(NEXSTAR) – As the number of monkeypox cases confirmed in the U.S. approaches 6,000, the Centers for Disease Control and Prevention recommends people at high risk of contracting the virus seek out a vaccine. But getting vaccinated against monkeypox isn’t as easy as heading over to your local pharmacy.

While we’ve long had a vaccine effective against the virus, its supply is currently limited. There aren’t any mass vaccination campaigns happening nationally, nor is there an easy online way to track down a dose near you.

The CDC tells Nexstar people interested in getting vaccinated against monkeypox should talk to their doctor or their state health department to find out where the vaccine is available locally.

Every state and local health department is doing things a little differently. San Francisco has set up a walk-in clinic where they give out doses to eligible people until they run out. Chicago has distributed doses to health care clinics that serve high-risk populations, and the city encourages people to reach out to the list of providers directly. Other cities and counties don’t even have any doses on hand.

The CDC says the United States currently has limited supply of the two-dose JYNNEOS vaccine, also known by the names Imvamune or Imvanex, but the White House says it’s working to distribute more.

Because supply is so limited, health authorities are limiting access to people deemed at highest risk. The criteria may vary county by county, but the CDC says you should seek a vaccine if:

• You’ve been around someone with monkeypox and have been identified as a “contact” by public health officials
• One of your sexual partners from the past two weeks has a confirmed case
• You’ve had more than one sexual partner in the past two weeks in an area with known monkeypox transmission
• Your job exposes you to orthopox viruses

New York and California have reported the most cases so far, but nearly every state has seen at least one confirmed case, according to CDC data.