(Reuters) – The U.S. Centers for Disease Control and Prevention (CDC) said Wednesday it is carefully monitoring allergic reactions to Pfizer Inc and Moderna Inc’s coronavirus vaccines and urged individuals who had a severe reaction to take the second dose not to get.
In a conference call with reporters, the US Public Health Agency said allergic reactions occur at a rate of 11.1 per 1 million vaccinations. That compared to flu vaccines, where such reactions occur at a rate of 1.3 per 1 million shots.
The severe reactions are still “extremely rare,” they said, highlighting the need for people to be vaccinated when the shots become available to them, given the threat of death and serious illness from the coronavirus that has already claimed more than 357,000 lives in de United States only.
The CDC said it is closely monitoring allergic reaction incidents and plans to post weekly updates on its website.
The agency also urges that sites that deliver the vaccine are not only prepared to recognize serious allergic reactions known as anaphylaxis, but also be trained to treat them and recognize when individuals should be referred to hospitals for additional care .
CDC officials said 28 people who received the coronavirus vaccine developed by Pfizer and BioNTech had severe allergic reactions. They also noted one case of anaphylaxis, which can cause throat swelling and difficulty breathing, after a person received Moderna’s vaccine.
Officials largely attributed the difference to the fact that the Pfizer / BioNTech vaccine was approved earlier than the Moderna injection, saying the precautions apply to both.
A study published Wednesday in the CDC’s Weekly Death and Illness Report, looking at cases between December 14 and December 23, identified 21 cases of anaphylaxis following administration of 1,893,360 doses of the Pfizer / BioNTech vaccine. Of these, 71% occurred within the first 15 minutes of vaccine administration.
The UK medical regulator has said that anyone with a history of anaphylaxis or severe allergic reactions to any medicine or food should not receive the Pfizer / BioNTech vaccine.
Reporting by Michael Erman in New York, Julie Steenhuysen in Chicago, Manas Mishra and Dania Nadeem in Bengaluru; Editing by Bill Berkrot