US health officials who are closely tracking the potential side effects of the first licensed COVID-19 vaccine say they have seen six cases of severe allergies out of more than a quarter of a million injections.
The Centers for Disease Control and Prevention said that more than 272,000 injections of the Pfizer vaccine had been given nationwide as of Saturday morning. Half a dozen cases of allergies have been reported and have included one person with a history of vaccination reactions.
Health officials are closely monitoring for such side effects.
In the United States, vaccine recipients are supposed to loosen up after the injection if signs of an allergic reaction appear. The CDC says all cases occurred within the recommended surveillance window and were treated promptly.
The numbers were discussed at a committee meeting that advises the Centers for Disease Control and Prevention on vaccines. On Saturday, the group endorsed Moderna’s COVID-19 vaccine, which has received an emergency clearance.
Less serious side effects were also rare. Of the first 215,000 people vaccinated in the United States, less than 1.5% had problems that left them unable to perform their normal activities or required medical care.
Many vaccines can cause temporary discomfort, such as an arm infection or some flu-like symptoms. COVID-19 vaccines tend to cause more reactions than the flu vaccine, and some hospitals are astonished at times when their employees get vaccinated to avoid hiring problems.