A California state health official is calling for a pause in the distribution of a specific batch of the Moderna vaccine after an unusual number of allergic reactions from those receiving shots.

California State Epidemiologist Dr. Erica S. Pan, formerly the public health officer for Alameda County, issued a statement late Sunday indicating that providers should temporarily halt distribution of Moderna vaccine doses in a batch marked 'Lot 041L20A'. As KTVU reports, the pause is being recommended "out of an extreme abundance of caution."

"A higher-than-usual number of possible allergic reactions were reported with a specific lot of Moderna vaccine administered at one community vaccination clinic. Fewer than 10 individuals required medical attention over the span of 24 hours," Dr. Pan said in the statement.

As the Chronicle reports, the allergic reactions were found at the mass-vaccination site at San Diego's Petco Park. A total of six healthcare workers receiving vaccinations had the reactions, as the LA Times is reporting.

Reportedly, over 330,000 doses from this lot have been distributed to 287 providers across California, and they arrived between January 5 and January 12.

Pan said, "The manufacturer, Centers for Disease Control and Prevention (CDC) and the U.S. Food and Drug Administration (FDA) are reviewing the lot and related medical information."

The pause comes amid widespread fear and suspicion about the new vaccines and their possible side effects. As the LA Times reports, some of this fear is clustered in rural parts of California, where first responders are in some cases reluctant to receive vaccine doses being offered.

Add to that the story of 23 frail and elderly patients in Norway who died after receiving the Pfizer vaccine, pointing to the possibility that adverse reactions to the vaccine can be more serious for those in frail condition.

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