Monkeypox vaccine doses being stretched to address supply issues as state updates isolation guidance

Monkeypox vaccine.

New guidance from the U.S. Food and Drug Administration makes more of the monkeypox vaccine available as a shortage of doses continues amid an outbreak of the infectious disease. 

The FDA has approved administering one-fifth of the Jynneos vaccine vial as a way to stretch the amount of available doses. 

As part of this method, the intradermal injection is administered to the front of the forearm rather than a deeper full-dose injection in the upper arm. Intradermal injection is a more shallow way of administering the dose.  

Doctors with Santa Clara Valley Medical Center spoke about the new process on Friday at a vaccine clinic in San Jose. 

"This was approved by the FDA based on a study that was done a few years ago in preparation for this exact scenario; a possible outbreak of monkeypox that would require dose sparing or stretching few doses to as many people as possible," said Dr. Jennifer Tong, associate medical chief officer for Santa Clara Valley Medical Center.

Doctors say people getting the injection this way are showing an immune response just as strong as the response people experienced after getting a full dose. 

House Speaker Nancy Pelosi hosted a San Francisco town hall on monkeypox earlier this week. The meeting addressed the vaccine shortage and the disproportionate impact of the disease on LGBTQ communities, particularly men who have sex with men.

San Francisco's health officer indicated at that time that the dosage amount of the two-dose vaccine would depend on future allocations of the vaccine. On Friday San Francico Department of Public Health confirmed they too would be shifting to the one-fifth dose to be administered through intradermal injection.

SF health officials said they will receive 1,600 doses in their next allotment, but were not specific as to when it arrives. This compares to more than 10,000 doses in their allotment, but with the new method it translates to 8,000 doses. Health officials indicate they had to agree to the new method in order to secure the allotment from federal and state authorities.

Health officials have already said they are prioritizing the first dose and would defer second doses until supply increases

Also of concern to those who called in to the town-hall meeting was the evolving isolation guidelines for monkeypox. "We consider someone transmissible with monkeypox virus, from the onset of symptoms, to until after the rash has scabbed off, fallen off, and new skin is underneath," said infectious disease expert Dr. Peter Chin-Hong of UCSF Health.

Chin-Hong warned that the virus can still be spread by sex for two to three months after any visible symptoms are gone. He advised anyone who has contracted the virus to use protection during sex.

California Department of Public Health updated their isolation guidance for the general public on Thursday. In their section on resuming normal activities, they say evidence of transmission through genital excretion is lacking and recommend condoms during sex for 12 weeks after infection. Health officials are still trying to understand if the monkeypox virus remains in semen and can be spread through sex even after lesions are healed.

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Other isolation guidance for those confirmed to have monkeypox includes wearing a well-fitting mask such as an N95, when in contact with others, until lesions have healed and 48 hours after symptoms have resolved. People confirmed to have monkeypox are being told to isolate at home and to cover their skin lesions.

There are also updated guidelines for returning to work and high-risk settings are defined. You can read the full updated state guidance here. 

San Francisco accounts for about a third of the state's confirmed and suspected monkeypox cases. As of Friday there are 638 confirmed or probable cases in the city. The U.S. currently has more than 14,000 cases. 

The walk-in vaccine clinic at Zuckerberg San Francisco General Hospital, which had once seen frustration with long lines and patients being turned away, has improved this week with no line being reported on more than one occasion. In addition, the clinic has managed to open daily until supply has been exhausted. The next available walk-in clinic is Monday, Aug. 22 through Aug. 26 from 8 a.m. to 4 p.m.