That scar on your arm won't help if the man next to you is infected.(Brief Article)

2002 JUN 19 - (NewsRx.com & NewsRx.net) -- If you had a smallpox vaccination as a child and think you're still protected, think again. Almost everyone vaccinated before smallpox was eradicated in the mid-1970s has now lost their immunity.

The bad news comes from a study of 621 microbiologists in Maryland who received fresh vaccinations between 1994 and 2001 to protect them in their work. Only about 40, or just 6%, were still immune from their earlier vaccinations. The report was published in the Spring 2002 issue of Maryland Medicine and reviewed in the June 1, 2002, issue of New Scientist.

"The study is, to the best of my knowledge, the only one since eradication which tries to look at the durability of immunity," said lead author Michael Sauri, director of the Occupational Medicine Clinic in Maryland. "It's showing us that after 20 years immunity is not going to be there."

In the U.S., for example, about 60% of the population has had a smallpox vaccination. The study suggests that most of these people are now just as susceptible to smallpox as the 120 million born since the government halted vaccination in 1972.

That strengthens the case for preemptive immunization, some experts think. "It adds to the argument that you can't count on any protection we thought we had," said Bill Bicknell of Boston University, a former commissioner of the Massachusetts Department of Public Health who has been arguing for mass vaccination since the anthrax attacks, in case terrorists try smallpox next.

He thinks that outbreaks would be much easier to contain if almost everyone is vaccinated. "I'm not saying you just ...