WASHINGTON – Two health care workers at the same Alaska hospital developed reactions just minutes after receiving the coronavirus vaccine from Pfizer this week, including a worker who was supposed to stay in the hospital until Thursday.
Health officials said the cases would not disrupt their plans to launch vaccines and that they would share the information for the sake of transparency.
The first worker, a middle-aged woman with no history of allergies, had an anaphylactic reaction that began 10 minutes after receiving the vaccine at the Bartlett Regional Hospital in Juneau on Tuesday, a hospital official said. She had a rash over her face and trunk, shortness of breath, and an increased heart rate.
Dr. Lindy Jones, the hospital’s emergency room medical director, said the worker was first given a shot of adrenaline, a standard treatment for severe allergic reactions. Her symptoms subsided, but then came back and she was treated with steroids and an adrenaline drop.
When the doctors tried to stop the drip, her symptoms reappeared, so the woman was taken to the intensive care unit, which was observed all night, and then taken off the drip early Wednesday morning, Dr. Jones.
Dr. Jones had said earlier Wednesday that the woman should be discharged that evening, but the hospital said late Wednesday that she would be staying one more night.
The second worker received his shot Wednesday and developed eye swelling, lightheadedness and a sore throat 10 minutes after the injection, the hospital said in a statement. He was taken to the emergency room and treated with adrenaline, Pepcid, and Benadryl, though the hospital said the reaction wasn’t anaphylaxis. The worker was back to normal within an hour and was released.
The hospital, which had given a total of 144 doses on Wednesday night, said both workers didn’t want their experience to negatively impact others who line up for the vaccine.
“We have no plans to change our vaccination schedule, dosage, or treatment regimen,” said Dr. Anne Zink, Alaska’s chief medical officer, in a statement.
Although the Pfizer vaccine was shown to be safe and 95 percent effective in a clinical trial of 44,000 participants, the Alaska cases are likely to heighten concerns about possible side effects. Experts said developments could lead to calls for stricter guidelines to ensure recipients were carefully monitored for side effects.
Dr. Paul A. Offit, a vaccine expert and a member of an outside advisory panel that recommended the Food and Drug Administration approve Pfizer’s emergency vaccine, said the appropriate precautions have already been taken. For example, he said, requiring recipients to remain in place for 15 minutes after receiving the vaccine helped ensure that the woman was treated quickly.
“I don’t think this means we should take a break,” he said. “Not at all.” But he said the researchers need to find out “which component of the vaccine is causing this response”.
Dr. Jay Butler, a leading infectious disease expert with the Centers for Disease Control and Prevention, said the situation in Alaska showed that the surveillance system was working. The agency has recommended that the vaccine be given in environments where oxygen and adrenaline are available to treat anaphylactic reactions.
Millions of Americans are expected to be vaccinated with the Pfizer vaccine by the end of the year. As of Wednesday evening, it was unclear how many Americans had received it so far. Alex M. Azar II, the secretary for health and human services, said his department would release these data “several days or maybe a week later.”
The Alaska woman’s response was believed to be similar to the anaphylactic reactions two health workers in the UK had after receiving the Pfizer BioNTech vaccine last week. How they both recovered.
These cases are expected to occur Thursday, when FDA scientists are due to meet with the agency’s external panel of experts to decide whether regulators should recommend Moderna’s Covid-19 vaccine for the emergency.
Although the Moderna and Pfizer-BioNTech vaccines are based on the same technology and are similar in their ingredients, it is not clear whether an allergic reaction to one vaccine would occur with the other. Both are made up of genetic material called mRNA, which is trapped in a bubble of oily molecules called lipids, although they use different combinations of lipids.
Dr. Offit said the bladders in both vaccines are coated with a stabilizing molecule called polyethylene glycol, which he saw as a “prime candidate” for causing an allergic reaction. He stressed that further research was needed.
Pfizer’s study did not identify serious adverse events from the vaccine, although many participants experienced pain, fever, and other side effects. The Alaskan reactions were thought to be related to the vaccine because they came on so quickly after the shot.
A Pfizer spokeswoman, Jerica Pitts, said the company doesn’t have all the details of the Alaska situation but is working with local health officials. The vaccine contains information that indicates that medical treatment should be available in the event of a rare anaphylactic event, she said. “We will closely monitor any reports suggestive of serious post-vaccination allergic reactions and update the labeling language as necessary,” said Ms. Pitts.
After workers in the UK fell ill, authorities there warned against giving the vaccines to anyone with a history of severe allergic reactions. They later clarified their concerns and changed the wording of “severe allergic reactions” to mean 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 response to a vaccine is “very rare,” they said.
Pfizer officials said the two Britons who had the reaction had severe allergies in the past. A 49-year-old woman has had egg allergies in the past. The other, a 40-year-old woman, had a history of allergies to several drugs. Both wore EpiPen-like devices to inject adrenaline in the event of such a reaction.
Pfizer has said that its vaccine does not contain egg ingredients.
The UK update also said a third patient had a “possible allergic reaction” but did not describe it.
In the United States, federal regulators on Friday gave adults ages 16 and older full approval for the vaccine. Healthcare providers have been warned not to give the vaccine to anyone with a “known history of a severe allergic reaction” to any component of the vaccine. This is a standard warning for vaccines.
Due to the UK cases, FDA officials have announced that they will require Pfizer to step up surveillance for anaphylaxis and provide data on it once the vaccine continues to be used. Pfizer also said that it was recommended that the vaccine be given in environments with access to anaphylaxis treatment equipment. Last weekend, the CDC said people with severe allergies could be safely vaccinated, with close monitoring 30 minutes after receiving the shot.
Anaphylaxis can be life-threatening, with difficulty breathing and drops in blood pressure that usually occur within minutes or even seconds of contact with a food or drug or even a substance such as latex that the person is allergic to.
Carl Zimmer contributed to the reporting.
