Vaccinating Against Diseases, Without a Vaccine

On the heels of his being consulted about a novel study led by the Scripps Research Institute’s Michael Farzan, PhD, the work of The Children’s Hospital of Philadelphia’s Philip R. Johnson, MD, was highlighted in a new The New York Times article about immunoprophylaxis by gene transfer (IGT), a technology spearheaded in part by Dr. Johnson.

Last month, Dr. Farzan published a study in Nature that describes his team’s creation of a new molecule that prevents monkeys from being infected with simian/human immunodeficiency virus. That research builds on Dr. Johnson’s work with simian immunodeficiency virus (SIV) to develop proteins that act like antibodies called immunoadhesins. These proteins, which Dr. Johnson and his team delivered via recombinant adeno-associated virus (rAAV) vectors, successfully blocked SIV infection.

As The New York Times article notes, this approach “is altogether different from traditional vaccination.” Instead, it is more akin to gene therapy, for in the case of HIV the AAV-delivered antibodies “can latch onto many different strains of the virus and keep them from infecting new cells.”

“The new study reinforces the potential promise of the AAV-mediated immunoprophylaxis approach as an alternative to vaccination to prevent HIV infection,” said Wayne C. Koff, chief scientific officer of the International AIDS Vaccine Initiative (IAVI), after Dr. Farzan’s study was published. “We look forward to further studies that will show how well any of these approaches can work in humans and will bring us all closer to a world without HIV/AIDS.”

Following that, Children’s Hospital last year partnered with IAVI to launch a clinical trial to study the safety of the rAAV vector carrying the broadly neutralizing antibody PG9, which has been shown to protect against HIV. The study team hopes to collect data later this year.

“For Dr. Johnson,” the Times article notes, “the growing interest in IGT is gratifying. ‘It’s catching on, but it’s certainly not mainstream,’ he said. That seems likely to change, and soon.” “The sky’s the limit,” said Dr. Farzan.

Read the whole thing at The New York Times.