LOS ANGELES — The worldwide eradication of smallpox in the mid-20th century was a remarkable achievement, but it may have set the stage for the HIV pandemic of the latter half of the century, researchers reported Tuesday.
Laboratory tests suggest that immunity to smallpox triggered by the vaccine for the disease can inhibit the replication of the AIDS virus. Such vaccination could have kept HIV transmission partially under control in the early days of the outbreak, but withdrawal of the smallpox vaccine in the 1950s would have freed it to spread unfettered, the researchers said.
The most common form of HIV is thought to have evolved from a simian immunodeficiency virus found in chimpanzees of southern and western Africa sometime around 1931. It spread slowly until the mid- to late 1950s, when it began to spread exponentially.
Dr. Raymond S. Weinstein of the biodefense program at George Mason University in Manassas, Va., reported in the journal BMC Immunology that HIV replication was slowed by about 80 percent in white blood cells from people who had received the smallpox vaccination. “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,” Weinstein said.
