Rift Valley fever virus (RVFV), a recognized category A priority disease, produces significant epidemics of Rift Valley fever in people, with occasional fatalities and massive economic losses in animals. Researchers created a high-titer vesicular stomatitis virus (VSV) pseudotype containing RVFV envelope glycoproteins to detect neutralizing antibodies in vitro under BSL-2 conditions because wild-type RVFV must be handled in BSL-3 or BSL-4 facilities. The neutralizing capabilities of 39 amino acid mutant sites that have evolved spontaneously throughout time in the RVFV envelope glycoproteins were investigated individually with their matching pseudo viral mutants. There were no statistically significant differences between the variations and the main strain findings. Following that, they created a Balb/c mouse pseudovirus infection paradigm in order to identify neutralizing antibodies against pseudovirus. The mice were protected from infection with the pseudovirus after five vaccinations with pseudo viral DNA. They found a strong connection between neutralizing antibody titers in vitro and bioluminescence imaging, which we utilized to analyze viral spread and distribution in mice.

With the long-term goal of preventing Rift Valley disease, these pseudovirus techniques will enable the safe determination of neutralizing antibodies both in vivo and in vitro.

Reference: https://www.tandfonline.com/doi/full/10.1080/21645515.2019.1627820