The Current State of Monkeypox Vaccination|eMedEvents

 Monkeypox is a viral zoonosis belonging to the Orthopoxvirus genus, which means it is closely related to smallpox. Following its initial discovery in the 1950s and the first recorded human case in the 1970s, there have been sporadic outbreaks of monkeypox in the decades since. However, the ongoing outbreak that began in May 2022 marks the first time the virus has spread to such an extent outside of its endemic countries in Africa.

Monkeypox is highly contagious. Anyone can contract the virus, should they come into close physical contact with an infected person or animal. Its modes of transmission involve contact with the rash—including skin-to-skin contact and indirect contact through the handling of linens, items, or surfaces that have been soiled by monkeypox lesions—and exposure to respiratory droplets.

While originally designed to combat smallpox, there are presently two vaccines that have been approved for monkeypox prevention and treatment:

1. JYNNEOS — Approved by the FDA for monkeypox prevention, this is the primary vaccine available in the U.S. at this time.
2. ACAM2000 — Approved for immunization against smallpox, ACAM2000 was made available for monkeypox prevention under an Expanded Access Investigational New Drug (EA-IND) protocol issued by the FDA.

Following exposure to the virus, individuals—particularly those who are immunocompromised or otherwise high risk—can receive vaccination to help prevent the monkeypox disease from developing.

Bear in mind that the presumed effectiveness of these vaccines has been determined based on observational studies of their use against smallpox. Their efficacy against the ongoing monkeypox outbreak is currently unknown; the WHO urges those who have been vaccinated to continue to protect themselves by avoiding close physical contact with someone who has monkeypox.

JYNNEOS

JYNNEOS is a two-dose, live virus vaccine that contains Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN), which is a weakened, non-replicating orthopoxvirus. Individuals who are at exceptionally high risk for contracting monkeypox will often be administered JYNNEOS over ACAM2000.

This vaccine is administered subcutaneously (beneath the skin), with each dose 28 days apart. A person is considered fully vaccinated 14 days following their second dose. When receiving JYNNEOS, not everyone will experience side effects; the most common are redness and itchiness at the injection site, headache, fatigue, nausea, chills, and muscle aches.