Two doses of an investigational DNA vaccine protected 17 of 18 rhesus macaques from infection with the Zika virus in a recent study published in Science. In 6 monkeys that received a single injection at a low dose, subprotective levels of neutralizing antibodies were detected that resulted in breakthrough infections.
The vaccine used in the study, which was led by a team at the National Institute of Allergy and Infectious Diseases, encodes the structural proteins premembrane (prM) and envelope (E). These components are sufficient for the release of virus-like subviral particles that are similar to infectious virions. Sequences for prM and E particles were inserted into an expression vector along with additional sequences to improve expression and subviral particle secretion.
Hampton T. DNA Vaccine Protects Monkeys Against Zika Virus Infection. JAMA. 2016;316(17):1755. doi:10.1001/jama.2016.15862