective the vaccines have been shown to be, “I feel comfortable with taking it,” she said.
Ms. Brown, a mother of six, hopes to set an example for her family and community, as well as the other staff members and elderly residents in her long-term care facility.
“That’s what my aim and goal is,” she said. “That they will see me get it and hopefully feel comfortable.”
In a second session on Sunday, C.D.C. officials and scientists will deliver more guidance about allocating the newly cleared vaccines, and vote on the prioritization of people to receive vaccinations.