Steve Quayle News Alerts

July 7, 2002
By Maggie Fox, Health and Science Correspondent

WASHINGTON (Reuters) - Mass vaccination would save thousands more lives in a smallpox attack than the current limited strategy that has been recommended to the U.S. government, experts said on Sunday.

In a study criticizing the limited vaccination plan, they recommended federal officials be ready to vaccinate millions of people.

"Mass vaccination really leads to fewer deaths than the CDC (Centers for Disease Control and Prevention nterim plan," Lawrence Wein of the Massachusetts Institute of Technology, who worked on the study, said in a telephone interview.

Besides, he said, if there were a smallpox attack, "I think it highly likely that people would take to the streets to demand vaccination, or would flee," possibly spreading the disease even more widely.

Wein and Edward Kaplan of Yale University, both experts in modeling epidemics, published their study in Tuesday's issue of the Proceedings of the National Academy of Sciences and urged the CDC to change its current policy when it issues new guidelines later this year.

Smallpox, once a scourge that killed nearly a third of its victims and scarred the rest, was eradicated in 1979. But some countries, including Iraq and the former Soviet Union, experimented with the virus as a potential germ warfare agent.

Fearful of a smallpox attack, the U.S. government last year ordered millions of doses of smallpox vaccine -- enough, in the words of Health and Human Services Secretary Tommy Thompson, to vaccinate "every man, women and child" in the country.

PLANS FOR VACCINATING 500,000 REPORTED

Government advisers last month said a so-called ring vaccination strategy, which would involve finding and vaccinating people who had contact with an infected person, would probably be sufficient in case of an attack. More people could be vaccinated if this approach failed, they said.

They also recommended vaccinating potential first-line responders now as a precaution. On Sunday, The New York Times reported the federal government was planning to vaccinate 500,000 health care and emergency workers soon.

The newspaper quoted federal officials as saying the government was laying plans for a mass vaccination of the population, just in case.

But a U.S. Health and Human Services Department spokesman, Bill Pierce, told Reuters the exact number of those to be vaccinated had not yet been decided.

Pierce said these recommendations were very general and required more work by HHS and the Centers for Disease Control to identify which groups should be vaccinated.

The ring vaccination policy was used in the 1970s to eradicate the virus, which lives only in people, in the last few places where smallpox infection remained.

Kaplan said current policy is based in part on this past success.

"But it is one thing when ring containment means putting a ring around a village ... as opposed to trying to put a ring around New York City," Kaplan said in a telephone interview.

Kaplan and Wein ran a computer model of what would happen if someone used a smallpox weapon against a city of 10 million people. Kaplan told an advisory meeting on smallpox vaccine that an initial 1,000 infections could lead to 97,000 deaths.

SIDE-EFFECTS

Ring vaccination would lead to 4,000 more deaths than mass vaccination would, they predicted -- even taking into account a high rate of side effects from the vaccine.

"We tried to take into account the likely number of people that you would have running around tracing and vaccinating," Kaplan said in a telephone interview.

"What if you can't identify everybody?" People can be ill with smallpox and pass on the virus before they develop the distinctive blisters, Kaplan pointed out. "The disease doesn't stand still and wait for you to intervene."

Since vaccination was scrapped in the United States in 1972, experts assume almost no one has any real immunity any more. This means smallpox, which is highly infectious, could spread like wildfire through the population.

But the current vaccine is based on old technology and is not considered very safe. It has a high rate of side-effects, some of them deadly.

In addition, more people have suppressed immune systems now than in the 1970s, and they could be at special risk not only from the vaccine, but from people recently immunized with it.

Such people include cancer patients being treated with chemotherapy and people infected with the AIDS virus.

The current CDC policy, endorsed by the Advisory Committee on Immunization Practices last month, takes this into account. It calls for quarantining anyone confirmed to have been infected in a smallpox attack.

Anyone who may have had contact with the infected patients would be tracked down and vaccinated.

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