Smallpox Vaccine May Prevent Spread of HIV, Study Shows

Posted: May 24, 2010 at 1:05 am, Last Updated: May 21, 2010 at 3:40 pm

By Marjorie Musick

Raymond Weinstein

Could the end of the smallpox epidemic have contributed to the spread of HIV years later? One Mason researcher has spent the last several years investigating this possibility.

Raymond Weinstein, research professor in the Public and International Affairs Biodefense Program, recently concluded a study that suggests that the eradication of smallpox and the end of smallpox vaccination in the mid-20th century may have caused a loss of protection that contributed to the rapid spread of HIV in the 21st century.

The results of the investigation – conducted in collaboration with researchers from George Washington University, the University of California at Los Angeles and AFG Biosolutions – were published on May 18 in the open source journal BMC Immunology.

According to Weinstein, who was the study’s principal investigator, the relatively sudden appearance and explosive spread of HIV throughout Africa and around the world beginning in the 1950s has never been adequately explained.

“There have been several proposed explanations for the rapid spread of HIV in Africa, including wars, the reuse of unsterilized needles and the contamination of early batches of polio vaccine. However, all of these have been either disproved or do not sufficiently explain the behavior of the HIV pandemic,” says Weinstein.

Theorizing that this phenomenon may be somehow related to the eradication of smallpox and the end of public vaccination against the disease, the researchers took white blood cells from patients who had been vaccinated against smallpox within the previous three to six months, and also from patients who had never been vaccinated.

The cells were then infected with different strains of HIV and monitored over a 12-day period to see how well the infected cells were able to reproduce.

The researchers found that the HIV introduced into cells from unvaccinated subjects thrived while the HIV in cells taken from vaccinated patients had great difficulty replicating itself, showing a five-fold reduction when compared to the unvaccinated subjects.

“Although further research is needed, if our results can be replicated and confirmed, it could mean that the smallpox vaccine may be clinically useful to prevent HIV infection and suppress the virus in those already infected. We hope this research will open the doors to an effective and inexpensive weapon against the devastating AIDS epidemic,” says Weinstein.

Michael M. Weinstein of UCLA, Kenneth Alibek of AFG Biosolutions and Michael I. Bukrinsky and Beda Brichacek of George Washington University collaborated on the project. This research was funded solely by the authors.

BMC Immunology contributed to this report.

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