Ebola virus (EBOV) vaccine
A vaccine to prevent Ebola virus disease (EVD) is available by special request in the United States. Recombinant vesicular stomatitis virus-based Ebola virus vaccine, abbreviated as rVSVΔG-ZEBOV-GP (brand name, ERVBO) is manufactured by Merck and received approval by the FDA on December 19, 2019, for use in those ages 18 years and older. It is a live, attenuated vaccine.
The ACIP has recommended pre-exposure vaccination with rVSVΔG-ZEBOV-GP for adults 18 years or older who are at risk of exposure to EBOV while responding to an outbreak of EVD; while working as health care personnel at a federally designated Ebola Treatment Center; or while working at biosafety-level 4 facilities.10 The vaccine is protective against just 1 of 4 EBOV species, Zaire ebolavirus, which has been the cause of most reported EVD outbreaks, including the 2 largest EVD outbreaks in history that occurred in West Africa and the Republic of Congo.
It is estimated that EBOV outbreaks have infected more than 31,000 people and resulted in more than 12,000 deaths worldwide.11 Only 11 people infected with EBOV have been treated in the United States, all related to the 2014-2016 large outbreaks in West Africa. Nine of these cases were imported and only 1 resulted in transmission, to 2 people.10 The mammalian species that are suspected as intermediate hosts for EBOV are not present in the United States, which prevents EBOV from becoming endemic here.
The rVSVΔG-ZEBOV-GP vaccine was tested in a large trial in Africa during the 2014 outbreak. Its effectiveness was 100% (95% confidence interval, 63.5%-100%). The most common adverse effects were injection site pain, swelling, and redness. Mild-to-moderate systemic symptoms can occur within the first 2 days following vaccination, and include headache (37%), fever (34%), muscle pain (33%), fatigue (19%), joint pain (18%), nausea (8%), arthritis (5%), rash (4%), and sweating (3%).10 Data are not available to assess the safety of the vaccine during pregnancy; vaccinating pregnant women should probably be avoided unless the risk of exposure to EBOV is high.
Since the vaccine contains a live virus that causes stomatitis in animals, it is possible that the virus could be transmitted to humans and other animals through close contact. Accordingly, the CDC has published some precautions including, but not limited to, not donating blood and, for 6 weeks after vaccination, avoiding contact with those who are immunosuppressed.10 The vaccine is not commercially available in the United States and must be obtained from the CDC. Information on requesting the vaccine is available at www.cdc.gov/vhf/ebola/clinicians/vaccine/.