Cell Host and Microbe Interpretation! Experimental vaccines may be effective in preventing SARS-CoV-2 infections!

August 19, 2020 // -- A recent study published in the international journal Cell Host and Microbe entitled "Replication-competent vesicular stomatitis virus vaccine vector protects against SARS-CoV-2-mediated pathogenesis in mice" In the report, scientists from the University of Washington School of Medicine and others said an experimental vaccine could effectively prevent pneumonia in mice infected with the SARS-CoV-2 virus, which is made from a mild virus genetically modified to carry key genes from the SARS-CoV-2 virus.
researcher Michael S. Diamond says that unlike other vaccines being developed, the new vaccine is made from a virus that can spread only in the body, which means it appears to induce a strong immune response from the body, which is only available in the laboratory because of its ability to replicate. Higher levels of reproduction and growth make it easy to scale up and be more effective than some other vaccine candidates, and although the researchers are showing only proof of concept, this study seems to be very much a game-changer, with the vaccine currently being tested in other animal model bodies and entering clinical trials later or soon.
Photo Source: National Institute of Allergy and Infection Diseases, NIH researchers created the experimental vaccine by genetic modification of the blistered oral inflammatory virus (VSV, vesicular stomatitis virus), which causes mild transient diseases in livestock, and replaced a gene in VSV with a sting gene called SARS-CoV-2, also known as VSV-SARS-CoV-2.
prickly protein is one of the keys to the body's immunity against COVID-19, SARS-CoV-2 can use hedgehog protein to tether and infect human cells, while the human body also produces protective antibodies to targeted viral hedgehog proteins To fight viral infections, and by adding the prickly protein gene to a harmless virus, the researchers were able to create a hybrid virus that, when given to people, would ideally produce antibodies against the prickly protein, effectively preventing COVID-19 infection.
researchers also used the same strategy to design the Ebola virus vaccine, which was approved by the FDA in 2019 and is made by genetically modifying VSV to carry genes from the Ebola virus, which has now been safely vaccinated by thousands of people in Africa, Europe and North America and helped end the Ebola epidemic in the Republic of Congo in 2018-2020.
As part of the study, the researchers compared laboratory strains of VSV-SARS-CoV-2 or VSV injected into mice, and four weeks after the initial injection, the researchers injected the mice with a second experimental dose of the vaccine, and three weeks after each injection, the researchers took a sample from the mice. Blood draw in the body to detect the ability to produce antibodies against SARS-CoV-2 infection, it was found that after the first experimental vaccine injection, mice can produce higher levels of neutral antibodies, and after the second injection, the level of protective antibodies increased 90 times.
Five weeks after the last dose of the vaccine, researchers sprayed the nasal cavity of mice with SARS-CoV-2 to test whether the mice were effective against infection with the virus, and the results showed that the new experimental vaccine helped mice effectively resist coVID-19. Four days after infection, the lungs of mice vaccinated with one or two doses did not detect an infectious virus, but instead, mice with a placebo developed high levels of the virus in their lungs, and the vaccinated mice showed fewer signs of inflammation and damage to their lungs than mice that received a placebo.
researchers say the new vaccine is still in its early stages of development and does not naturally infect mice with SARS-CoV-2, so to assess whether the experimental vaccine produces a protective immune response in mice, researchers studied genetically modified mice or undefitoued mice and used Complex techniques to induce its sensitivity to viral infections are currently being repeated by researchers in other animals susceptible to SARS-CoV-2 infection, and the next step is to scale up production under conditions the FDA considers high-quality production scale (GMP) and conduct clinical trials in humans.
Despite the promising current research data, the development of the vaccine has been expanding for months in the race to end the epidemic, and six vaccines are now in the final stages of testing in the population, and researchers at the National Institute of Allergy and Infectious Diseases in the United States say they expect the COVID-19 vaccine to be large-scale early next year. Finally, researcher Whyan said, it may really depend on the success of the first vaccines, coVID-19, if it does not produce a strong and long-lasting immune response, or if there are some safety problems, then researchers are likely to launch a second-generation vaccine, and will induce inactivated immunity and interrupt the transmission cycle of the virus.
() Original source: 1: 1: 1. Covid-19 vaccine prevents severe disease in mice (2) James Brett Case, Paul W. Rothlauf, Rita E. Chen, et al. Replication-competent vesicular stomatitis virus vaccine vector protects against SARS-CoV-2-mediated pathogenesis in mice, Cell Host and Microbe (2020). doi:10.1016/j.chom.2020.07.018.