A two-step vaccination process to protect against the Middle East respiratory syndrome coronavirus (MERS-CoV) was recently successfully administered to mice and rhesus macaque.
MERS-CoV was first reported in Saudi Arabia in 2012 and has since spread to several other countries. The virus causes flu-like symptoms which can develop into a severe respiratory illness that can be fatal. According to the World Health Organization (WHO) it has already killed at least 487 people, while 1368 laboratory-confirmed cases have been reported.
The virus most likely transmits to a human from an animal source. Virus detection in camel milk and lymph node samples suggests that camels may be the source of human infection. Person to person transmission probably occurs by respiratory secretions through coughing, however the exact method of virus transmission is so far not well understood. There is no special treatment for the disease and as yet no known vaccine.
Past attempts to develop coronavirus vaccines were mainly based on the use of whole inactivated viruses, live-attenuated viruses, recombinant protein subunits or genetic approaches. In a recent study, researchers from the National Institute of Allergy and Infectious Diseases’ Vaccine Research Center used structural information about a membrane-anchored Spike (S) glycoprotein, which mediates virus entry into cells, to design a number of experimental vaccines.
They first vaccinated mice with an initial injection which was followed several weeks later by the same or a different vaccine. From eight vaccine regimens tested on mice, the three that provoked the most robust immune response were taken for evaluation in rhesus macaques, where they produced similar immune system responses. Immunization also protected rhesus macaques from severe lung disease after an intratracheal challenge with MERS-CoV.
The results of this study indicate that an understanding of the viral structure and interactions of the virus with host cells is an important step in the development of an effective vaccine. New findings may help in the development of a human MERS vaccine.
Read the original scientific article: Evaluation of candidate vaccine approaches for MERS-CoV
By Katarina Kovac, PhD, Product Manager, BioSistemika LLC