Protection Without a Vaccine

Carl Zimmer in The New York Times:

VaccineLast month, a team of scientists announced what could prove to be an enormous step forward in the fight against H.I.V. Scientists at Scripps Research Institute said they had developed an artificial antibody that, once in the blood, grabbed hold of the virus and inactivated it. The molecule can eliminate H.I.V. from infected monkeys and protect them from future infections. But this treatment is not a vaccine, not in any ordinary sense. By delivering synthetic genes into the muscles of the monkeys, the scientists are essentially re-engineering the animals to resist disease. Researchers are testing this novel approach not just against H.I.V., but also Ebola, malaria, influenza and hepatitis. “The sky’s the limit,” said Michael Farzan, an immunologist at Scripps and lead author of the new study. Dr. Farzan and other scientists are increasingly hopeful that this technique may be able to provide long-term protection against diseases for which vaccines have failed. The first human trial based on this strategy — called immunoprophylaxis by gene transfer, or I.G.T. — is underway, and several new ones are planned.

…I.G.T. is altogether different from traditional vaccination. It is instead a form of gene therapy. Scientists isolate the genes that produce powerful antibodies against certain diseases and then synthesize artificial versions. The genes are placed into viruses and injected into human tissue, usually muscle. The viruses invade human cells with their DNA payloads, and the synthetic gene is incorporated into the recipient’s own DNA. If all goes well, the new genes instruct the cells to begin manufacturing powerful antibodies. The idea for I.G.T. emerged during the fight against H.I.V. In a few people, it turned out, some antibodies against H.I.V. turn out to be extremely potent. So-called broadly neutralizing antibodies can latch onto many different strains of the virus and keep them from infecting new cells.

More here.