In order to mitigate the spread of monkeypox, the US Department of Health and Human Services (HHS) is expanding access to Jynneos (smallpox and monkeypox vaccine, live, nonreplicating), a vaccine indicated for prevention of smallpox and monkeypox disease in adults 18 years of age and older determined to be at high risk for smallpox or monkeypox infection.

Jynneos is a live vaccine produced from the strain Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN), an attenuated, nonreplicating orthopoxvirus; this modified form of the vaccinia virus does not cause disease in humans and cannot reproduce in human cells. 

Under the enhanced nationwide vaccination strategy, HHS will provide 296,000 doses of Jynneos vaccine; 56,000 doses will be made available immediately, while the other 240,000 doses are expected in the coming weeks. Over the summer, an additional 750,000 doses will be made available, with more doses expected in the fall. In total, 1.6 million doses of the vaccine will be available this year.

Doses will be distributed to areas with the highest case rates of monkeypox. The allocation system will also take into account the number of individuals at risk for monkeypox who also have pre-existing conditions such as HIV. According to HHS, ACAM2000, a licensed smallpox vaccine, may also be requested; however, due to its side effects, it is not recommended for all individuals.

Jynneos is administered by subcutaneous injection as 2 doses (0.5mL each) 4 weeks apart. Each vial contains a single dose (0.5mL).

“While monkeypox poses minimal risk to most Americans, we are doing everything we can to offer vaccines to those at high-risk of contracting the virus,” said HHS Secretary Xavier Becerra. “This new strategy allows us to maximize the supply of currently available vaccines and reach those who are most vulnerable to the current outbreak.” 

The Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices currently recommends vaccination for high risk individuals following a confirmed case of monkeypox exposure; however, the current outbreak has made it difficult to identify all contacts. As such, the vaccine will be provided to all individuals with confirmed or presumed exposure.

“We are focused on making sure the public and health care providers are aware of the risks posed by monkeypox and that there are steps they can take, through seeking testing, vaccines and treatments, to stay healthy and stop the spread,” said CDC Director Rochelle Walensky, MD, MPH.

The CDC recently activated its Emergency Operations Center in response to the monkeypox outbreak, providing additional personnel and resources to focus on monitoring and coordinating the emergency response.

Testing capacity has also been expanded to 5 commercial laboratory companies that include Aegis Science, Labcorp, Mayo Clinic Laboratories, Quest Diagnostics and Sonic Healthcare. The agency recently updated and expanded its monkeypox case definitions to encourage testing among individuals presenting for care with relevant history, signs and symptoms.


  1. HHS announces enhanced strategy to vaccinate and protect at-risk individuals from the current monkeypox outbreak. News release. June 28, 2022.
  2. Jynneos. Package insert. Bavarian Nordic A/S; 2021. Accessed June 30, 2022.