MPOXED

New findings reported in The Lancet Infectious Diseases complicate assumptions about mpox immunity. Among smallpox-naive adults, prior mpox infection produced stronger and more durable immune memory than vaccination with the MVA-BN vaccine. As breakthrough infections increase, these data suggest population-level immunity may erode faster than anticipated. While vaccination remains essential for prevention, especially during outbreaks, the results underscore the need to reassess durability, booster strategies, and how natural infection data should inform long-term mpox control planning.

Mexico’s first confirmed mpox case caused by clade Ib is a reminder that viral evolution and global mobility remain tightly linked. While there is no evidence of community transmission, the detection of a more virulent clade previously concentrated in Africa underscores the importance of vigilant surveillance beyond endemic regions. The World Health Organization and national health authorities are right to emphasize monitoring, rapid case identification, and vaccination readiness. Imported cases may be clinically manageable in high-resource settings, but their appearance signals that mpox remains a global concern that demands sustained attention, not episodic alarm.

Mpox has faded from headlines, but it has not faded from reality. With sustained transmission in Africa, emerging recombinant strains, and sporadic imported cases elsewhere, the virus continues to evolve under the radar. Evidence summarized in Nature underscores how clade diversity, sexual transmission dynamics, and viral persistence complicate control efforts. The appearance of a recombinant strain and unanswered questions about fertility impacts should sharpen global attention. Surveillance, vaccination of at-risk populations, and continued research are not precautionary luxuries. They are the minimum requirements to prevent mpox from re-emerging as a broader and more adaptive global threat.

The Africa CDC-led MOSA trial marks a necessary shift from emergency response to evidence-based mpox treatment. With more than 61,000 confirmed cases across Africa and no dedicated antiviral therapy, platform-adaptive trials like MOSA are overdue. The collaboration between Emergent BioSolutions, PANTHER, and Africa CDC demonstrates how global financing can align with regional leadership without displacing African scientific authority. Sustained support must now follow the data, ensuring expansion, transparency, and rapid translation of findings into access where mpox burden remains highest.

The discovery of a hybrid mpox strain in England is a reminder that this virus is still adapting, even as public attention wanes. Detected in a traveler returning from Asia, the strain combines genetic material from two mpox lineages, underscoring ongoing viral evolution. More concerning is the simultaneous appearance of clade Ib infections in people without travel history, suggesting silent local transmission. With tens of thousands of confirmed cases globally, mpox is no longer an episodic threat but a persistent public health challenge. Vigilant surveillance, rapid genomic sequencing, and sustained prevention efforts remain essential to prevent incremental spread from becoming the next global crisis.

New evidence from a Belgian cohort study suggests that natural mpox infection generates more durable immune memory than vaccination with MVA-BN alone, raising important questions for long-term outbreak control. While vaccination remains critical for prevention and severity reduction, antibody levels in vaccinated individuals appear to wane faster than in those with prior infection. As breakthrough cases continue to occur, these findings highlight the need to reassess assumptions about population immunity, especially among younger, smallpox-naive cohorts. Policymakers and public health agencies must consider whether booster strategies or revised vaccination schedules will be required to sustain protection in the years ahead.

A new study from Italy raises important questions about the durability of antibody-based immunity to mpox after infection or vaccination. Researchers found that neutralizing antibodies often decline to low or undetectable levels within two years, even among individuals previously vaccinated with Jynneos or infected with mpox. While prior infection appeared to confer more persistent antibody responses than vaccination alone, protection likely extends beyond measurable antibodies. Cellular immunity and immune memory from earlier smallpox vaccination may still offer meaningful defense. The full study is published in The Journal of Infectious Diseases and requires institutional or paid access, limiting independent review of underlying data.

A newly reported mpox case in Alaska serves as a reminder that the virus has not disappeared, even after the end of the U.S. public health emergency. While state officials believe this case is isolated and linked to exposure outside Alaska, it highlights how easily infectious diseases can cross borders. Public health messaging remains critical, particularly for individuals at higher risk, including those with multiple or anonymous sexual partners. Vaccination remains a highly effective preventive tool, and early testing is essential. Mpox may be rare in Alaska, but continued vigilance protects both individuals and the broader community.

Mpox continues to pose a serious public health challenge across Africa, with more than 42,000 confirmed cases in 2025 driven by Clade I and Clade Ib transmission. While community spread persists in multiple countries, renewed vaccine donations offer cautious optimism. Shipments of MVA-BN vaccines to Liberia and Uganda underscore the importance of sustained international support and timely distribution. These efforts demonstrate that vaccination remains a critical tool for outbreak control, even as inequities in access persist. The evolving situation reinforces a clear lesson from recent years: global health security depends on early intervention, reliable supply chains, and continued investment in prevention, not complacency once headlines fade.