HIV vaccine still far from effective
By Emily Tice
Sept. 29, 2009 11:06 p.m.
Effective treatments and vaccines for HIV have so far been elusive, and UCLA researchers said they do not believe a solution for either will present itself in the next few years.
A recent study in Thailand found an HIV vaccine that is 31 percent effective in reducing HIV infection, according to a statement from the National Institutes of Health.
However, Kathie Ferbas, an assistant professor in the David Geffen School of Medicine who also conducts HIV research, said it is still too early to come to conclusions about the newest HIV vaccine, which is actually a combination of two vaccines previously determined to be ineffective.
She also expressed doubt that an effective HIV vaccine will be developed in the near future, as vaccines must typically be 70 to 80 percent effective before being approved for use.
While the announcement on Thursday regarding the new vaccine has generated a lot of attention, the National Institute of Allergy and Infectious Diseases said the full analysis will not be published for another month.
Ferbas said that many people in less developed countries cannot afford the medications and that a vaccine would be a far more cost-effective option, even if it were to cost several hundred dollars.
Ferbas added that more research on HIV was necessary to better understand the nuances of the disease.
“Historically, vaccines have always been made empirically. You look at a disease, you make a vaccine, and it’s always worked. For those where that approach doesn’t, and with HIV we tried, we have to understand it better.”
She said controlling the spread of HIV is almost certainly impossible without a vaccine.
“There’s never been a viral pandemic that’s been controlled by anything other than vaccination,” Ferbas said.
But while vaccines are a preventative measure, millions are already infected and still require treatment.
Ronald Mitsuyasu, a professor in the David Geffen School of Medicine, has been leading research to find better HIV treatments through gene therapy, which involves inserting genetic material into cells to alter how they function.
His research, released in March, was conducted on 74 HIV-positive adults and was the first study to determine whether or not gene therapy had an effect on viral load.
He found that there was an irreverently small difference between the group that had been given gene therapy and the group that had not, but he did not believe that this diminished the promise of gene therapy as an effective treatment against HIV.
“Things don’t happen overnight. You don’t go from nothing to having a cure,” he said.
Mitsuyasu said that one of the benefits of developing a viable form of gene therapy is that it has virtually no short-term side effects, which is important because current HIV medications can be severe. Even if researchers found better ways to insert the genes into cells or create more potent genes, he said he believes it is unlikely that this would increase the number of side effects.
Another benefit of gene therapy is that it would be administered less frequently. While current medications are very effective at reducing the HIV virus to virtually undetectable levels in 80 to 90 percent of patients, they must be taken daily, and failure to do so results in resistance to the medication, Mitsuyasu said.
However, while current medications cost roughly ten thousand dollars a year, gene therapy would still be expensive because it has to be specialized to each patient. And modifying the genetic material in the cell raises ethnical concerns, so even if research were to be completed, legal issues would soon follow.
Mitsuyasu said he does not envision gene therapy to be a viable treatment within the next five years, but called his study incremental improvement.
“The study was more proof of concept. But the same thing can be said of the vaccine trial in Thailand ““ the result was modest, but there was a clear signal.”
But Mitsuyasu warned that there may never be a cure.
“That “˜e’ word, the eradication word, is one we don’t use very much when talking about treatment, because we know HIV is a hard disease,” he said.
