The smallpox vaccine may help protect people against the AIDS virus, U.S. researchers said on Thursday. A team at Virginia’s George Mason University said they had shown, in lab dishes, that blood cells from people vaccinated against smallpox were four times less likely to become infected by the AIDS virus.
They are now negotiating with Acambis Plc, which makes vaccines against smallpox and other diseases, to test their idea further.
“Our outcomes are very encouraging,” Ken Alibek, a bioterrorism and smallpox expert at George Mason, said in a statement. “Additional studies that may lead us to more definitive conclusions already are under way.”
Many researchers have proposed links between protection against smallpox and against the AIDS virus. Some studies have noted that older people who were vaccinated against smallpox were also less likely to contract HIV.
A study published in 1999 showed that a relative of smallpox, called the myxoma poxvirus, uses the same cellular doorway — the CCR5 receptor — to infect a cell as AIDS does.
And studies have noted that people with certain mutations in CCR5 are resistant to HIV infection.
Alibek, Raymond Weinstein and colleagues at George Mason used these studies as the basis for their experiment, said Jerry Coughter, director of life science management at the university.
They took the blood of 10 people vaccinated against smallpox and 10 people who had never been vaccinated against smallpox, and exposed both batches to the HIV virus that causes AIDS.
“They saw an average four-fold reduction in infectivity,” Coughter said in a telephone interview.
More studies needed
The study results have not been subjected to a peer review, in which other experts examine the data and find potential flaws. Coughter said the findings had been submitted to a scientific journal as a first step in this process.
HIV infects an estimated 43 million people worldwide and has killed 28 million. Work on a vaccine so far has failed to produce a shot that protects against infection.
Smallpox was eradicated in 1979 through a global vaccination effort. Hundreds of millions of people have been vaccinated against the virus and the United States and other countries have resumed limited vaccination campaigns because of fears the deadly virus could be used as a biological weapon.