National Institutes of Health (NIH) scientists report that a single dose of an experimental Ebola virus (EBOV) vaccine completely protects cynomolgus macaques against the current EBOV outbreak strain, EBOV-Makona, when given at least seven days before exposure, and partially protects them if given three days prior. The live-attenuated vaccine, VSV-EBOV, uses genetically engineered vesicular stomatitis virus (VSV) to carry an EBOV gene that has safely induced protective immunity in macaques. The experimental vaccine is currently undergoing testing in a global clinical trial in humans. VSV, an animal virus that primarily affects cattle, has been successfully tested as an experimental vaccine platform against several viruses.
First author Andrea Marzi, PhD, of NIAID's Laboratory of Virology, is shown in August 2014 analyzing Ebola test results from the ELWA3 hospital compound in Monrovia, Liberia. Photo courtesy of NIAID
National Institutes of Health (NIH) scientists report that a single dose of an experimental Ebola virus (EBOV) vaccine completely protects cynomolgus macaques against the current EBOV outbreak strain, EBOV-Makona, when given at least seven days before exposure, and partially protects them if given three days prior. The live-attenuated vaccine, VSV-EBOV, uses genetically engineered vesicular stomatitis virus (VSV) to carry an EBOV gene that has safely induced protective immunity in macaques. The experimental vaccine is currently undergoing testing in a global clinical trial in humans. VSV, an animal virus that primarily affects cattle, has been successfully tested as an experimental vaccine platform against several viruses.
Prior to this study, scientists had no information about how monkeys vaccinated with VSV-EBOV would respond to a challenge with EBOV-Makona, which has spread throughout West Africa. Previous animal studies demonstrated that VSV-EBOV could successfully protect monkeys against the first EBOV strain recognized, Mayinga, in 1976, and against EBOV-Kikwit, a strain that emerged in Central Africa in 1995. This new study shows that certain immune responses induced by VSV-EBOV are similar against all three viruses. The scientists, from NIH's National Institute of Allergy and Infectious Diseases Division of Intramural Research, concluded from these findings that VSV-EBOV likely would be equally protective against different EBOV strains.
The group also observed that the experimental VSV-EBOV vaccine appears to provide initial protection by triggering innate virus-fighting host responses; these responses partially protected animals challenged with EBOV-Makona within a week after vaccination. Animals vaccinated more than a week before viral challenge developed antibodies, an adaptive immune response, that were shown to be critical for protection.
Reference: Marzi A, et al . VSV-EBOV rapidly protects macaques against infection with the 2014/15 Ebola virus outbreak strain. Science DOI: 10.1126/science.aab3920 (2015).
NIH/National Institute of Allergy and Infectious Diseases
How Contaminated Is Your Stretcher? The Hidden Risks on Hospital Wheels
July 3rd 2025Despite routine disinfection, hospital surfaces, such as stretchers, remain reservoirs for harmful microbes, according to several recent studies. From high-touch areas to damaged mattresses and the effectiveness of antimicrobial coatings, researchers continue to uncover persistent risks in environmental hygiene, highlighting the critical need for innovative, continuous disinfection strategies in health care settings.
Beyond the Surface: Rethinking Environmental Hygiene Validation at Exchange25
June 30th 2025Environmental hygiene is about more than just shiny surfaces. At Exchange25, infection prevention experts urged the field to look deeper, rethink blame, and validate cleaning efforts across the entire care environment, not just EVS tasks.
A Controversial Reboot: New Vaccine Panel Faces Scrutiny, Support, and Sharp Divides
June 26th 2025As the newly appointed Advisory Committee on Immunization Practices (ACIP) met for the first time under sweeping changes by HHS Secretary Robert F. Kennedy Jr, the national spotlight turned to the panel’s legitimacy, vaccine guidance, and whether science or ideology would steer public health policy in a polarized era.