Did the end of smallpox vaccination cause the explosive spread of HIV?
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https://www.sciencedaily.com/releases/2010/05/100517204405.htm
Vaccinia immunization, as given to prevent the spread of smallpox, produces a five-fold reduction in
HIV replication in the laboratory. Researchers suggest that the end of smallpox vaccination in the mid-
20th century may have caused a loss of protection that contributed to the rapid contemporary spread of
HIV–Did the end of smallpox vaccination cause the explosive spread of HIV?
Date:May 18, 2010 Source:
BioMed CentralSummary:
Vaccinia immunization, as given to prevent the spread of smallpox, produces a five-fold reduction in
HIV replication in the laboratory. Researchers suggest that the end of smallpox vaccination in the mid-
20th century may have caused a loss of protection that contributed to the rapid contemporary spread of
HIV.Share:FULL STORY
Vaccinia immunization, as given to prevent the spread of smallpox, produces a five-fold reduction in
HIV replication in the laboratory. Researchers writing in the open access journal BMC Immunology
suggest that the end of smallpox vaccination in the mid-20th century may have caused a loss of
protection that contributed to the rapid contemporary spread of HIV.
Raymond Weinstein, a family doctor turned laboratory scientist at George Mason University, Manassas,
Virginia, worked with a team of researchers from George Washington University and UCLA. The researchers
looked at the ability of white blood cells taken from people recently immunized with vaccinia to
support HIV replication compared to unvaccinated controls. They found significantly lower viral
replication in blood cells from vaccinated individuals.
Weinstein said, “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. Our finding that prior immunization with vaccinia virus may provide an individual
with some degree of protection to subsequent HIV infection suggests that the withdrawal of such
vaccination may be a partial explanation.”
Smallpox immunization was gradually withdrawn from the 1950s to the 1970s following the worldwide
eradication of the disease, and HIV has been spreading exponentially since approximately the same time
period. Weinstein and his colleagues propose that vaccination may confer protection against HIV by
producing long term alterations in the immune system, possibly including the expression of a certain
receptor, CCR5, on the surface of a person’s white blood cells which is exploited by both viruses.
Speaking about the results, Weinstein said, “While these results are very interesting and hopefully may
lead to a new weapon against the HIV pandemic, they are very preliminary and it is far too soon to
recommend the general use of vaccinia immunization for fighting HIV.”
Journal ReferenceRaymond S Weinstein, Michael M Weinstein, Kenneth Alibek, Michael I Bukrinsky and
Brichacek Beda. Significantly Reduced CCR5-tropic HIV-1 Replication in vitro in Cells from Subjects
Previously Immunized with Vaccinia Virus. BMC Immunology, 2010; (in press)