A pharmacist dilutes the Pfizer COVID-19 vaccine as he prepares it for administration to staff and residents at Goodwin House Bailey’s Crossroads, a senior community in Falls Church, Virginia, on December 30, 2020.
Brendan Smialowski | AFP | Getty Images
The Covid-19 vaccine appears to cause severe allergic reactions at a significantly higher rate than other vaccines in the first wave of Americans receiving life-saving vaccinations, although the reactions are still rare, the Centers for Control and United States shared Disease prevention on Wednesday with.
According to the CDC, there have been 21 cases of anaphylaxis – a severe and life-threatening allergic reaction that rarely occurs after vaccination – of nearly 1.9 million people who received their first shot of Pfizer’s Covid-19 vaccine in mid to late December, according to a study, published Wednesday in the CDC’s weekly report on morbidity and mortality.
That would mean that, according to CDC data, about 11 out of every million people vaccinated would likely experience anaphylaxis – about 10 times the rate for the flu vaccine.
Dr. Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases, told reporters on a conference call that the vaccinations are safe for the public and that the severe allergic reactions, though higher, are still considered rare.
“The anaphylaxis rate for Covid-19 vaccines may seem high compared to flu vaccines, but I want to assure you that this is still a rare finding,” Messonnier said on the call before the study was published. She added that the data applies to both Pfizer and Moderna vaccines, which use similar mRNA technology.
A Pfizer spokesman told CNBC that the company is providing prescribing information that includes a “clear” warning that medical treatment and monitoring should be readily available to someone “in the event of a rare anaphylactic event following the administration of the vaccine”.
“We closely monitor all reports indicating serious post-vaccination allergic reactions and update the labeling language as necessary,” said the spokesman.
A representative from Moderna was not immediately available to respond to CNBC’s request for comment.
Of the 21 people who experienced severe allergic reactions, 17 had a documented history of allergies or allergic reactions. Seven of these people had a history of anaphylaxis, the study said.
Most people had symptoms within 15 minutes of the shot, although anaphylaxis can occur hours after vaccination, according to the CDC. Among the 20 people with available follow-up information, all had recovered or were discharged home, according to the study.
“Of course we would all hope that any vaccine would have no adverse events, but even with 11 cases per million doses administered, it is a very safe vaccine,” said Messonnier. She added that “tremendous efforts” are being made to determine exactly what is causing the severe allergic reactions.
According to a CNBC analysis of data compiled by Johns Hopkins University, the coronavirus kills an average of 2,670 people a day in the US, making the vaccine “good value for money,” Messonnier said.
According to the preliminary guidelines of the CDC Advisory Committee on Immunization Practices, last updated in December, everyone should be observed for 15 minutes after vaccination to ensure no symptoms occur. People with a history of anaphylaxis should be observed for 30 minutes, the committee advised.
The committee also suggested that people who develop anaphylaxis after their first dose should not receive the second dose. Both drugs require two shots weeks apart for full effectiveness. The CDC study states that supplies such as adrenaline should be available at every vaccination site to treat patients who may experience severe reactions.
“Fortunately, we know how to treat anaphylaxis and we have taken precautions to ensure that the people giving the vaccine are at immunization sites ready to treat anaphylaxis,” Messonnier said.