Sunday, May 29, 2011

AIDS Researchers Eye Flurry of Promising Vaccine Developments

A version of this article originally appeared in the Black AIDS Institute’s Black AIDS Weekly email. Colorlines joins other black community media in co-publishing content from the Black AIDS Weekly.

The past three weeks have seen a flurry of activity around the potential of developing and using a vaccine for HIV, which has spawned an epidemic that will turn 30 years old next month and has ravaged poor countries around the world and black neighborhoods in the U.S.


In Kenya, clinical trials began on two promising new designs for preventive HIV vaccines. In South Africa, researchers launched clinical trials on a therapeutic vaccine intended to strengthen the immune systems of people living with HIV/AIDS. And just last week, scientists at the University of Maryland School of Medicine announced their biggest research gift ever: $23.4 million to continue the university’s decades-long work on an HIV/AIDS vaccine from a consortium led by the Bill & Melinda Gates Foundation.

“I don’t think anyone can argue that this hasn’t been an exciting time,” says Mitchell Warren, executive director of AVAC, originally the AIDS Vaccine Advocacy Coalition.

Prevention technologies have been in the news lately—from the breakthrough microbicide research at the 2010 International AIDS Conference to the recent data on the potential of pre-exposure prophylaxis (PrEP) to help protect gay and bisexual men. And all have potentially serious implications for African Americans, who represent less than 13 percent of the U.S. population but account for 45 percent of new HIV infections.

Preventive Vaccine Trials

“There are three major areas of work right now around vaccines,” Warren explains. “On the one hand, there is a lot of work focused on doing better than what we did in Thailand, how to modify that vaccine candidate and improve upon it.”

Announced in September 2009, the U.S.-funded “Thai Prime-Boost” trial—the world’s largest vaccine trial, with 16,000 volunteers—combined two previously unsuccessful vaccines. It marked a medical milestone (the vaccine reduced new infections by almost a third), but it was not effective enough to move to market.

“The second major area of work is [coming up with] other new vaccine concepts. The trial in Kenya is one example,” says Warren of the research being conducted in collaboration with the International AIDS Vaccine Initiative (IAVI). The Kenya trial has been described as “the most advanced AIDS vaccine design” that is likely to succeed.

Another major effort is in the early stages at the University of Maryland’s Institute of Human Virology, headed by the renowned Robert C. Gallo, M.D., who helped discover HIV and later developed the HIV blood test. Researchers there are exploring a novel HIV-vaccine candidate that would neutralize “many different strains of HIV.” Previous vaccine candidates responded only to a single type of the disease.

“With the possibility of an HIV vaccine that could prevent many different strains of this disease, we could indeed be changing the world,” says E. Albert Reece, dean of the University of Maryland School of Medicine. Reece, who is African American, describes the new vaccine candidate’s potential as “extraordinary.”

The third major focus of research “has gotten a lot of people excited,” says AVAC’s Warren: The discovery of new details about how the virus itself. “Scientists broke the code and [can] find additional areas of the HIV virus that might be better targets,” for a neutralizing vaccine.

One recent example: Scientists in Oregon announced an experimental vaccine that helped monkeys control their infections for more than a year. This is the first time that a vaccine candidate has been able to “fully control the virus in some animals,” Wayne C. Koff, chief scientific officer at the IAVI, told Reuters.

Some Progress on Therapeutic Vaccines

Positive developments have also occurred on therapeutic vaccines, intended to one day boost the ravaged immune systems of people living with HIV/AIDS.

Clinical trials on a vaccine candidate called TAT were announced at the University of Limpopo in South Africa. Participants continue to take their antiretroviral medications (ARVs) as researchers investigate “what health restorative qualities the candidate vaccine has that ARVs do not possess,” reports The Sowetan.

This approach appears particularly promising for African and Caribbean nations, where many patients do not have easy access to lifesaving treatment medication. An estimated 5.7 million HIV-positive people live in South Africa alone—more than in any other nation.

Meanwhile, efforts continue to get more people of color enrolled in vaccine trials. Blacks and Latinos are generally underrepresented in clinical research, a fact that concerns advocates and researchers who point out that whatever gets developed must work for the lives and bodies of people who most need it. There has been a nationwide, sustained effort by the NIH-funded HIV Vaccine Trials Network’s Legacy Project to recruit more black and Latino participants.

“In the United States, African Americans are at greatest risk for HIV. Not to acknowledge that, or not to design our research around that, means we are reinforcing the very obstacles that the virus preys upon,” AVAC’s Warren reminds us. “Whether it be for a vaccine, for a therapy, microbicide or PrEP, we need to make sure that diverse populations are enrolling in the clinical trials.

“But we will find a vaccine,” Warren adds. “There is no doubt, given all the recent advances.”

Rod McCullom, a writer and television news producer, blogs on Black gay, lesbian, bisexual and transgender news and pop culture at rod20.com.

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