The New York Times | October 23, 2005
By Andrew Pollack

PUBLIC health experts warn that the world might be close to a repeat of the flu pandemic of 1918, which killed millions. But could it instead be close to a reprise of the 1976 pandemic that never happened?

That is the year President Gerald R. Ford announced a crash program to "inoculate every man, woman and child in the United States" against swine flu. But the virus never became a killer, and vaccinations were halted two months after they began after reports that 500 people who received the shot developed a paralyzing nerve disease and more than 30 of them died.

If scientists were wrong in 1976, could they be wrong now? Some arguments being made about why a pandemic is looming echo those made three decades ago. But many experts say the situation now is different enough that a false alarm is less likely.

"We just know a lot more about the influenza virus than we did in 1976," said Ira M. Longini Jr., a professor at Emory University who is an expert on epidemics.

Still, a lot can be learned both from what did and did not happen back then.

The 1976 scare started in February when a handful of soldiers at Fort Dix in New Jersey got sick and one of them died. Scientists determined that the virus was one that infected pigs and was different from the human influenza viruses circulating then. On March 24, barely a month later, President Ford announced the vaccination plan.

One reason for the concern was that scientists thought the 1918 pandemic had been caused by a swine virus and that the Fort Dix outbreak marked its second coming. Furthermore, experts warned that pandemics tended to be cyclical and that another one was about due.

Today, thanks to genetic analysis - a technique not available in 1976 - scientists know the 1918 virus was a bird virus that mutated. So now there is concern that the H5N1 avian strain ravaging birds in Asia could in like fashion evolve into a form that can spread easily among people. The avian virus shows some mutations similar to those in the 1918 virus, said Jeffery K. Taubenberger of the Armed Forces Institute of Pathology. And experts are again warning that the world is overdue for a pandemic.

Edwin M. Kilbourne, a professor emeritus at New York Medical College who argued for the vaccination program in 1976, said there was actually less reason to be concerned about a pandemic today. That is because the swine flu virus at Fort Dix clearly passed easily from person to person, while the current avian flu has not.

Many experts disagree, however. In retrospect, they say, the 1976 decision to vaccinate was based on much less solid evidence than is available today.

"Part of the problem was convictions outpacing evidence," said Harvey V. Fineberg, president of the Institute of Medicine, part of the National Academies, and co-author of "The Epidemic That Never Was," a book about the 1976 experience. "I don't think that's happening today."

Even in 1976 there seemed to be more doubt than there is today about the issue. The World Health Organization and many European nations, for instance, did not see what the fuss was about. Today, they are busily preparing for a pandemic.

Doubts grew through the summer of 1976 when the virus was not detected outside Fort Dix. That first death turned out to be the only known one from the virus. Moreover, studies suggested that several hundred people at Fort Dix had been infected but most never got sick.

"That's very different from 120 cases with half the humans dying," said Dr. Fineberg, referring to the approximate toll so far from the Asian bird flu.

Perhaps the biggest mistake in 1976 was giving the vaccine to millions of people rather than just stockpiling it until clearer signs of an epidemic emerged. W. Paul Glezen, a professor at Baylor College of Medicine in Houston, said the prevailing belief was "we should use it because if it started spreading there wouldn't be time."

The vaccination program had problems. Production was delayed after one company produced the wrong vaccine. Another delay occurred when manufacturers demanded that Congress protect them from liability. Mass inoculations did not start until October, which might have been too late had a pandemic begun.

Still, by the time the program was halted in December, only 10 months after the virus was identified, about 150 million doses had been made and 45 million given.

There are lessons from 1976 that might be applied to today's preparations. A 2004 draft of a government plan for a pandemic listed some.

One is that "making clear what is not known is as important as stating what is known." Another is that a program should be re-evaluated periodically rather than left on autopilot.

And this time, federal officials said, the vaccine won't be used until there are signs a pandemic is under way.

Dr. Fineberg said another lesson is that Congress should provide liability protection for vaccine makers now, rather than waiting until the crisis occurs.

He said the wrong lesson to draw from 1976 would be "the superficially obvious one" - that because it didn't happen then it won't happen now and preparations are not necessary.

Still, repeated cries of wolf can make the public blasé.

"There's so much expectation for it to develop into a pandemic that if it does not in the next year or two it's quite possible you would see a backlash like the 1976 experience," said Dr. Taubenberger. "What I fear is that people would make the conclusion, falsely, that influenza is not such an important public health problem."