Smallpox redux: world body suggests keeping the virus. (Science News This Week).

In response to fears following the Sept. 11 attacks, the executive board of the World Health Organization (WHO) last week voted against a 2002 deadline for destruction of the variola virus responsible for smallpox. Meeting in Geneva on Jan. 17, the board urged the United States and Russia to retain stocks of the virus so scientists can complete research on them.

Smallpox was a devastating disease for many centuries, and it still infected 50 million people annually during the 1950s. Following an intensified vaccination campaign and the successful worldwide eradication of the disease in the late 1970s, health officials prepared to destroy the last known stores of the virus--held in two top-security labs, one in the United States and the other in Russia.

However, many now fear that smallpox may have slipped into the hands of some other countries and terrorists. If so, destroying known samples would be a pointless exercise and, worse, would prohibit research and hobble future production of vaccines to guard against terrorist threats.

Six years ago, WHO's member nations resolved to destroy all stocks of the virus by June 1999 (SN: 6/8/96, p. 367). This deadline was later postponed until 2002. Now, WHO argues that critical research--on a monkey version of smallpox, new antiviral drugs, and an improved smallpox vaccine--won't be completed this year.

Several scientists said they support the new recommendation. "Certainly, we do need to improve the vaccine," says Jerry McGhee of the University of Alabama at Birmingham. If WHO can actually confirm that bioterrorists don't hold stocks of smallpox, it can reinstate plans to destroy variola, he says, but such confirmation will be "a daunting and difficult task, and it may never be accomplished."

To test the effectiveness of improved vaccines and drugs against smallpox, researchers need to infect test animals with the virus, agrees Samuel L. Katz, a specialist in infectious diseases at Duke University in Durham, N.C.

WHO's 191 member countries still have to accept the executive board's decision when they meet in May, although the assembly rarely rejects board proposals. No new target date for destruction of the virus has been set, but WHO requests that research be completed rapidly and plans to review the situation in 2 to 3 years.