The Centers for Disease Control and Prevention has identified four presumptive and one confirmed cases of monkeypox in the United States, and public health officials expect physicians to diagnose more Americans with the virus in the coming days.

Unlike COVID-19, a novel disease that took the country by surprise and by storm, the U.S. has dealt with monkeypox outbreaks in the past and has vaccines and therapeutics on hand that can treat the virus and prevent serious illness. As cases ramp up, the Biden administration is working on releasing vaccines and treatments from the Strategic National Stockpile so physicians can use them as needed.

The four presumptive cases include one individual from New York City, one from Florida, and two from Utah. Last week public health officials confirmed a case in Massachusetts. Those who have tested positive for orthopox infection are considered to have a presumed case. The CDC must conduct final testing for monkeypox.

“I want to emphasize that we’re in the early days of this response. It’s likely that there are going to be additional cases reported in the United States,” Jennifer McQuiston, a deputy director of the CDC’s National Center for Emerging and Zoonotic Diseases, told reporters Monday.

Cases of monkeypox, smallpox’s less infectious, less deadly cousin, have been popping up around the world over the last two weeks. These recent cases are different than previous monkeypox outbreaks because most cases do not involve any recent travel to Nigeria or to another country where the virus is normally found.  

The virus is characterized by a painful skin rash and is spread by close contact with another infected person or respiratory droplets. So far, most cases have been among men who have sex with other men.

John Brooks, CDC chief medical officer to for HIV and AIDS prevention, warned that anyone with a rash around their genital area should get checked out for monkeypox. It is often spread through sexual contact, and right now the LGBTQ community is especially at risk.

The current goal is to limit spread in communities where monkeypox is occurring, and anyone who has been in close contact with an infected person or has a suspected infection should isolate, the officials said.

Vaccines and therapeutics

The U.S. can use the mechanisms it has prepared for its smallpox response to respond to monkeypox, McQuiston and Brooks said.

There are two available vaccines to treat monkeypox soon after exposure.

There have been requests for the release of the JYNNEOS vaccine from the Strategic National Stockpile already for some of the high-risk contacts. JYNNEOS is a two-dose vaccine that the U.S. currently has about 1,000 doses of, but the company is ramping up production. Because it is a newer vaccine, the CDC does not have a lot of data, but animal trials show it is effective.

The other vaccine, ACAM2000, is a little more dangerous and has significant side effects, but the U.S. has more than 100 million doses. This vaccine has been proven to be effective in preventing disease if given to a patient soon after exposure.

Two antivirals have been approved for smallpox, TPOXX and TEMBEXA. The CDC holds expanded access to new drug protocol to use TPOXX to treat monkeypox. The agency is developing treatment guidance for clinicians and public health authorities to determine who should receive TPOXX.

The other drug, TEMBEXA, has also been licensed for the treatment of smallpox, and the CDC is currently developing an emergency access new drug protocol so it can also be used to treat monkeypox.

The Biden administration is negotiating with the TEMBEXA manufacturers, Chimerix, to procure this drug for the Strategic National Stockpile.

The federal government is taking the monkeypox outbreak seriously but does not expect it to have a major impact on Americans’ day-to-today lives. Brooks said that at the present time, spread isn’t occurring very rapidly and the CDC would not recommend shutting down in-person events.

“I don’t think that there’s a great risk to the general community from monkeypox right now in the United States. I think that we need to pay close attention to the communities in which this might be circulating so that we can communicate effectively with them and help bring this outbreak under control,” McQuiston said.