Recombinant Vesicular Stomatitis Virus Vaccine Vectors Expressing Filovirus Glycoproteins Lack Neurovirulence in Nonhuman Primates

Ebola and Marburg viruses are some of the filoviruses that cause fatal haemorrhagic fever in both humans and nonhuman primates. Vesicular stomatitis virus (VSV) from the family Rhabdoviridae has a simple genome structure and foreign genes can be inserted in the genome. This ability has been explored in the development of vaccines against other viral diseases. Recombinant VSV is also able to increase the virus titres in mammalian cells but cannot insert or recombine into the host cell genome. These factors make it a good candidate for recombinant vaccine development. To prevent diseases caused by these filoviruses advanced developments with promising results regarding vaccines production have been made. Recombinant vesicular stomatitis virus (rVSV) with filovirus glycoprotein expression instead of VSV glycoprotein (GP) has been used. There has been concerns about the safety of these competent replication vaccines and therefore this study performed a neurovirulence experiment using cynomolgus macaques. These animals were divided into groups and given rVSV vectors expressing different GPs from different filoviruses. One group got rVSV vector with Zaire Ebola GP, another with Lake Victoria Marburg virus GP, another received rVSV wild type and the last group was the control. The results showed that there were no symptoms and neural lesions on all animals that received rVSV filovirus vaccines. Symptoms and lesions were observed in animals that received the wild type rVSV. This indicates that rVSV expressing filovirus glycoproteins vaccines do not have neurovirulence properties.

(BEC)