In a concerning development, the number of mpox cases in the United States is now twice as high as it was at this time last year, prompting experts to stress the critical importance of enhancing vaccination coverage to mitigate transmission risks. According to data from the U.S. Centers for Disease Control and Prevention (CDC), there have been 511 reported cases of mpox this year through March 16, compared with fewer than 300 cases during the same period in 2023.

While the current transmission rates are still significantly lower than the peak levels observed in 2022, which saw tens of thousands of mpox cases in the U.S., the nation is now at increased risk due to various factors. The expiration of the public health emergency over a year ago has limited the availability of federal resources to manage the response to public health threats. Additionally, relatively low vaccination rates leave many individuals vulnerable to the virus.

In an alarming development, the CDC issued a health alert in December regarding a more transmissible and severe subtype of the mpox virus. Although this specific genetic clade has not yet been identified in the U.S., it is rapidly spreading in the Democratic Republic of Congo. Dr. Marcus Plescia, chief medical officer for the Association of State and Territorial Health Officials, highlighted the significance of mpox having an effective vaccine, unlike other infectious diseases such as syphilis, gonorrhea, chlamydia, or HIV. However, he also noted that there is still a long way to go in terms of vaccinating the at-risk population, which could lead to further outbreaks and increased case numbers.

Mpox, formerly known as monkeypox, is a less severe relative of the eradicated smallpox virus and spreads through close personal contact. Initial symptoms resemble those of the flu, including fever, chills, exhaustion, headache, and muscle weakness, followed by a rash with raised lesions that scab over and resolve over several weeks. While the virus can affect anyone, men who have sex with men and individuals with HIV are particularly at risk and may experience more severe outcomes, potentially leading to death.

The mpox vaccine, known as Jynneos and manufactured by Danish company Bavarian Nordic, requires a recommended two-dose regimen, with the shots administered about a month apart. However, CDC data shows that in most states, less than a quarter of the at-risk population has completed the two-dose series since the vaccine was authorized for emergency use in August 2022. Coverage is particularly low, below 10%, in eight states, while the District of Columbia leads with 68% coverage.

According to CDC data, nearly all regions in the U.S. have reported more mpox cases in the first three months of this year compared to the same period in 2023, with the mid-Atlantic region, specifically New York City, experiencing the largest difference. In response to a recent rise in cases in Virginia, the state health department issued a notice to raise awareness, stating that the number of cases this year has already matched the total for 2023. Among the 12 reported cases, four required hospitalization, and none of the individuals had been vaccinated.

Efforts to curb the spread of mpox necessitate a tailored and compassionate approach to reach the most at-risk populations, according to Jeffrey Crowley, director of the Infectious Diseases Initiative at Georgetown's O'Neill Institute for National and Global Health Law. One year after the initial outbreak, Crowley co-authored a report highlighting the lessons learned and actions needed to prevent a resurgence. Generating trust and forging strategic partnerships with relevant community organizations that can effectively reach high-risk individuals is crucial, he emphasized.

While previous research indicated that behavioral changes, such as reducing the number of sexual partners and one-time sexual encounters, had a significant impact on curbing mpox spread, experts stress that vaccination remains the most effective and sustainable preventive measure. Mpox vaccines do not require annual boosters, and completion of the two-dose series provides long-term coverage. Even if the more severe subtype of the virus appears in the U.S., the current vaccines available will still offer protection.

As the commercialization of mpox vaccines gradually replaces the government's management of supply, challenges may arise with regards to tracking vaccine distribution and identifying potential shortages. Elizabeth Finley, senior director of communications and prevention programs with the National Coalition of STD Directors, acknowledged the existing barriers to treatment access and the strain on the sexual health field due to budget constraints.

In conclusion, the surge in mpox cases across the United States underscores the pressing need for improved vaccination coverage. Experts emphasize the significance of proactive outreach to at-risk populations, continued public health efforts, and fostering trust to combat the spread of the virus effectively. Vigilance, prevention, and timely vaccination are vital in protecting public health and minimizing the impact of mpox outbreaks.