THE RACE FOR A ZIKA VACCINE
Despite these difficulties, Barouch saw the promise of the naked-DNA technique. If it could be perfected, dozens of vaccine candidates for dozens of pathogens could be tested without having to grow buckets of those pathogens in labs. The scale-up issues would still need solving, but the painstaking, often artisanal process of growing viruses in tissue culture or in eggs—the tedium of isolation and decontamination, gowns, masks, face shields, doubled-up gloves—would be vastly diminished. If the naked-DNA vaccine works against Zika—“the big if,” as Barouch puts it—it will have a transformative impact not just on this epidemic but on vaccine technologies in general.
“It would be a game-changer for vaccinology,” Colonel Stephen Thomas, an infectious-diseases physician and a vaccinologist at the Walter Reed Army Institute of Research (wrair), in Silver Spring, Maryland, said. “Perhaps the effort to create a Zika vaccine is where the DNA vaccine will demonstrate its potential.” At least one trial involving a DNA-based vaccine for H.I.V.—a far more difficult target—failed to show a benefit. And although a DNA vaccine for West Nile virus has been used successfully in horses, no DNA vaccine has so far been licensed for human use. “DNA vaccines may be the vaccines of the future,” Barouch said, “but they haven’t had much of a track record in clinical medicine so far.” Given the uncertainties, he wanted to compare both old-school and new-school vaccines, head-to-head, using the mouse model for Zika infection. – READ MORE