Researchers are currently debating whether the smallpox vaccine could prevent HIV in humans. This new idea is based on a preliminary study conducted by scientists at George Mason University.
Researchers Raymond Weinstein and Ken Alibek introduced HIV into blood samples from 10 people who received the smallpox vaccine and 10 people who did not. The blood samples of those who had been vaccinated showed either slowed growth or the absence of HIV altogether.
According to Alibek, the results were statistically significant despite the small sample size.
The researchers based their study on the hypothesis that the spread of HIV in Africa in the 1980s coincided with the decline of the number of people receiving smallpox vaccinations.
William Weidanz, University of Wisconsin professor of immunology, disagreed with the basis of the researchers’ hypothesis.
“It is true that the decline of smallpox vaccinations coincided with the spread of AIDS in Africa, but these are unrelated events,” said Weidanz, adding that he believes these incidents are merely a correlation.
Until recently, the smallpox vaccine had not been used since smallpox was declared eradicated in 1980.
Since Sept. 11, 2001 and the increased threat of bioterrorism, President Bush announced revival of the vaccinations for health care workers in late 2002.
Smallpox vaccinations contain a live virus called vaccinia, which is related to smallpox but cannot actually cause the virus. The vaccinia is a milder type of pox virus that helps the body develop immunity to the smallpox virus.
Smallpox vaccinations are not recommended for the general public because the vaccine causes greater risks than other vaccines.
According to the Center for Disease Control, 1.5 out of 1 million people die as a result of life-threatening reactions to the vaccine. There are also several side effects, such as heart inflammation and general cardiovascular problems.
“One of the biggest fears is that the smallpox immunization could kill HIV patients,” said Weidanz.
HIV patients and individuals undergoing cancer treatment or organ transplants are at a greater risk of negative effects from smallpox vaccinations because of their lowered levels of immunity.
As a result, some scientists are not convinced the findings of this new study will be useful to those with HIV.
“People with HIV have no immune response, and so the chance of getting vaccinia is great,” Dr. Judith Manning, UW professor of immunology, said.
Some researchers are also skeptical of the study because it has not yet been published in a scientific journal. There has been no formal committee to review and challenge the research, so it is quite controversial, Weidanz said.
Based on the initial experiment, George Mason University has filed a patent application on the therapeutic use of the smallpox vaccine for HIV. The researchers are currently collaborating with George Washington University in an effort to put together plans for a new experimental design.
The scientists plan to test the vaccine’s action against HIV and will ultimately determine if a simple smallpox-vaccine shot could prevent AIDS.
“We need to test our previous findings to see if we can repeat it. We also need to determine how this occurred and what mechanisms are involved. It should be very interesting,” said Alibek.
In order to prove that a smallpox shot can prevent HIV, researchers must continue to study the mechanism of action within their current findings.
“Of course there is always a possibility that there may be something more substantial behind the story. Nature and science can be quite unpredictable, but at the moment I would say that this possibility is about as probable as you or me winning the jackpot in the Wisconsin lottery … but, sometimes people win jackpots,” UW professor of medical microbiology and HIV researcher Mirek Malkovsky said.
