SF mpox cases rising, most cases among those vaxxed

Cases of mpox are rising again in San Francisco, according to an announcement from the city’s public health department August 14. Most are in people who have gotten vaccinated against the virus and their symptoms are mild, reported local health officials.

“Since late June 2025, 14 San Francisco residents have been diagnosed with mpox, which is an increase from an average of ~1 diagnosis per month from January-May 2025,” an email stated. “A summer and fall increase in mpox cases has occurred in San Francisco since 2022, which may be associated with larger events and summer and fall gatherings.”

As the Bay Area Reporter previously reported, mpox cases ticked up in fall 2023 and there were more cases by the end of May 2024 nationwide than by the same time in 2023. At no point, however, did the number of cases reach the severity of the 2022 outbreak.

The city saw 840 cases total that year. As of August 9, 2025, San Francisco has only seen 142 since that time.

The San Francisco Department of Public Health reports that this year, “most mpox cases in SF have occurred among individuals fully vaccinated with Jynneos.”

“These cases have typically been mild, with no signs of severe infection or need for hospitalization,” according to an update from the agency’s Population Health Division. “While no vaccine is 100% effective, Jynneos continues to offer the best protection against the virus.”

Dr. Julia Janssen with the health department told the B.A.R. in a phone interview that “a little over half” the cases this year have been in people fully vaccinated. 

“If someone is fully vaccinated and they get a rash, we want to remind people to get tested and confirm it is mpox,” Janssen said. “Oftentimes, in people who are fully vaccinated, we are seeing less serious illness than in people unvaccinated, and especially compared with we saw in 2022.”

Back in November 2023, the department reported that most cases, 57%, were in unvaccinated San Franciscans. Of those who’ve been fully vaccinated, less than 1% have reported a case of mpox, the department continued.

The two doses are administered 28 days apart. If a person received one dose over 28 days earlier, the second dose can be administered immediately. Vaccination is not recommended in patients who have previously been diagnosed with mpox, as infection likely confers immune protection.

Janssen said that people should ask their health care providers or systems for the vaccination if they are men who have sex with men or are transgender and they have not received it. 

“People can also check with CVS, Walgreens, Safeway, or Costco,” Janssen said. “We also recommend people check with insurance to see that it’s covered. Especially if they are in specific health systems like Kaiser, we recommend you seek vaccination there as it may not be covered at a retail pharmacy or check with your insurance first. If you do not have insurance, sf.gov/mpox lists other locations where the vaccine is available.”

The San Francisco AIDS Foundation encouraged people to get vaccinated.

“The slight uptick in the number of mpox cases this summer should not be cause for alarm since the number of overall cases remains quite small,” stated Jorge Roman, who has a master of science in nursing and is director of nurse practitioner and research services at SFAF. “That said, we do encourage community members to get vaccinated for mpox if they may be at risk and have not yet received the Jynneos vaccine, since vaccination significantly reduces risk of infection. We also remind folks to get screened for mpox if they experience symptoms. Community members are encouraged to call or make an appointment at SFAF’s Magnet clinic or another clinical provider with questions or concerns.”

The health department asks doctors to counsel patients on condom use, and to reduce the number of their sexual partners, to avoid transmission of the mpox virus.

The antiviral TPOXX is used to treat mpox in immunocompromised people, and others at risk for serious illness.

Asked about isolation guidelines, Janssen said, “Each individual will have different symptoms, so we recommend people talk to their health care providers about specific isolation guidelines.”

Updated, 8/15/25: This article has been updated with comments from the San Francisco AIDS Foundation.
Updated, 8/19/25: This article has been updated with comments from the San Francisco Department of Public Health.
Updated, 8/20/25: This article has been updated with more concise information on getting mpox vaccinations.