California's state epidemiologist is urging a halt to more than 300,000 coronavirus vaccinations using a Moderna version because some people have received medical treatment for possible severe allergic reactions. Dr. Erica Pan on Sunday recommended providers stop using Lot 41L20A of the Moderna vaccine pending completion of an investigation by state officials, Moderna, the Centers for Disease Control and Prevention, and the federal Food and Drug Administration. "We are recommending that providers use other available vaccine inventory," Pan said in a statement. She said more than 330,000 doses from the lot arrived in California between Jan. 5 and Jan. 12 and were distributed to 287 providers. Fewer than 10 people, who all received the vaccine at the same community site, needed medical attention over a 24-hour period, Pan said. No other similar clusters were found, the AP reports.
Pan did not specify the number of cases involved or where they occurred. However, six San Diego health care workers had allergic reactions to vaccines they received at a mass vaccination center on Jan. 14. The site was temporarily closed and is now using other vaccines, KTGV-TV reported. Moderna in a statement said the company "is unaware of comparable adverse events from other vaccination centers which may have administered vaccines from the same lot." The CDC has said COVID-19 vaccines can cause side effects for a few days that include fever, chills, headache, swelling, or tiredness, “which are normal signs that your body is building protection." However, severe reactions are extremely rare. Pan said that in a vaccine similar to Moderna, the rate of anaphylaxis—in which an immune system reaction can block breathing and cause blood pressure to drop—was about 1 in 100,000.
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