SAN LUIS OBISPO — The San Luis Obispo County Office of Public Health announced starting today, Jan. 19, local public vaccination clinics will follow State direction and stop administering some Moderna COVID-19 vaccines due to reports of possible allergic reactions.

The County Public Health Department confirmed today that it received 4,400 doses of the single lot
in question, but none of these doses have been administered yet in SLO County. These doses will be
reserved until the State provides further guidance and validates their safety.

According to the report, the State will not immediately replace the doses at this time, which could cause a temporary setback in the distribution of second doses to people in SLO County.

“Our priority from day one has been to administer vaccines effectively and safely,” said Dr. Penny
Borenstein, County Public Health Officer. “While some mild side effects from the Moderna vaccine
are normal, we want to be especially careful to make sure all vaccines are safe for our community.
We will await further guidance from the CDC and the State before administering these doses.”


According to the State, a higher-than-usual number of adverse events were reported this week with
a specific lot of Moderna vaccine (Moderna Lot 041L20A) administered at a single California clinic.

In the Public Health Officer’s report, it states that while fewer than ten individuals in the state had an adverse reaction to the Moderna vaccine, an investigation will be conducted by the CDC, FDA, Moderna, and the State to assess whether these doses can be safely administered to the public.

The State Epidemiologist Dr. Erica Pan, recommended
“pausing” administration of the lot until the issue could be investigated further.

According to the report, local officials say this investigation will not delay first-time vaccination appointments. All first-dose appointments will remain in effect, but second-dose appointments may be restricted until the new Moderna supply is delivered.

While the County Health Officer has stressed in prior press briefings that the second dose of vaccine is highly recommended within a specific timeline to ensure maximum immunity against COVID-19, public health officials now say receiving the second dose a few weeks later than expected will not be detrimental to the health of the patient nor will it require them to start the vaccine series over.

Residents awaiting their second dose of vaccine will be informed by text or email when new appointments are available.

For more information regarding the COVID-19 vaccine in SLO County, visit