Thailand Vaccine the Beginning of the End of AIDS?

Bangkok, Thailand – I have vivid memories of treating patients infected with human immunodeficiency virus (HIV) in the nascency of the pandemic in the 1990s. Mostly I recall telling patients they were going to die in a matter of months if they didn’t go on the incredibly difficult drug cocktail doctors were prescribing at that time – it was all we had. Sadly, some opted for unfettered death.

Since then I’ve followed developments in HIV medicine peripherally, as it has burgeoned into an incredibly complex medical subspecialty. We’ve seen treatment options go from one drug with crippling side effects to more than 2 dozen drugs with manageable side effects. Although there are about 33 million infected worldwide, with many more thousands infected every day, doctors are no longer telling newly-diagnosed patients to get their papers in order. And despite its reputation as a disease of gay men, more than half of those infected with HIV are women.

So it was an incredible honor to be invited by the National Press Foundation into fellowship to attend the AIDS Vaccine Conference in Bangkok, Thailand, this month. The conference, sponsored by the Global HIV Vaccine Enterprise, the Thai Ministry of Health and Mahidol University, was being held in Asia for the first time.

Why Thailand? As it turns out, the first promising HIV vaccine trial results came from a study performed here. In 2009, the groundbreaking RV144 clinical trial made worldwide headlines by boasting of a protection rate of 31% in 8000 vaccinated volunteers. These surprising results energized HIV vaccine researches that had been browbeaten by decades of setbacks in previous experiments. A vaccine that is only 31% effective is not effective enough to be manufactured and used on patients, but the trial demonstrated that a vaccine for HIV is possible, the elusive “proof of concept.”

Why is a vaccine so important? First of all, it’s the only possibility of wiping out this immune-system-destroying virus. A vaccine is our only hope to rid the earth of AIDS, as it did for smallpox, and as it is on its way for doing for polio. Second, the world can’t bear the enormous financial burden of caring for and treating those infected with HIV. One scientist estimated the cost of treating all persons infected with HIV at $30 billion in a 10-year span, with annual costs of treatment at a modest $8,000 – $12,000, not to mention social, family and lifestyle disruption. A vaccine would cost only $800 a pop. During the opening ceremony, Dr. Carl Dieffenbach, of the National Institutes of Health, summed it all up. “The Holy Grail of HIV prevention remains a safe, efficacious and durable HIV vaccine.”

Why is a vaccine so elusive? It’s a huge scientific challenge – the HIV virus has thousands and thousands of strains and changes its composition frequently to escape annihilation. It operates under the presumption that the best defensive is a good offensive, and holds a person’s immune system hostage by wiping out the body’s own immune cells that are needed to fight it.

Many vaccine attempts have been made under the Fail Fast Principle: screen out as quickly as possible vaccines and vaccine mechanisms of action that aren’t going to work, so that the most time and the real money can be spent on hypotheses that have a real chance. The title of this conference is a misnomer. In my opinion, it should be called the HIV Vaccine Conference. Because everyone who has AIDS is infected with HIV, but not everyone who is infected with HIV has AIDS. AIDS is a medical term for those most severely impacted by the infection, whether it’s because they’ve developed a complicating illness, like pneumonia, or because their immune system is failing, as demonstrated by laboratory testing. And we are in pursuit of a vaccine that will prevent or halt the infectious process, not just the most severe implications of the infection.

So here we are. In 2011, on the 30th anniversary of the first HIV cases in the U.S., we can finally see a light at the end of the tunnel. Decades of research on an HIV vaccine has finally been vindicated. Although years away, thousands of vaccine trial participants shy of drug approval, many millions of dollars in need, and with discoveries of other prevention techniques and exciting giant steps along the way — issues that I will explore throughout this conversation – the tightly knit and committed HIV scientists have circled the wagons and are taking their best collaborative shots towards the eradication of the human immunodeficiency virus.

By Dr. Mona Khanna