The California state government’s top epidemiologist recommended halting the use of more than 300,000 doses of the Moderna coronavirus vaccine after some who received it developed allergic reactions. Dr. Erica Pan wrote, “Out of an extreme abundance of caution and also recognizing the extremely limited supply of vaccine, we are recommending that providers use other available vaccine inventory.” Lot 41L20A—330,000 doses of the vaccine that arrived California between Jan. 5 and Jan. 12—caused fewer than 10 recipients to require medical attention over a 24-hour period after they received the shot. Pan has called for a state investigation into the doses. She did not identify the patients or specify exactly how many experienced adverse reactions. Moderna told the Associated Press it “is unaware of comparable adverse events from other vaccination centers which may have administered vaccines from the same lot.”