A Boston physician experienced a "severe" reaction just minutes after being inoculated with Moderna's vaccine on Christmas Eve.
The New York Times reported that the reaction was the first of its kind to be linked to the Moderna vaccine, which was rolled out across the United States last week.
What are the details?
Dr. Hossein Sadrzadeh, a geriatric oncologist at Boston Medical Center, had a severe anaphylactic reaction immediately after receiving the Moderna shot. Dr. Sadrzadeh told the Times the allergic reaction was the same as those he experiences with shellfish.
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He said that within minutes of the vaccine injection at 3:30 p.m., his heart rate had spiked to 150 beats per minute, about twice its normal cadence; his tongue prickled and went numb. Before long, he was drenched in a cold sweat and found himself feeling dizzy and faint. His blood pressure also plummeted, he said. His immune system, he realized, was in revolt.
"It was the same anaphylactic reaction that I experience with shellfish," Dr. Sadrzadeh said. Dr. Sadrzadeh used his EpiPen and was taken on a stretcher to the emergency room, where he was given several medications, including steroids and Benadryl, to calm the immune reactions that had overtaken his body. A record of his visit stated that he had been "seen in the ER for shortness of breath, dizziness, palpitations and numbness after receiving the Covid-19 vaccine."
"He was taken to the Emergency Department, evaluated, treated, observed and discharged. He is doing well today," David Kibbe, a spokesman for Boston Medical Center, said in a statement.
What is causing the reactions?
There have been numerous allergic reactions to coronavirus vaccines. The Food and Drug Administration said the week before Christmas that officials were investigating reactions that happened in several states with the Pfizer vaccine, which was rolled out one week prior to the Moderna vaccine.
Although experts still aren't certain what triggered the reactions, officials say the vaccines are safe.
Still, the Centers for Disease Control and Prevention issued updated guidance on the vaccine for Americans with a history of severe allergic reactions.
"If you have ever had a severe allergic reaction to any ingredient in a COVID-19 vaccine, CDC recommends that you should not get that specific vaccine. If you have had a severe allergic reaction to other vaccines or injectable therapies, you should ask your doctor if you should get a COVID-19 vaccine. Your doctor will help you decide if it is safe for you to get vaccinated," the new guidance read.
Meanwhile, Dr. Peter Marks, director of the FDA's Center for Biologics Evaluation and Research, has identified polyethylene glycol as the potential "culprit" behind the reactions.
The ingredient is present in both Pfizer's vaccine and Moderna's vaccine.
As of Sunday, more than 9.5 million doses of COVID-19 vaccine had been distributed across the U.S., and nearly 2 million Americans had been inoculated, according to CDC data.