Did the end of smallpox vaccination cause the explosive spread of HIV?

May 17, 2010

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, USA, worked with a team of researchers from George Washington University and UCLA. The researchers looked at the ability of taken from people recently immunised with vaccinia to support compared to unvaccinated controls. They found significantly lower 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 . 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 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Smallpox immunization was gradually withdrawn from the 1950s to the 1970s following the worldwide eradication of the disease, and HIV has been spreading exponentially since approximately the same time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".

Explore further: Cell-associated HIV mucosal transmission: The neglected pathway

More information: Significantly Reduced CCR5-tropic HIV-1 Replication in vitro in Cells from Subjects Previously Immunized with Vaccinia Virus, Raymond S Weinstein, Michael M Weinstein, Kenneth Alibek, Michael I Bukrinsky and Brichacek Beda, BMC Immunology (in press), www.biomedcentral.com/bmcimmunol/

add to favorites email to friend print save as pdf

Related Stories

Herpes drug inhibits HIV replication, but with a price

Nov 06, 2008

The anti-herpes drug acyclovir can also directly slow down HIV infection by targeting the reverse transcriptase (RT) enzyme, researchers report in this week's JBC. This beneficial effect does pose a risk though, as HIV-in ...

Scientists find another key to HIV success

Mar 22, 2006

Weill Cornell Medical College scientists say they've determined a protein produced by HIV infected cells prevents immune B cells from producing antibodies.

Exhausted B cells fail to fight HIV

Jul 14, 2008

HIV tires out the cells that produce virus-fighting proteins known as antibodies, according to a human study that will be published online July 14 in the Journal of Experimental Medicine.

Recommended for you

Cambodia orders probe into mass HIV infection

Dec 18, 2014

Cambodian Prime Minister Hun Sen on Thursday ordered a probe into an apparent mass HIV infection believed to have been spread by contaminated needles, as the number of suspected cases passed 100.

A fresh setback for efforts to cure HIV infection

Dec 17, 2014

Researchers are reporting another disappointment for efforts to cure infection with the AIDS virus. Six patients given blood-cell transplants similar to one that cured a man known as "the Berlin patient" have ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.