2022 Mpox Outbreak in Washington

In May 2022, the World Health Organization (WHO) reported multiple cases of mpox (formerly known as monkeypox) in countries where the disease was not regularly occurring. This outbreak, unlike previous mpox outbreaks in the past, was primarily driven by transmission through close sexual and intimate contact, which disproportionately but not exclusively affected men who have sex with men (MSM).

In late May, the Washington State Department of Health (DOH) was notified of the first case of mpox in a King County resident. Public Health Seattle and King County (PHSKC) responded by creating a testing site at their Sexual Health Clinic, which later became a main site for vaccine administration as well. Cases of mpox steadily rose until they peaked in late July of 2022 at around 275 total cases and steadily declined.

Case investigations conducted by local health jurisdictions and DOH prioritized linking people with mpox to medical care and notifying close contacts to link them to post-exposure prophylaxis vaccination.

In 2022, a total of 654 cases were reported. The majority of these cases were residents of King County (76.9%), identified as male (94.1%), between the ages of 25-44 (68.3%), and disproportionately from communities of color. Fortunately, this outbreak resulted in less severe cases of mpox resulting in less than 3% of cases requiring hospitalization and 0 total deaths in Washington.

On June 2022, the JYNNEOS vaccine was allocated to Washington state for use as post-exposure prophylaxis for close contacts of mpox cases. On August 3rd of 2022, Washington state then adopted a post-exposure prophylaxis vaccination strategy (known as PEP++) to vaccinate individuals who were at highest risk of acquiring mpox.

PHSKC and DOH Care-a-Van worked with community organizations and local health jurisdictions to host various community vaccination events that prioritized communities and areas that have been disproportionately affected by this outbreak. In 2022, the total number of doses of JYNNEOS vaccine administered in Washington was estimated to be 30,115 doses. Following the 2022 outbreak, JYNNEOS vaccine continued to be administered in Washington state.

On January 31, 2023, the Public Health Emergency declaration under the Public Health Service Act for mpox expired as case counts continued to remain low and consistent. The decline of mpox cases could be attributed to variety of factors, but it's notable that affected communities, such as the LGBTQ+ community, stepped up, changed behaviors, and sought vaccination to prevent further spread.

Outbreak Specific Messaging