Two health care workers at the same hospital in Alaska developed concerning reactions just minutes after receiving Pfizer’s coronavirus vaccine this week, including one staff member who was to remain hospitalized until Thursday.
Health officials said that the cases would not disrupt their vaccine rollout plans and that they were sharing the information for the sake of transparency.
The first worker, a middle-aged woman who had no history of allergies, had an anaphylactic reaction that began 10 minutes after receiving the vaccine at Bartlett Regional Hospital in Juneau on Tuesday, a hospital official said. She experienced a rash over her face and torso, shortness of breath and an elevated heart rate.
Dr. Lindy Jones, the hospital’s emergency department medical director, said the worker was first given a shot of epinephrine, a standard treatment for severe allergic reactions. Her symptoms subsided but then re-emerged, and she was treated with steroids and an epinephrine drip.
When doctors tried to stop the drip, her symptoms re-emerged yet again, so the woman was moved to the intensive care unit, observed throughout the night, then weaned off the drip early Wednesday morning, Dr. Jones said.
Dr. Jones had said earlier Wednesday that the woman was set to be discharged in the evening, but the hospital said late Wednesday that she was remaining another night.
The second worker received his shot on Wednesday and developed eye puffiness, lightheadedness and a scratchy throat 10 minutes after the injection, the hospital said in a statement. He was taken to the emergency room and treated with epinephrine, Pepcid and Benadryl, although the hospital said the reaction was not considered anaphylaxis. The worker was back to normal within an hour and released.
The hospital, which had administered 144 total doses as of Wednesday night, said both workers did not want their experiences to have a negative impact on others lining up for the vaccine.
“We have no plans to change our vaccine schedule, dosing or regimen,” Dr. Anne Zink, Alaska’s chief medical officer, said in a statement.
Although the Pfizer vaccine was shown to be safe and about 95 percent effective in a clinical trial involving 44,000 participants, the Alaska cases will likely intensify concerns about possible side effects. Experts said the developments may prompt calls for tighter guidelines to ensure that recipients were carefully monitored for adverse reactions.
Dr. Paul A. Offit, a vaccine expert and member of an outside advisory panel that recommended the Food and Drug Administration authorize the Pfizer vaccine for emergency use, said the appropriate precautions were already in place. For instance, he said, the requirement that recipients remain in place for 15 minutes after getting the vaccine helped ensure the woman was quickly treated.
“I don’t think this means we should pause” vaccine distribution, he said. “Not at all.” But he said researchers need to figure out “what component of the vaccine is causing this reaction.”
Dr. Jay Butler, a top infectious-disease expert with the Centers for Disease Control and Prevention, said the Alaska situation showed that the monitoring system worked. The agency has recommended that the vaccine be administered in settings that have supplies, including oxygen and epinephrine, to manage anaphylactic reactions.
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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:
- 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.
Millions of Americans are in line to be inoculated with the Pfizer vaccine by the end of the year. As of Wednesday night, it was unclear how many Americans so far have received it. Alex M. Azar II, the health and human services secretary, said his department would be releasing that data “several days or maybe a week into this.”
The Alaska woman’s reaction was believed to be similar to the anaphylactic reactions two health workers in Britain experienced after receiving the Pfizer-BioNTech vaccine last week. Like her, both recovered.
Those cases are expected to come up on Thursday, when F.D.A. scientists are scheduled to meet with the agency’s outside panel of experts to decide whether to recommend that regulators approve Moderna’s Covid-19 vaccine for emergency use.
Although the Moderna and Pfizer-BioNTech vaccines are based on the same type of technology and similar in their ingredients, it is not clear whether an allergic reaction to one would occur with the other. Both consist of genetic material called mRNA encased in a bubble of oily molecules called lipids, although they use different combinations of lipids.
Dr. Offit said that in both vaccines, the bubbles are coated with a stabilizing molecule called polyethylene glycol that he considered a “leading contender” for triggering an allergic reaction. He stressed that more investigation was needed.
Pfizer’s trial did not find any serious adverse events caused by the vaccine, although many participants did experience aches, fevers and other side effects. The Alaska reactions were assumed to be related to the vaccine because they occurred so quickly after the shot.
A Pfizer spokeswoman, Jerica Pitts, said the company did not yet have all of the details of the Alaska situation but was working with local health authorities. The vaccine comes with information warning that medical treatment should be available in case of a rare anaphylactic event, she said. “We will closely monitor all reports suggestive of serious allergic reactions following vaccination and update labeling language if needed,” Ms. Pitts said.
After the workers in Britain fell ill, authorities there warned against giving the vaccines to anyone with a history of severe allergic reactions. They later clarified their concerns, changing the wording from “severe allergic reactions” to specify that the vaccine should not be given to anyone who has ever had an anaphylactic reaction to a food, medicine or vaccine. That type of reaction to a vaccine is “very rare,” they said.
Pfizer officials have said the two British people who had the reaction had a history of severe allergies. One, a 49-year-old woman, had a history of egg allergies. The other, a 40-year-old woman, had a history of allergies to several medications. Both carried EpiPen-like devices to inject themselves with epinephrine in case of such a reaction.
Pfizer has said that its vaccine does not contain egg ingredients.
The British update also said that a third patient had a “possible allergic reaction,” but did not describe it.
In the United States, federal regulators issued a broad authorization for the vaccine on Friday to adults 16 years and older. Health care providers were warned not to give the vaccine to anyone with a “known history of a severe allergic reaction” to any component of the vaccine, which they said was a standard warning for vaccines.
But because of the British cases, F.D.A. officials have said they would require Pfizer to increase its monitoring for anaphylaxis and submit data on it once the vaccine comes into further use. Pfizer also said the vaccine was recommended to be administered in settings that have access to equipment to manage anaphylaxis. Last weekend, the C.D.C. said people with serious allergies could be safely vaccinated, with close monitoring for 30 minutes after receiving the shot.
Anaphylaxis can be life-threatening, with impaired breathing and drops in blood pressure that usually occur within minutes or even seconds after exposure to a food or medicine, or even a substance like latex to which the person is allergic.
Carl Zimmer contributed reporting.