California State Epidemiologist Erica S. Pan asked providers to halt shots from lot 41L20A of the Moderna COVID-19 vaccine as the state investigates reports of allergic reactions. 

On Sunday, Jan. 17, Pan issued a statement detailing the state’s precautions. 

“Our goal is to provide the COVID vaccine safely, swiftly and equitably,” said Pan. “A higher than usual number of possible allergic reactions were reported with a specific lot of Moderna vaccine administered at one community vaccination clinic in San Diego. Fewer than 10 individuals required medical attention over the span of 24 hours. Out of an extreme abundance of caution and recognizing the extremely limited supply of vaccines, we recommend that providers use other available vaccine inventory and pause the administration of vaccines from Moderna Lot 041L20A until the investigation by the CDC, FDA, Moderna and the state is complete. We will provide an update as we learn more.”

According to the California Department of Public Health, the patients appeared to be experiencing possible anaphylaxis during the standard observation period. The Centers for Disease Control and Prevention has reported that some people experience adverse effects when receiving a COVID-19 vaccine. While no vaccine or medical procedure is without risk, the risk of a serious adverse reaction is small. While less data exists on adverse reactions related to the Moderna vaccine, a similar vaccine shows that the expected rate of anaphylaxis is approximately 1 in 100,000.

More than 330,000 doses from this Moderna lot were distributed to 287 providers across the state. The shipments arrived in California between Jan. 5 and 12. The state has not been notified of any other cluster or individual events related to this lot. There are no immediate replacement doses during this pause. 

“San Bernardino County received doses from the lot, but no notable side effects have been reported in connection with any of the vaccines,” said county spokesman David Wert in an email on Jan. 19. 

On Jan. 13 and Jan. 14, San Bernardino County announced that people in the county’s Phase 1A Tier 3 of the COVID-19 vaccine allocation can now start making appointments as well as anyone over the age of 65. Previously, only those in Tier 1 and 2 could schedule appointments. 

Tier 3 is specialty clinic workers, laboratory workers, dental clinics and pharmacy staff.

The county also announced that mobile vaccination units are coming soon to serve residents with travel challenges, including seniors and residents in the most remote areas of the 20,000-square-mile county. The county is also working on setting up community-based vaccination sites similar to the testing sites and a super-site for vaccinations. 

As of Jan. 19, the county has received 75,900 first doses of the vaccine and have 38,770 people have been vaccinated. 

Those eligible within the county can make an appointment to get vaccinated at There are facilities in San Bernardino, Ontario, Hesperia, Rialto, Redlands, Upland, Lake Arrowhead, Fontana, Highland, Victorville, Chino Hills, Yucca Valley, Rancho Cucamonga and Apple Valley. 

Seniors can also sign up for email and text notifications to receive alerts about vaccination opportunities and other vaccination news through the 65+ Vaccine Notification Sign Up. Those who need assistance with appointments or signing up for notifications can call the COVID-19 hotline from 9 a.m. to 5 p.m. Monday through Friday at (909) 387-3911.