Bay Area increase in mpox

Dear Public Health and Healthcare Professionals,

With the recent increase in mpox cases in our region, San Mateo County Health is recommending the JYNNEOS vaccine for groups at risk, including gay, bisexual, or other men who have sex with men (MSM) who have had a new diagnosis of one or more sexually transmitted infections or more than one sex partner in the past six months (please refer to CDC guidelines for more details on who should get vaccinated). Booster doses for persons who have received the 2-dose JYNNEOS vaccine series are currently not recommended.

Few of the Bay Area cases are epidemiologically linked. Reported regional exposure locations include Pride events, bathhouses/saunas, bars/clubs and parties.

In 2023, San Mateo County had 12 mpox clade II cases. In 2024, San Mateo County had nine mpox clade II cases and one mpox clade I case. So far in 2025 there has been one mpox clade II case.

Thank you,
The San Mateo County STI/HIV Program