Last week, the World Health Organization (WHO) announced they had developed a guide to aid health authorities, communities and interested stakeholders in preventing and controlling mpox outbreaks. Specifically, it helps in creating a roadmap in every context, advance mpox research and access to countermeasures, and to minimize zoonotic transmission.
Mpox is a viral illness caused by the monkeypox virus (MPXV). It can cause a painful rash, enlarged lymph nodes and fever. Most people fully recover, but some get worse and deal with a severe infection, which can lead up to death. The virus transmits from person to person through close contact, including sexual. It also has animal reservoirs in east, central and west Africa, where spillovers from animals to humans can occasionally occur, sparking further outbreaks.1
Differentiating Outbreaks
According to WHO, there are 2 different clades of the virus: clade I and clade II. Clade I outbreaks are deadlier than clade II outbreaks.1
A major emergence of mpox linked to clade II began in 2017, and since 2022, has spread to all regions of the world. Between July 2022 and May 2023, the outbreak was declared a Public Health Emergency of International Concern. While that outbreak has largely subsided, cases and deaths continue to be reported today, illustrating that low-level transmission continues around the world.1
What You Need to Know
The World Health Organization (WHO) has released a guide to help health authorities, communities, and stakeholders prevent and control mpox outbreaks.
Mpox has two clades, clade I and clade II, with clade I being more deadly. A significant global outbreak linked to clade II began in 2017 and became a Public Health Emergency of International Concern between July 2022 and May 2023. Meanwhile, a major outbreak of clade I is ongoing in the Democratic Republic of the Congo (DRC), with over 6500 cases and 345 deaths reported this year.
The Jynneos vaccine has shown 98.2% efficacy against mpox infection. Despite this, a recent cluster in Chicago saw cases among fully vaccinated individuals, likely due to behaviors associated with transmission. The Jynneos vaccine is now available for commercial purchase in the US, enhancing access through pharmacies, physician offices, and public health clinics.
Currently, there is also a major outbreak of clade I virus in the Democratic Republic of the Congo (DRC), where cases have been on the rise for decades. Since the beginning of the year, over 6500 cases and 345 deaths have been reported in the DRC. Almost half of these are among children under the age of 15 years.1
In the spring of 2023, the city of Chicago had an Mpox cluster amongst fully vaccinated (FV) individuals. During this outbreak, from March 18-June 27, 2023, investigators identified 49 mpox cases with 57% of these cases coming from fully vaccinated individuals.2
“Our investigation indicated that cases were likely due to frequent behaviors associated with mpox transmission, even with relatively high vaccine effectiveness and vaccine coverage. Cases after vaccination might occur in similar populations,” the investigators concluded.2
It was not determined, which Clade this was, but it is definitely concerning to public health officials as to the nature of positive cases in fully vaccinated individuals.
Mpox Vaccination Effectiveness
It is important to note that in the same report about the Chicago outbreak in last week's MMWR, investigators found the mpox vaccine, Jynneos, (Bavarian Nordic), was 98.2% efficacious against infection.2 The vaccine is FDA approved, and last month, Bavarian Nordic announced the Jynneos vaccine was available for commercial purchase in the US. Health care providers can order the vaccine through wholesalers and distribution partners, making it accessible at pharmacies, physician offices, and public health clinics.2
To learn more about the WHO strategic framework, interested parties can go here.
References
1. WHO releases a strategic framework for enhancing prevention and control of mpox. WHO news statement. May 24, 2024. Accessed May 27, 2024.
https://www.who.int/news/item/24-05-2024-who-releases-a-strategic-framework-for-enhancing-prevention-and-control-of-mpox
2. Parkinson J. Mpox Vaccine is 98.2% Efficacious Against Infection. Contagion. May 23, 2024. Accessed May 27, 2024.
https://www.contagionlive.com/view/mpox-vaccine-is-99-2-efficacious-against-infection
