From May 2022 through the end of January 2023, approximately 30,000 cases of monkeypox (mpox) have been reported in the United States and >86,000 cases reported internationally.* JYNNEOS (Modified Vaccinia Ankara vaccine, Bavarian Nordic) is recommended for subcutaneous administration to persons at increased risk for mpox (1,2) and has been demonstrated to provide protection against infection (3-5). To increase the total number of vaccine doses available, the Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) on August 9, 2022, recommending administration of the vaccine intradermally (0.1 mL per dose) for persons aged ≥18 years who are recommended to receive it (6); intradermal administration can generate an equivalent immune response to that achieved through subcutaneous injection using approximately one fifth the subcutaneous dose (7). CDC analyzed JYNNEOS vaccine administration data submitted to CDC from jurisdictional immunization information systems (IIS)(†) to assess the impact of the EUA and to estimate vaccination coverage among the population at risk for mpox. During May 22, 2022-January 31, 2023, a total of 1,189,651 JYNNEOS doses (734,510 first doses and 452,884 second doses)(§) were administered. Through the week of August 20, 2022, the predominant route of administration was subcutaneous, after which intradermal administration became predominant, in accordance with FDA guidance. As of January 31, 2023, 1-dose and 2-dose (full vaccination) coverage among persons at risk for mpox is estimated to have reached 36.7% and 22.7%, respectively. Despite a steady decline in mpox cases from a 7-day daily average of more than 400 cases on August 1, 2022, to five cases on January 31, 2023, vaccination for persons at risk for mpox continues to be recommended (1). Targeted outreach and continued access to and availability of mpox vaccines to persons at risk are important to help prevent and minimize the impact of a resurgence of mpox.

Vaccination with JYNNEOS vaccine (Modified Vaccinia Ankara vaccine, Bavarian Nordic) to prevent monkeypox commenced shortly after confirmation of the first monkeypox case in the current outbreak in the United States on May 17, 2022 (1). To date, more than 27,000 cases have been reported across all 50 states, the District of Columbia (DC), and Puerto Rico.* JYNNEOS vaccine is licensed by the Food and Drug Administration (FDA) as a 0.5-mL 2-dose series administered subcutaneously 28 days apart to prevent smallpox and monkeypox infections (2) and has been found to provide protection against monkeypox infection during the current outbreak (3). The U.S. Department of Health and Human Services (HHS) allocated 1.1 million vials of JYNNEOS vaccine from the Strategic National Stockpile, with doses allocated to jurisdictions based on case counts and estimated size of population at risk (4). However, initial vaccine supplies were severely constrained relative to vaccine demand during the expanding outbreak. Some jurisdictions with highest incidence responded by prioritizing first dose administration during May-July (5,6). The FDA emergency use authorization (EUA) of 0.1 mL dosing for intradermal administration of JYNNEOS for persons aged ≥18 years on August 9, 2022, substantially expanded available vaccine supply(†) (7). The U.S. vaccination strategy focuses primarily on persons with known or presumed exposures to monkeypox (8) or those at high risk for occupational exposure (9). Data on monkeypox vaccine doses administered and reported to CDC by U.S. jurisdictions were analyzed to assess vaccine administration and completion of the 2-dose series. A total of 931,155 doses of JYNNEOS vaccine were administered and reported to the CDC by 55 U.S. jurisdictions during May 22-October 10, 2022. Among persons who received ≥1 dose, 51.4% were non-Hispanic White (White), 22.5% were Hispanic or Latino (Hispanic), and 12.6% were non-Hispanic Black or African American (Black). The percentages of vaccine recipients who were Black (5.6%) and Hispanic (15.5%) during May 22-June 25 increased to 13.3% and 22.7%, respectively, during July 31-October 10. Among 496,888 persons who received a first dose and were eligible for a second dose during the study period, 57.6% received their second dose. Second dose receipt was highest among older adults, White persons, and those residing in the South U.S. Census Bureau Region. Tracking and addressing disparities in vaccination can reduce inequities, and equitable access to and acceptance of vaccine should be an essential factor in planning vaccination programs, events, and strategies. Receipt of both first and second doses is necessary for optimal protection against Monkeypox virus infection.