As the White House considers the Center for Disease Control’s proposal for smallpox prevention and control, Yale School of Management professor Edward Kaplan has joined other critics in asking the Bush administration to revise the CDC’s plan.

Kaplan said the CDC’s proposal to prevent and control an outbreak of smallpox would prove “inefficient and ineffective” in the event of an attack. Working with Stanford Business School professor Lawrence Wein, Kaplan has been using mathematical models to simulate terrorist-initiated outbreaks and to illustrate how smallpox would spread in a modern urban setting.

The researchers contend that more people should be vaccinated before an attack and that mass vaccination should be the first response to an outbreak.

Kaplan said the CDC plan assumes that the general population has a high level of immunity, that any outbreak would be small, and that one would easily be able to trace contacts of symptomatic cases. He added that the CDC plan is modeled after the “tail end” of the smallpox vaccination campaign that eradicated the disease.

CDC officials, although aware of Kaplan and Wein’s study, said they would not comment on it.

“The issue is being discussed at the highest levels of government,” CDC spokesman Curtis Allen said. “It’s not our policy to discuss other people’s studies.”

To prevent the rapid spread of the virus, Kaplan and Wein suggest 1.25 to 2.5 million “first responders” and vaccination clinic staff be inoculated. The CDC is currently suggesting that far fewer people — 510,000 — be pre-emptively vaccinated.

And if an attack does occur, Kaplan and Lawrence said mass vaccination should be the first response to any confirmed cases of smallpox. The CDC’s proposed strategy calls for “ring vaccination” before mass public inoculation.

Ring vaccinations — used during the global crusade against the disease in the 1970s and ’80s — isolate symptomatic smallpox victims and inoculate close contacts. The CDC’s plan only calls for mass vaccinations if ring vaccinations fail.

“It’s ring vaccination that is most helpful for actually cutting out transmission of the virus,” CDC National Immunization Program Director Dr. Walter Orenstein said during a teleconference last month.

Kaplan said he disagrees with Orenstein’s premise. What is wrong with that plan, he said, is that it presupposes smallpox would spread naturally — without the help of terrorists — as it did during the campaign against the disease two decades ago.

“It is an unbelievable translation of what worked 20, 30 years ago,” Kaplan said.

He added that in the time it would take to diagnose, isolate and vaccinate infected persons’ contacts, the disease might spread and cause more deaths — 4,102 in his simulation — than it would if everyone were vaccinated immediately.

“The same plan that worked in Bangladesh in the ’70s is not going to work in New York City in 2002,” Wein said.