Nipah and Hendra viruses (NiV and HeV) are closely related paramyxoviruses that can infect humans and various animal species, leading to severe disease and death. Currently, no therapy or prevention method exists to combat these pathogens, but now, a recent study in nonhuman primates offers some promise toward an effective vaccine (Sci. Transl. Med. 4, 146ra107).

Katharine N. Bossart et al. tested the effects of a recombinant subunit vaccine made from the attachment (G) envelope glycoprotein of HeV (sGHeV) in an African green monkey (AGM) model of lethal NiV infection. This vaccine has previously shown efficacy in small-animal models of HeV or NiV infection. They found that vaccination led to complete protection from NiV infection, with no evidence of disease, viral replication or pathology observed in the nine vaccinated AGMs.

Bossart et al. suggest that the spread of NiV in vivo is likely to be controlled by NiV-specific neutralizing antibodies elicited by the vaccine, as there was little evidence of a primary immune response after challenge, suggesting that there were low numbers of circulating virus.

Although efficacy trials of the sGHeV vaccine remain to be completed in primates challenged with HeV, the demonstration of protection from NiV in this study is an important step on the road to licensure of a vaccine to protect against these fatal viral infections.