If new research on smallpox and its relationship with AIDS bears fruit, parents may be adding one more vaccine to the arsenal of shots their kids get. The BBC reports that the vaccine used to wipe out smallpox offered some protection against the AIDS virus. Some scientists believe its disuse since smallpox was eradicated has helped the rapid spread of AIDS.
Smallpox inoculation was the very first form of vaccination. First practiced in Africa, the technique was adopted by Boston firebrand preacher and politician Cotton Mather and spread to Western medical doctors after it helped quell an outbreak of smallpox in Boston.
Not only is smallpox vaccination old, it’s remarkably effective. Smallpox remains the only vaccine preventable illness to have been completely eradicated, in spite of massive efforts to wipe out polio and measles.
A recent study showed that HIV replication in white blood cells taken from people who had recently received the smallpox vaccine is drastically reduced. In the vaccinated blood cells, HIV replicated five times more slowly than in the non-vaccinated ones.
Some researchers believe that phasing out the smallpox vaccine in the 1970s, following the eradication of smallpox, may have helped the spread of HIV. From the BBC:
The researchers believe vaccination may offer some protection against HIV by producing long-term alterations in the immune system, possibly including the expression of a receptor called CCR5 on the surface of white blood cells, which is exploited by the smallpox virus and HIV.
Jason Warriner, clinical director for the Terrence Higgins Trust, said: “It’s impossible to say whether the withdrawal of the smallpox vaccine contributed to the initial explosion of HIV cases worldwide, but it is a plausible explanation.
No one is suggesting, now, that we start using smallpox vaccine as a weapon to fight AIDS. But this study opens up more avenues for research, and gives scientists a potential tool in an expanding arsenal to deal with the pernicious disease.
For now, they stress that our focus as individuals should remain on preventing HIV from being passed person to person in the first place.