Vaccination 7 days before infection can protect macaques from Ebola virus

  In the fight against the recent Ebola outbreak, some good news emerged: a preclinical test to test the efficacy of the VSV-EBOV (previously called rVSV/ZEBOV-GP) vaccine in non-human primates Studies have shown that when vaccinated 7 days before infection, the vaccine has full protection, and vaccinated 3 days before infection has partial protection. The positive results of this research revealed an effective way to make an immune response to the Ebola virus, which has a profound impact on minimizing the Ebola outbreak.

  In a study conducted by Andrea Marzi and others, they vaccinated a group of rhesus monkeys with VSV-EBOV 28 days, 21 days, 14 days, 7 days and 3 days before being infected with Ebola virus; The Makona strain of Ebola virus. There were no detectable adverse reactions after vaccination, and these macaques were tested for 42 days after being infected with a lethal dose of Ebola virus. The animals in the control group were vaccinated with a vaccine that was known to be ineffective, and they had to be euthanized because of severe Ebola symptoms.

  One of the rhesus monkeys in the group of rhesus monkeys vaccinated with the VSV-EBOV vaccine 3 days before infection did not survive, while the other 2 rhesus monkeys in the group showed only mild and moderate symptoms of Ebola infection, but eventually cleared Ebola virus in its body. All the remaining 9 rhesus monkeys vaccinated 28 days, 21 days, 14 days and 7 days before infection did not show any clinical signs of disease. In previous studies, the presence of immunoglobulin G antibodies against Ebola virus is related to the survival of animals; when infected with the virus, these rhesus monkeys who were vaccinated 28 days, 21 days and 14 days before infection showed high levels. Concentration of Ebola virus-specific antibodies. Exhausted

  Although at the time of infection, the rhesus monkeys that were vaccinated 3 and 7 days before infection did not have Ebola virus-specific antibodies, but the rhesus monkeys in the vaccinated group 3 days before infection appeared on the 6th day after Ebola virus infection. Detectable Ebola virus-specific IgG antibodies. Therefore, the researchers said that the VSV-EBOV vaccine can stimulate a powerful innate immune response, which can help limit virus replication during the critical period when the body produces Ebola-specific antibodies.