Severe allergic reactions to the Moderna COVID-19 vaccine are rare — with about 1 in 400,000 recipients suffering anaphylaxis after receiving the jab, according to the Centers for Disease Control and Prevention.
Ten people — all women — experienced the potentially deadly allergic reaction after receiving their first dose of the shot, with nine cases reported within 15 minutes of vaccination.
That statistic was out of more than 4 million doses administered between Dec. 21 and Jan. 10 and equates to 2.5 cases per million doses given, or 1 case per 400,000 doses, the agency said.
Nine of those who fell ill had a history of allergies or allergic reactions, including five who had a previous history of anaphylaxis.
Among the eight people with follow-up information available, all had recovered or been discharged.
No anaphylaxis-related deaths were reported.
More women than men have received the first dose of Moderna — which could explain the unusual finding that all 10 patients who had an anaphylactic reaction were women, the CDC explained.
The reaction requires immediate treatment, typically a shot of epinephrine. If left untreated, it can be deadly.
A total of 1,266 patients receiving their first Moderna dose experienced “adverse events,” such as a rash or respiratory problems, the agency said.
In December, a healthcare worker in Alaska was hospitalized after receiving the Pfizer/BioNTech coronavirus vaccine and experiencing an anaphylactic reaction — which has also been reported in the UK.
“A strong female predominance of anaphylaxis case reports exists for both vaccines,” the CDC noted in its Friday report.
“Finally, many persons experiencing anaphylaxis after receiving either vaccine had a history of allergies or allergic reactions, with several having experienced an anaphylaxis episode in the past.”