Moderna vaccine use on pause

No severe adverse reactions reported locally

Humboldt County is pausing administration of one of its batches of COVID-19 vaccines from Moderna after some patients experienced an allergic reaction, although no severe reactions were reported locally.

Dr. Erica S. Pan on Sunday recommended providers stop using lot 41L20A of the Moderna vaccine pending completion of an investigation by state officials, Moderna, the U.S. Centers for Disease Control and the federal Food and Drug Administration.

“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,” 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.

Humboldt County Public Health has 3,500 doses of the lot, Moderna 041L20A, of which 1,600 were designated for first doses and 1,900 for second doses, according to a Monday press release from the county.

Humboldt County Health Officer Dr. Ian Hoffman said Public Health administered hundreds of doses from the lot without any reports of severe or unusual reactions before the announcement, though the county ceased administering them after the state issued its recommendation, according to the release.

“Obviously, the goal for all of us is keeping people safe,” Hoffman said in a statement. “We’re going to pause as recommended until we hear more from the state, but without replacement doses, we’re balancing one set of risks against another.”

There are no replacement options for those doses at the moment, Hoffman said, so people with appointments or invitations to be vaccinated this week may have those appointments cancelled or rescheduled.

The state may determine the doses are safe to administer, at which point the county would begin administering the vaccines from that lot again, according to the release.

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.

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 vaccina- tion 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 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.

The Humboldt County Joint Information Center is expected to provide additional information about the Moderna 041L20A batch Tuesday.