Vaccine for Hantavirus Elicits Antibody Response

An experimental vaccine for hantavirus pulmonary syndrome (HPS) has elicited a strong neutralizing antibody response in monkeys. The results were reported in the September issue of the Journal of Virology.

The antibodies, produced in nonhuman primates that received the vaccine, protected hamsters from the lethal disease even when administered five days after exposure. Researchers say the vaccine may serve as a postexposure prophylactic treatment for HPS and a related disease, hemorrhagic fever with renal syndrome (HFRS). Currently, there are no vaccines or viral drugs to protect against either disease.

The research team constructed an expression plasmid containing the full-length M genome segment of Andes virus, a South American hantavirus. Vaccination with the plasmid elicited a potent neutralizing antibody response in rhesus macaques that were vaccinated a total of four times at three-week intervals. Serum samples were collected for about six months. The monkeys who received the Andes vaccine displayed robust antibody levels as long as 25 weeks after the last vaccination. The vaccine was developed by investigators at the US Army Medical Research Institute of Infectious Diseases (USAMRIID, Fort Detrick, MD, USA; www; www.usamriid.army.mil).

"Aside from the immunogenicity of the vaccine in nonhuman primates, the most exciting thing about this was the indication that postexposure prophylaxis might work, even five days out from exposure,” noted senior author Jay W. Hooper, Ph.D. "When we administered antibody after challenge, we got nearly complete protection.”