The California state epidemiologist asked for more than 300,000 doses of the coronavirus vaccine developed by Moderna to be suspended after some people received medical attention for possible serious allergic reactions.
Dr. Erica S. Pan advised suppliers on Sunday to stop using Moderna’s vaccine batch 41L20A until an investigation is completed by state authorities, Moderna, the Centers for Disease Control and Prevention. (CDC for the acronym in English) and the Food and Drug Administration (FDA, for the acronym in English).
“As an added precaution, and also because we recognize the extremely limited supply of vaccines, we recommend that providers make use of other available vaccines,” Pan said in a statement.
He noted that more than 330,000 doses of the batch arrived in California between January 5 and 12 and were distributed to 287 suppliers.
We recommend that you:
Fewer than 10 people, all of whom received the vaccine at the same location, needed medical attention for 24 hours, Pan said. No comparable groups were found.
Pan has not specified the number of cases involved or the location where they occurred.
However, six health workers in San Diego had allergic reactions to vaccines received at a mass inoculation center on January 14. The site was temporarily closed and is now using other vaccines, KTGV television reported.
Moderna said in a statement that the company “is not aware of similar side effects from other vaccination centers that may have administered vaccines from the same batch.”
The CDC has said that COVID-19 vaccines can cause side effects for several days, such as fever, chills, headache, bloating or fatigue, “which are normal signs that your body is developing protection.”
However, serious reactions are extremely rare. Pan said that, in a vaccine similar to Moderna’s, the rate of anaphylaxis – in which an immune system response can block breathing and cause a drop in blood pressure – was about one in 100,000.
Meanwhile, California counties continued to demand more doses of the COVID-19 vaccine as part of the state’s effort to reduce the infection rate, leading to record numbers of hospitalizations and deaths.