This year’s World AIDS Day is coming at a time of extremely mixed emotions — staggering disappointment, cautious optimism and a resolve to remain vigilant.
Some want to use the occasion to remind people at high risk to practice safe sex, noting a bump in the number of gay men infected with the disease. Others point out how India, China and some other nations — hoping to prevent new, massive explosions of the disease — are responding with aggressive public health and education campaigns. Still others are simply satisfied to note that existing drugs have transformed AIDS from a death sentence into a miserable chronic disease.
But the biggest challenge against the wily, rapidly evolving virus that causes AIDS is the fallout from a catastrophic setback in developing a vaccine — grumbling that perhaps it is time to give up the effort all together.
Two years ago, Merck, the National Institutes of Health and the HIV Vaccine Trials Network (HVTN) announced a novel public-private partnership to speed along Merck’s highly promising vaccine. The press release for the project burst with optimism: “The vaccine candidate used in this study has generated strong and durable cellular immune responses against HIV in early human trials. This collaboration could accelerate HIV vaccine development work by guiding scientific decisions for future HIV vaccine trials.”
That is why I don’t think I have ever seen a more grim, disappointed audience in a medical school than the day two weeks ago when a vaccine expert presented the data outlining what a dismal failure this latest best hope for a successful vaccine turned out to be.
The clinical trial involved 3,000 subjects in different cities around the world. But as the data trickled in, it became clear that not only was the vaccine failing to provide protection, it may have made people more likely to contract HIV.
The vaccine used a virus to transport three synthetic HIV genes meant to create an immune response. Instead, that virus may have allowed the HIV virus to hitch a ride and cause AIDS in some otherwise health people. As these grim results were reported, the sound of high hopes crashing to the floor echoed all around the lecture hall where I was sitting.
One of the gravest ethical violations that can occur in medical science is to engage in an experiment where someone who would not have otherwise been ill dies. That happened in the Merck vaccine trial. Exactly why is still a matter of debate but, the fact is, it did.
So the big question is: Should, as some are quietly suggesting in some circles, research on HIV vaccines be stopped?
No. That's just not an option.
The only way viral diseases such as polio and smallpox have ever been eradicated is through vaccination. Without a vaccine that can stop HIV in its tracks, the world faces more of the same — more people who lapse when it comes to risky behavior, more infections, more partially effective drugs, more money spent on those drugs, more sickness in the countries that can't afford the cost of drugs, more graves for those not already dead in the poorest nations.
Long road to a vaccine
It’s never been easy to develop vaccines to battle viruses.
Each year 3 million American kids are infected with rotavirus which can cause severe diarrhea, vomiting and fever. More than 70,000 wind up in the hospital. Dozens die. In poor nations, hundreds of thousands die every year.
There is now a vaccine against rotavirus. It took more than 20 years to produce it and was even recalled 10 years ago after a few children developed a rare and sometimes fatal condition after getting one of the early versions of the shot. Similar long and frustrating stories can be told about the polio vaccine, the vaccine against rabies and the new cervical cancer vaccine.
The HIV virus is a rugged opponent. It mutates quickly. It attacks the immune system itself, making it all the harder to find ways to create resistance to it. Finding a vaccine that works will take a sustained, unyielding effort. Part of that effort will involve deadly failures.
Our society is increasingly averse to risk. No one wants to be told that risk is an inevitable part of surgery or delivering a baby or, for that matter, flying in a plane or riding a horse. As we begin to gain some control over ancient plagues and scourges, we want a medicine that is risk free to create a risk-free world. It’s not going to happen. The world of viruses and bacteria make their living invading us, our pets, our crops and every other living thing on the planet. The battle against the nastiest versions, like HIV, is not for the faint of heart.
If we don’t want to be observing World AIDS Day for another 20 years, we had better be sure that the push to find a vaccine is not set back by the tragic failure of one trial upon which so much hope was placed.
Arthur Caplan, Ph.D., is director of the Center for Bioethics at the University of Pennsylvania.