- HIV has so far defeated the best efforts of vaccine scientists because the virus evades and undermines the immune system.
- If HIV infection cannot currently be prevented, a second goal of vaccine makers is to reduce the virus’s spread and the severity of illness it causes.
- Researchers are already returning to basic science to follow new leads, and are far from giving up.
Not long after the virus that causes AIDS was identified, Margaret Heckler, then the U.S. secretary of health and human services, told a group of reporters that the discovery would enable scientists to develop a vaccine to prevent AIDS. “We hope to have such a vaccine ready for testing in approximately two years,” she declared proudly. It was 1984.
Government officials have certainly been spectacularly wrong on other occasions but rarely has a large portion of the scientific community been so overly optimistic as well. Twenty-five years after isolating HIV, we still have no effective vaccine. One year ago a major clinical trial of a candidate made by Merck was shut down because it became obvious that the vaccine was not working and might even be doing harm. This past summer another vaccine hopeful was shelved and its trial canceled before it could begin because there was no reason to believe its results would be any better.