California calls for disruption of specific lot of Moderna vaccine after allergic reactions have been reported

California health officials recommend that the distribution of a certain amount of Moderna’s COVID-19 vaccine be temporarily halted due to concerns about allergic reactions.

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

One particular vaccination clinic in the community reported allergic reactions to the vaccine within a period of 24 hours, which is considered an exceptionally high number. Government officials say the expected response rate to similar vaccines is typically around 1 in 100,000.

The name and location of the clinic were not disclosed, but the facility switched to a different amount of Moderna vaccines after closing several hours. No other group of allergic reactions was reported.

Government officials are investigating what happened in the clinic, and dr. Erica S. Pan, state epidemiologist, recommends that doses of Moderna lot 41L20A not be distributed for the time being.

“Out of extreme caution and also the extremely limited amount of vaccine, we recommend that suppliers use other available vaccine supplies and interrupt the administration of vaccines from Moderna Lot 041L20A until the investigation is completed by the CDC, FDA, Moderna and the state,” Pan Sunday said. “We will provide an update as we learn more.”