SAN FRANCISCO (KRON) — California became the latest to declare an emergency over monkeypox, following Illinois and New York. The nation’s rising case count – over 5,800 cases as of Monday night, the Centers for Disease Control and Prevention shows – has many wondering how the disease is spreading.

That’s especially true in San Francisco amid large gatherings, like the three-day music and arts festival Outside Lands that kicks off this weekend.

Dr. Peter Chin-Hong, infectious disease expert with the University of California San Francisco, broke it down into three levels of risk when it comes to the spread of monkeypox: high, medium and low. He credits the vaccine with being able to put more people in the low-risk group. 

Prolonged skin-to-skin contact is the most common – and thus, high-risk – way that monkeypox is spread, according to Chin-Hong. “Intimate contact is very efficient because you’re making little cuts in the skin with the person who’s not infected and the virus from the open sore can enter very easily.”

Another way that monkeypox is spread is through shared bedding and clothing. It’s not as likely, but still possible. “Usually with someone who’s had an open lesion, slept in the bedding, and then it survives in that way with a high load, so I would call that … maybe medium,” said Dr. Chin-Hong.

He said monkeypox can only be spread from the time someone feels sick to the time their rash scabs off. Casual interactions such as a simple handshake are low-risk that would require very specific scenarios for spread.

“You could be shaking somebody’s hand, have a cut in your hand and the person has an open sore and they didn’t know it, or recognize it — that’s possible,” said Chin-Hong.

As far as events like Outside Lands, the doctor is more concerned about what happens behind closed doors than among those gathering in Golden Gate Park. “Risky activities are not in Outside Lands. It’s in the events or the intimate settings that people have or encounters they have after the event,” said Chin-Hong.

Dr. Chin-Hong said the vaccines that have been and continue to be administered will be a game-changer with monkeypox. He said the shot will abort the disease completely if taken within the first four days of being infected.

Scientists say that unlike campaigns to stop COVID-19, mass vaccinations against monkeypox won’t be necessary. They think targeted use of the available doses, along with other measures, could shut down the expanding epidemics that were recently designated by the World Health Organization as a global health emergency.

President Joe Biden is set to name top officials from the Federal Emergency Management Agency and the CDC – Robert Fenton and Dr. Demetre Daskalakis, respectively – to serve as the White House coordinators to combat the growing monkeypox outbreak on Tuesday. The White House said the pair would coordinate “strategy and operations to combat the current monkeypox outbreak, including equitably increasing the availability of tests, vaccinations and treatments.”

The Associated Press contributed to this report.