California Clinic Suspends Use of Large Batch of Moderna Vaccines After Allergic Reactions

After multiple people at a California clinic had obvious allergic reactions, state health officials ordered state-wide providers on Sunday to suspend administration of doses from one batch of COVID-19 vaccine that arrived from Moderna.

The step, made “out of an extreme abundance of caution,” ensures that in the midst of an already sluggish vaccine rollout, 330,000 doses distributed to 287 providers throughout the state will not be used.

“A higher-than-usual number of possible allergic reactions were reported with a specific lot of Moderna vaccine administered at one community vaccination clinic,” California State Epidemiologist Dr. Erica Pan said.

Officials said that less than 10 individuals in over a 24-hour span needed medical attention but did not explain their allergic reactions.

State health officials said in a news release that they “All appeared to be experiencing a possible severe allergic reaction during the standard observation period – a type of adverse event that the CDC reports some people have experienced when receiving a COVID-19 vaccine.”

Meanwhile, before the end of the inquiry, suppliers were advised to use doses from other available vaccine inventories. The pause relates only to one lot from Moderna and not all of the company’s vaccine doses.

Between Jan. 5 and 12, the 330,000 doses of the affected lot arrived in California and were spread throughout the state.

Health officials have reminded people that there is a very small chance of a significant adverse reaction to the COVID-19 vaccine and that the anticipated rate of anaphylaxis is around 1 in 100,000.

“The state has not been notified of any other cluster or individual events related to this lot,” officials said.

According to the state, after closing for a few hours, the clinic that had the allergic reactions turned to another batch of Moderna vaccine. Officials didn’t reveal the name or location of the clinic.