3-D reconstruction of Zika virusWIKIMEDIA, THOMAS SPLETTSTOESSERIn the last year, a diverse suite of anti-Zika vaccines has rapidly advanced through preclinical development and into human trials. A Phase 1 trial testing one approach, which relies on DNA to encode vaccine components, has already yielded encouraging results. Now, another nucleic acid, messenger RNA (mRNA) is joining the Zika-vaccine toolbox. According to a study published in Nature today (February 2), a single shot of a vaccine containing Zika virus mRNA encapsulated in a lipid nanoparticle induced protective immune responses in both mice and Rhesus macaques.
“It’s a novel vaccine platform. It has not been explored in great detail in humans yet, but it will have more clinical experience going forward,” said Dan Barouch, who directs the Center for Virology and Vaccine Research at Harvard Medical School and was not involved in the present study.
Like the current DNA vaccines, the mRNA-based vaccine encodes the Zika virus pre-membrane protein and the envelope protein. Once produced by a vaccine recipient’s cells, the proteins elicit an antiviral immune response. The difference, explained study coauthor Drew Weissman, an immunologist at the University of Pennsylvania, is that mRNA can bypass many of the obstacles that stand between DNA and protein production, such as transport to the nucleus and transcription into RNA. “With RNA, it just ...
