California calls for halt distribution of specific batch of Modern vaccine after notification of allergic reactions

California health officials recommend a temporary halt to the distribution of a specific batch of COVID-19 vaccine from Moderna out of concern about allergic reactions.

More than 330,000 doses of the particular batch were distributed to 287 health care providers in California earlier this month.

One community vaccination clinic in particular reported up to 10 allergic reactions to the vaccine over a 24-hour period, considered an unusually high number. State officials say the expected reaction rate for similar vaccines is typically 1 in 100,000.

The name and location of the clinic were not disclosed, but the facility changed to a different batch of Modern vaccines after closing for several hours. No other group of allergic reactions have been reported.

State officials are investigating what happened at the clinic, and in the meantime, state epidemiologist Dr. Erica S. Pan recommends that doses of Moderna lot 41L20A not be distributed for now.

“Out of the extreme abundance of precaution and we also recognize the extremely limited supply of vaccines, we recommend that vendors use other available vaccine inventories and pause the administration of modern 041L20A batch vaccines until CDC, FDA investigation “Modern and the state is complete,” Pan said Sunday. “We’ll provide an update as we learn more.”