Considering the virulence of mpox clade I that has been ongoing internationally, the CDC has provided information to both US
Image credit: CDC
The Centers for Disease Control and Prevention has put out a health alert to travelers to the Democratic Republic of Congo (DRC) or other countries with sustained spread of clade I mpox, regardless of sexual orientation or gender identity. The federal agency said travelers should be made aware of activities associated with cases and should be vaccinated with 2 doses of the Bavarian Nordic MVA-BN (Jynneos) mpox vaccine if they anticipate certain sexual exposures while traveling. Additionally, CDC offers guidance for US clinicians to provide their patients.
What You Need to Know
Travelers to the Democratic Republic of Congo (DRC) and surrounding regions should be aware of the increased risk of Clade I mpox, which is more severe and transmissible compared to Clade II.
The CDC recommends the two-dose JYNNEOS mpox vaccine for travelers anticipating sexual activity in countries with ongoing Clade I transmission.
Travelers should avoid close contact with individuals showing symptoms of mpox and contaminated materials, particularly in sexual settings. While mpox is not spread through casual contact, sexual activity and close interactions carry a higher risk.
Clade I and Clade II Differences
Mpox has 2 distinct genetic clades I and II, (subtypes of MPXV), which are endemic to central and west Africa, respectively. Clade I mpox has previously been observed to be more transmissible and to cause a higher proportion of severe infections than clade II. The ongoing global mpox outbreak that began in 2022 is caused by clade II, which is not as deadly as its clade I counterpart, as WHO noted in its May 2024 strategic framework.2
It is very important to make the distinction that the ongoing outbreak in Africa specifically around the DRC is related to clade I. Thus far in the US, the American CDC says there are no cases of clade I in the country, and that the risk to people in the United States is low.3
For Clinicians With Patients Traveling to These Areas
CDC provided information and resources to US clinicians who are either planning on traveling to these areas or have traveled recently to them. Travelers to these countries should begin by having a conversation with their providers and review the information below to get a better understanding and reduce the risk of infection.
For travel health visits, the federal agency says clinicians should consider the following when interacting with patients:
- Discuss mpox prevention and risk reduction strategies with all travelers to countries with ongoing human-to-human transmission of clade I MPXV. Currently, these countries include Burundi, CAR, DRC, ROC, Rwanda, and Uganda. Note that ongoing transmission is not necessarily occurring in every country reporting mpox cases. An updated list of the countries with ongoing spread of clade I MPXV is available on the CDC website.
- Discuss patients’ sexual history and travel plans, including if patients anticipate any sexual activity during travel. Up to one in three travelers will have sex with a new partner while on a trip.
- Advise travelers that mpox exposure risk is associated with sexual contact.
- Remind patients that mpox is not spread through casual contact, such as one might have in public spaces like markets, offices, or classrooms.
- Counsel patients on activities that may increase risk for MPXV exposure and risk reduction strategies if they have plans to travel to a country where ongoing human-to-human transmission of clade I MPXV is occurring. Travelers to affected countries should:
- Avoid close contact with people who are sick with signs and symptoms of mpox, including skin or genital lesions.
- Avoid contact with contaminated materials used by people who are sick, such as clothing, bedding, toothbrushes, sex toys, or materials used in healthcare settings.
- Advise patients about the risk for mpox exposure through sexual contact (regardless of sexual orientation or gender identity) associated with clade I MPXV.
- Recommend vaccination with the 2-dose JYNNEOS vaccine series to any adult, regardless of gender identity or sexual orientation, if:
They are traveling to a country where clade I MPXV is spreading between people, AND They anticipate experiencing any of the following:
- Sex with a new partner
- Sex at a commercial sex venue, like a sex club or bathhouse
- Sex in exchange for money, goods, drugs, or other trade
- Sex in association with a large public event, such as a rave, party, or festival
- Recommend starting, if possible, the mpox vaccine series at least 6 weeks before travel begins, since two doses should be given 28 days apart and it takes 14 more days for immunity to peak.
- Emphasize risk reduction strategies in conversation with patients who are not eligible for vaccination, or who do not present in time to receive the two recommended vaccine doses 28 days apart
- Advise patients that two vaccine doses are more effective than one dose.
- Two doses of JYNNEOS can prevent mpox and may reduce the severity of symptoms in people with mpox.
- A multijurisdictional study conducted in 2022–2023 in the United States identified significant JYNNEOS vaccine effectiveness against clade IIb mpox: 75% after one dose and 86% after two doses.
- Consult CDC’s mpox vaccine finder if your facility doesn’t have mpox vaccine.
- Counsel patients who might be at risk exclusively from day-to-day household contact or patient care about risk reduction strategies other than vaccination.
- Continue to follow CDC’s current vaccine guidance to prevent clade II MPXV infection, which continues to circulate in the United States, and will also help protect those individuals from clade I MPXV.1
