Novel HIV Vaccine Gaining Momentum

The backers of an experimental HIV vaccine say they’re preparing to launch a major phase 2b study in Africa, in the coming months.

The National Institutes of Health (NIH), Janssen Pharmaceuticals and the Bill & Melinda Gates Foundation announced plans last month to enroll 2,600 HIV-negative women in a study to test the safety and efficacy of a new “mosaic-based” vaccine.

The vaccine was developed in the laboratory of Dan Barouch, MD, PhD, of Harvard Medical School and Beth Israel Deaconess Medical Center. He worked alongside Janssen and other partners.

Barouch told MD Magazine the push for an HIV vaccine has been gaining momentum.

“We developed a consortium to advance this vaccine over the past several years,” he said. “We are very pleased that multiple funders, stakeholders, and collaborators have been very enthusiastic to work together to move this vaccine forward.”

The study is named “Imbokodo” — the Zulu word for “rock" — and is a reference to an African proverb that refers to the strength of women.

The vaccine regimen is based on mosaic immunogens, which are designed to create a buffer against various strains of HIV. The diversity of HIV strains has been 1 major hurdle in creating a vaccine for the disease. The regimen has already proven effective at stopping the transmission of an HIV-like virus in monkeys.

Anthony S. Fauci, MD, the director of NIH’s National Institute of Allergy and Infectious Diseases, said such a vaccine, if successful, could finally draw the HIV/AIDS epidemic to a close.

“Together with the implementation of existing HIV prevention and treatment strategies, the development and delivery of a preventive HIV vaccine that is safe and at least moderately effective would help bring about a durable end to the HIV/AIDS pandemic,” said Fauci, in a press release.

The new study comes on the heels of a related trial, the HVTN702 trial, a phase 2b/3 study launched last year in South Africa. The vaccine regimen in that study uses an updated version of the RV144 Thai trial’s regimen. According to the NIH, RV144 Thai is the only vaccine regimen thus far that has proven to be at least partially effective at stopping transmission of the virus.

The new Imbokodo study will be launched in South Africa, though officials hope to expand the footprint of the study into 4 other African countries. Participants will be given either a vaccine or placebo 4 times per year. The final 2 doses will include an HIV protein and an aluminum phosphate adjuvant in an effort to boost immune responses.

Forty-three percent of the 1.8 million new HIV infections in 2016 occurred in South and Eastern Africa. Women and girls face the highest risk of infection.

Though anticipation for a vaccine is high, it will still be a number of years before there will be enough data to determine if the Imbokodo study vaccine should be deployed on a wide scale.

“The HVTN705 (Imbokodo) study is estimated to take approximately 2 years to enroll, and then there will be approximately 2 years of follow-up time before we know whether or not the vaccine worked,” Barouch said. “In the interim, the HVTN702 HIV vaccine study might have data to share.”

More information on the trial can be found at this link.

This article was originally published by MD Magazine.