New experimental vaccines use viral DNA and proteins to help animals’ immune systems fight the virus that causes Middle East respiratory syndrome. The vaccines stimulate the production of antibody proteins that latch onto and disable the MERS virus, researchers report July 28 in Nature Communications.
When attacking MERS viruses, antibodies target a virus protein called the Spike glycoprotein. The scientists designed vaccines containing either the viral DNA with the genetic blueprint for making this protein, or a section of the protein itself. Two injections of DNA followed by one injection of protein, or two injections of protein, produced large amounts of virus-eliminating antibodies in mice and monkeys. Using both DNA and protein vaccines resulted in more diverse antibodies, the researchers say. Both vaccine combinations reduced lung damage in monkeys six days after MERS infection.
Though these particular vaccine regimens are not intended for the clinic, the results suggest that effective vaccines for MERS could be developed from the Spike protein, says study coauthor Barney Graham, a vaccinologist at the National Institute of Allergy and Infectious Diseases in Bethesda, Md.
No vaccine currently exists to combat MERS in humans. The virus has infected nearly 1400 people and killed about 500 worldwide since its identification in 2012.