Mpox Cases Are Rising in San Francisco Again. From Symptoms to Vaccines, What to Know for Summer 2025

San Francisco health officials have confirmed that cases of mpox are once again rising in the city.

Since late June, 14 San Francisco residents have been diagnosed with mpox, the disease formerly known as “monkeypox.” So far in 2025, the city’s average was around one case per month.

As the name suggests, mpox is related to the smallpox virus but is generally less severe and far less contagious than smallpox, according to the California Department of Public Health. In addition to fever, chills, headache and muscle pain, mpox can cause a painful rash  — also known as lesions — that appear on many parts of the body.

Anyone can get mpox, which spreads mainly through close physical contact, including sex, but past outbreaks have particularly affected gay and bisexual men, along with trans and nonbinary people who have sex with men.

The cases seen in San Francisco are all of the clade II strain of mpox, the same kind that caused an outbreak in the Bay Area in 2022 and that’s been circulating at low levels since.

Here’s what we know about the current rise in Bay Area mpox cases, how mpox spreads, what symptoms to be aware of and who should get an mpox vaccine.

Jump straight to:

• Who’s eligible for an mpox vaccine in the Bay Area?
• Who is most at risk now from mpox?

What are the symptoms of mpox?

What’s happening with the summer 2025 mpox cases in San Francisco?

Since the 2022 outbreak of clade II mpox, the virus has been circulating at low levels in the Bay Area. From January to May,  the average mpox case count in San Francisco has hovered around one per month, according to the city’s Department of Public Health.

In late June, one mpox case was reported in San Francisco, rising to 10 in July. Three more cases have been confirmed so far in August.

On Thursday, SFDPH issued a health update to local providers, noting that these cases have “typically been mild, with no signs of severe infection or need for hospitalization” — but also that most 2025 cases in San Francisco had been in people who had received both doses of the mpox vaccine, Jynneos.

How does this increase compare to previous years? While current mpox cases in the city are higher than they were at this time last year and in 2023, “this increase is not a cause for alarm, as it’s small,” said Dr. Julia Janssen, deputy director of SFDPH’s HIV/STI Prevention and Control Branch.

“We often see an increase in mpox cases in the summer and fall starting since 2022,” she said. And since 2022, SFDPH has conducted increased awareness campaigns around mpox and mpox vaccinations ahead of big annual gatherings such as San Francisco Pride in late June and Folsom Street Fair in September. The agency says this regular summer and fall increase in cases “may be associated with larger events and summer and fall gatherings.”

If these 2025 mpox cases are in people who’ve been vaccinated, should I still even seek out a vaccine?

Yes, says SFDPH.

Firstly, while fewer than 1% of people who are fully vaccinated have been diagnosed with the disease, “no vaccine is 100% effective,” said Janssen. “And while mpox infection after vaccination is rare, it does occur.”  Like the COVID-19 vaccine, the mpox vaccine can’t prevent all infections.

But even if someone who’s fully vaccinated with Jynneos does get infected with mpox,  she said, “those cases are typically mild.”

In other words: Like the COVID-19 shot, the mpox vaccine makes it far more likely that any infection you get is far less severe than it would have been if you hadn’t been vaccinated.

“I think what’s most important here is that the vaccine reduces the risk of infection and offers really strong protection against severe illness, hospitalization and death,” she said.

And the difference between suffering from severe mpox versus a mild case can be considerable, as attested to by the “excruciating” symptoms reported during the early days of the 2022 U.S. outbreak, when most patients hadn’t yet been offered the mpox vaccine. Janssen confirmed that during the Bay Area’s initial surge back then, before the widespread Jynneos vaccination campaign, “the illness severity was different from what we see now.”

Jump to where to find an mpox vaccine. 

I’ve already got my mpox vaccine. Should I seek out a booster now?

No, said SFDPH’s Janssen: “Booster doses are not recommended” for the mpox vaccine.

Aren’t there several kinds of mpox?

Yes, there are two types of mpox: clade I, which is more severe, and clade II.

The cases currently being seen in San Francisco are all clade II mpox, the less severe strain.

The 2022 mpox outbreak in the United States — which particularly affected gay and bisexual men, as well as trans and nonbinary people who have sex with men — was also caused by clade II mpox. Read more about the 2022 outbreak.

In August 2024, the World Health Organization declared a series of clade I mpox outbreaks in Congo and elsewhere in Africa a global emergency, with thousands of cases of sickness and even death confirmed among children and adults in many countries.

The clade I strain that spread in eastern and central Africa “primarily affects heterosexual people and children within households,” UCSF infectious disease expert Dr. Peter Chin-Hong told KQED in 2024. However, this exposure within a home has to be “intensive.”

Only five known clade I cases have been detected in the U.S., with the first case found in San Mateo County in 2024. The most recent U.S. clade I mpox case was found in Massachusetts in June of this year.

All of these cases were from people who traveled to affected countries in Africa, according to the WHO, and no further clade I spread has been detected.

What should I know about the symptoms of mpox?

Mpox spreads through physical contact

The mpox virus spreads through close — usually skin-to-skin — contact with someone who is infected. This could be direct contact with the infectious rashes or scabs someone with mpox develops, scabs, having intimate physical contact with someone who has mpox, such as kissing, cuddling or sex.

Coming into contact with infected bodily fluids or items that have been touched by rashes or fluids from an infected person can also expose you to the virus.

In 2024, UCSF’s Chin-Hong issued a reminder that infection still “requires close skin-to-skin contact or intensive household contact — so you can’t get it from Muni or from yoga, or from going to Trader Joe’s.”

“It’s still very hard to get mpox, even from somebody with active lesions,” he said.

Mpox symptoms don’t start straight away after exposure

Mpox can have a long incubation period — that is, the time between when you’re exposed to mpox and when you start to develop symptoms.

This period can range be as short as three days and as long as 17 days (almost three weeks), according to the CDC.

Mpox symptoms and affected areas can be varied

The symptoms of clade I and clade II mpox are similar, SFDPH’s Janssen said, and they can often start as flu-like conditions — which is worth bearing in mind as the Bay Area experiences another COVID-19 wave.

The mpox virus also appears as a rash or sores or spots that can resemble pimples or blisters on the skin anywhere on the body, including the face, inside the mouth, hands, feet, chest, genitals and anus. These spots often start as red, flat spots that then become bumps before the bumps become filled with pus and turn into scabs when they break. These symptoms can be extremely painful.

If you’re unsure about recognizing an mpox rash, the CDC has a photo guide.

If you suspect you might have mpox symptoms — even if they’re subtle — see your health care provider right away or consult one of SFPDH’s clinics for mpox testing. See more on what to do if you suspect you have mpox.

Who’s eligible for an mpox vaccine in the Bay Area?

The vaccine currently available in the U.S. (brand name: Jynneos) is a two-dose series, with roughly a month between doses. Maximal immunity will build two weeks after your second dose. If you only got one dose previously, go ahead and seek out your second dose ASAP.

In 2024, the U.S. Department of Health and Human Services said in a statement that people who have received both doses of the mpox vaccine — along with people who have already had clade II mpox — “are expected to be protected against severe illness from clade I mpox” as well.

The CDC recommends the two-dose mpox vaccine to gay and bisexual men and other men who have sex with men, as well as transgender, nonbinary or gender-diverse people who in the past 6 months, have had, or anticipates having:

• More than one sexual partner and/or
• A new diagnosis of one or more sexually transmitted infections.

The CDC’s vaccine recommendations also include anyone who has had sex at a commercial sex venue like a sex club or bathhouse. See the full mpox vaccine eligibility recommendations from the CDC.

San Francisco additionally recommends vaccination for anyone living with HIV, anyone taking PrEP or who’s eligible to take it and sex workers. SFDPH also recommends it for anyone who has sex “at a large event in a geographic area where mpox virus transmission is occurring, or has a sex partner with any of the stated risks,” said Janssen.

Travel and mpox vaccination

The CDC has updated its vaccination recommendations to extend to people traveling to countries with clade I and clade II outbreaks. As of Aug. 15 these countries with clade I outbreaks include Burundi, Central African Republic, Democratic Republic of the Congo, Ethiopia, Kenya, Malawi, Mozambique, Republic of the Congo, Rwanda, South Sudan, Tanzania, Uganda, and Zambia. Countries with new clade II outbreaks include Liberia and Sierra Leone.

The agency recommends getting both doses of the vaccine “if you anticipate experiencing any of the following” while traveling to these countries:

• Sex with a new partner
• Sex at a commercial sex venue, such as a sex club or bathhouse
• Sex in exchange for money, goods, drugs or other trade
• Sex in association with a large public event, such as a rave, party or festival.

The mpox vaccine was also originally only available for people aged 18 and older, but in 2022 the Food and Drug Administration (FDA) issued an emergency-use authorization that allows providers to also give the vaccine to young people under 18 who are “determined to be at high risk” of infection.

Where can I find an mpox vaccine?

If you have a regular health care provider, SFDPH recommends you ask them first about getting the mpox vaccine. Your vaccine will be free, but you may be charged a regular copay for seeing your provider.

If you’re eligible for the vaccine, your health insurance should cover the costs thanks to the CDC’s recommendations. If you don’t have a regular health care provider or insurance, you can find the mpox vaccine free at clinics around the Bay Area. You can opt to schedule an appointment or choose a walk-in clinic, depending on what works best for you.

(As with the COVID-19 vaccine, receiving an mpox vaccine won’t make you a public charge or affect any future immigration processes you may enter into, and you won’t be asked about your immigration status to receive the mpox vaccine.)

If you live in or near San Francisco:

See a full list of mpox vaccine sites near you in San Francisco. SFDPH confirms that you don’t have to be a city resident in San Francisco to get vaccinated for mpox.

Mpox vaccination sites elsewhere in the Bay Area and California:

Find an mpox vaccine clinic near you using the state’s myturn.ca.gov site.

Getting an mpox vaccine at a pharmacy:

Some pharmacies offer mpox vaccination appointments online, along with other vaccines like COVID-19 and flu. But if you choose this route, you’ll be asked for insurance details — and it’s important to verify with your insurer ahead of time that they’ll cover the cost of an mpox vaccine at a pharmacy like CVS or Walgreens, as the out-of-pocket costs you’ll be quoted may be steep. If you find your insurance doesn’t fully cover the cost, SFDPH said you can seek your vaccine at one of their clinics while supplies last.

If you get your health care through a health system like Kaiser Permanente, it’s unlikely you’ll be able to get your mpox vaccine covered by insurance at a pharmacy like CVS or Walgreens — the way you can’t get your COVID-19 or flu shot covered by Kaiser at a pharmacy either — and may have to seek it directly from a Kaiser provider.

If you’re able to make an appointment online at a pharmacy for your mpox vaccine, you should consider calling that location ahead of time to verify that they do indeed have supply in stock.

This story includes reporting from KQED’s Billy Cruz, Carlos Cabrera-Lomelí and Nisa Khan.