Will new type of mpox virus spread beyond California? Many at-risk people aren’t vaccinated.
October 22, 2025
California’s confirmation of locally transmitted Clade I mpox cases is a serious reminder that vigilance against emerging infections cannot wane. Despite widespread vaccine availability, fewer than half of at-risk individuals nationwide are fully vaccinated, leaving significant gaps in protection. The new outbreak highlights both the danger of complacency and the value of sustained public health investment, including surveillance and global cooperation. While the risk to the general public remains low, targeted vaccination and education campaigns are urgently needed. Protecting vulnerable populations through prevention and sustained funding must remain a national priority to avoid another widespread resurgence.
California’s detection of locally transmitted Clade I mpox cases marks a troubling milestone in the nation’s public health landscape. For the first time, infections of the more virulent Clade I strain have been confirmed in the United States without international travel links, signaling possible community spread. The three cases, all hospitalized but recovering, illustrate the continuing need for vigilance even as the 2022–23 outbreak of the milder Clade II strain fades from memory.
Across the country, vaccination gaps remain wide. Data from the Centers for Disease Control and Prevention show that fewer than half of individuals at highest risk of exposure have received both doses of the JYNNEOS vaccine. Even in well-resourced jurisdictions such as California, New York City, and Washington, D.C., full vaccination rates remain below 70 percent. This lag reflects pandemic fatigue, fading awareness, and the “out of sight, out of mind” attitude described by infectious disease specialists.
The current outbreak is a stark reminder that global health threats do not respect borders. Experts have warned for months that continued transmission of Clade I mpox in Central Africa could lead to international spillover. California’s cases, while limited, demonstrate how easily such predictions can become reality. The situation also underscores the importance of maintaining investment in disease surveillance, laboratory diagnostics, and public health infrastructure, even amid government funding disruptions.
Health officials have emphasized that the risk to the general public remains low, as mpox spreads primarily through close physical contact. Yet complacency is a risk in itself. Increasing vaccination among gay, bisexual, and transgender individuals, who remain most at risk, is critical. The broader lesson is clear: sustained global and domestic public health investment is the only way to prevent isolated infections from becoming the next international emergency.