By Mark Mulligan, MD
Since the mid-1990s, thousands of patients with HIV/AIDS have been successfully treated with combinations of drugs known as “highly active antiretroviral therapy.” In many cases, these drugs have turned a disease that used to be a sure death sentence into a treatable, chronic condition.
Unfortunately, in spite of widespread efforts to prevent HIV, 33 million people around the world are infected, and in the U.S. alone the CDC estimates that about 56,000 persons are newly infected with HIV each year. Since therapy does not cure HIV, every new infection means a person must be treated for life with costly medications.
For this reason, the world desperately needs an HIV vaccine. Historically, vaccines have been our most effective weapons against infectious diseases. Unfortunately, over the past five years, two large clinical trials of HIV vaccines have failed to demonstrate efficacy of the candidate being tested, leaving many to wonder if we should simply give up on an HIV vaccine altogether.
AIDS is too widespread and too devastating a disease to abandon the quest for a vaccine. Scientists have learned many important lessons from past vaccine trials, and there is no reason to give up now.
We should remember that our most important vaccines took decades to develop. The virus that causes polio was discovered in the 1930s. The first vaccines tested in the 1930s were ineffective. In the 1940s and early 1950s, summertime polio epidemics caused fear and panic in many countries. Fortunately, this vaccine research continued despite initial failures.
Progress was based on small but steady scientific advances such as the discovery in 1949 of how to grow the polio virus in the lab. Six years later, Jonas Salk’s inactivated, injected polio vaccine became available. By 1957 the number of new polio cases annually had fallen by 90 percent and the iron lung became a museum relic.
Scientists at the Emory Vaccine Center and the Yerkes National Primate Research Center have been working on an HIV/AIDS vaccine for a decade. Based on DNA and viral vector technology, the vaccine is licensed to the Atlanta biotechnology company GeoVax to bring it to the marketplace.
The vaccine has made it through several early stages of clinical trials and is now being tested in a Phase II clinical trial to understand its effectiveness through the National Institutes of Health-funded HIV Vaccine Trials Network (HVTN). In Atlanta, Emory Vaccine Center’s Hope Clinic is the HVTN clinical site. There are other HIV vaccines also being tested. Another Phase II is undergoing a clinical trial through the HVTN network to test a different HIV vaccine, this one developed at the National Institutes of Health.
As a doctor working with individuals who have HIV or AIDS, I know the toll this disease takes on them and their loved ones. I am very hopeful that an effective HIV vaccine will be developed, and I am proud to be on the front lines of that effort.
Both of the new HIV vaccine clinical trials are aimed at healthy adults at low risk for acquiring HIV. Before we can have a vaccine that protects everyone around the globe, we need volunteers locally who are willing to step forward to participate in clinical trials and help reach this goal.