By Tracey Zhu
The Epoch Times
The public will not see any HIV vaccine or its human trial in the near future. This is the disappointing message that a panel of experts concluded at Health Journalism 2011 on April 16.
In the 1990s, when HIV was discovered, scientists were optimistic that a preventive vaccine would be developed soon to end the HIV pandemic, just like it was for polio. However, 30 years later, with the failure of the Thai trial and more understanding of the characteristic of the virus, doctors have realized that they are nowhere near that elusive goal.
"I do not see a vaccine in the next few years," said Jeffrey Jacobson, M.D., the chief of the Division of Infectious Diseases and HIV Medicine in Drexel University. "The monkey [animal] model is not helpful and the Thai trial has only provided weak signals if there is any," Dr. Jacobson said during the panel of discussion on "Developing HIV vaccine: Understanding the issues."
HIV has so many variations that the virus in each geographic area is different. One infected individual can have many different strains. Also, unlike other viruses, HIV destroys immune system cells that normally fight foreign invasions. These are two main reasons why it is so difficult for a vaccine to be developed for HIV, according to Steven D. Douglas, M.D., professor and associate chair in the Department of Pediatrics at University of Pennsylvania School of Medicine.
Roger J. Pomerantz, M.D., senior vice president of Merck Research Laboratories, echoed the opinion of two of his fellow panelists.
Merck had invested much funding in an experimental HIV vaccine that entered phase II clinical trial but was declared ineffective at preventing HIV infections in 2007. In the fall of 2009, the result of a trial of 16,000 people in Thailand was released with only 26 percent efficacy rate.
The results of the two trials might dash the hope of an HIV vaccine for the next several years. The three experts agreed but they think that more analysis needs to be done to learn from the human trials and basic research may offer more knowledge of the virus.
"The conventional way is not working," Jacobson said. "Maybe we need to look at things in a new way."
