A SHOT IN THE DARK: SWINE FLU'S VACCINE LESSONS
06 Nov 2002
Source: Washington Post, May 27, 2002.
A Shot in the Dark: Swine Flu's Vaccine Lessons
By David Brown, Washington Post Staff Writer
Twenty-six years ago, the United States government got word that a deadly virus nobody had seen for years -- and which experts thought was gone forever -- was possibly circulating again.
There wasn't any proof it was back, just a few worrisome hints. However, the microbe had killed millions of people earlier in the century, so even a small amount of evidence had to be taken seriously. So, at great effort and expense, the government launched a plan to vaccinate the American population against the virus.
It seemed like a good idea at the time. But it turned into one of the biggest public health debacles in memory.
The disease was swine flu, whose appearance in 1976 was believed to be a reincarnation of the infection that killed tens of millions of people in 1918 and 1919. Today, the U.S. government is engaged in similar deliberations about smallpox, a disease officially eradicated in 1980 but whose virus some experts believe may be possessed by terrorists.
Over the next month, a panel of scientific experts convened by the Centers for Disease Control and Prevention (CDC) will debate the value -- and hazards -- of making the smallpox vaccine available in the United States for the first time in 30 years. Universal vaccination is out of the question, but widespread distribution is possible. By the end of June, the experts will recommend a course of action to the Bush administration.
Influenza and smallpox -- and their vaccines -- differ in innumerable ways, making comparisons tricky. Influenza occurs naturally and spreads quickly. Smallpox hasn't existed outside of laboratory freezers since 1978, but might be in terrorist arsenals. The flu vaccine has few serious side effects, while the smallpox vaccine has many.
Nevertheless, the swine flu campaign is the one recent example of a large, government-sponsored emergency immunization program, and as such may offer lessons for today.
Events began with the death, on Feb. 4, 1976, of an Army recruit at Fort Dix, N.J., during an outbreak of respiratory infections following the holidays. Throat washings were taken from 19 ill soldiers, and a majority tested positive for that winter's dominant strain of the influenza virus, which was called A/Victoria. But four samples were different, and New Jersey public health officials sent them to the CDC to be identified.
On Feb. 12, the CDC delivered a chilling report. The four samples -- which included one from the dead soldier -- were swine flu. As the name suggests, swine flu was endemic to pigs. However, the devastating pandemic of the Spanish flu in 1918 and 1919 is believed to have been caused by a strain of swine flu that, through mutation, gained the ability to infect people.
In 1927, a scholar put the Spanish flu's global mortality at 21.5 million. In 1991, a systematic recalculation raised it to 30 million. The latest estimate, published in the current Bulletin of the History of Medicine, sets the minimum mortality at 50 million, with an upper limit of 100 million.
The possibility that the Spanish flu had reemerged was a matter whose importance is hard to overstate -- and wasn't missed by anyone in 1976. Within days of identifying the strain, federal health officials were meeting at the CDC to discuss what to do.
According to various accounts, the idea that a swine flu epidemic was quite unlikely never received a full airing or a fair hearing, although numerous experts apparently held that view. Instead, the notion that an epidemic was likely enough to warrant population-wide vaccination grew from dominant opinion to unquestioned gospel.
At the same time, the rhetoric of risk suffered steady inflation as the topic moved from the mouths of scientists to the mouths of government officials. In a memo prepared for his superiors at the Department of Health, Education and Welfare (HEW), David Sencer, head of the CDC, talked about the "strong possibility" of a swine flu epidemic. Later, HEW's general counsel commented that "the chances seem to be 1 in 2." A memo from the HEW secretary to the head of the Office of Management and Budget noted that "the projections are that this virus will kill one million Americans in 1976."
A few experts suggested the vaccine be made and stockpiled but used only if there was more evidence of an epidemic. This was considered but rejected early on. The argument was that the influenza vaccine had few, if any, serious side effects, and that it would be far easier (and more defensible) to get it into people's bodies before people started dying.
On March 24, President Gerald Ford announced on television that he was asking Congress for $135 million "to inoculate every man, woman and child in the United States" against swine flu.
Over the next nine months, very little went right -- or as planned.
Pharmaceutical companies undertook crash programs to make enough of the vaccine by the start of flu season in October. But it turned out the Fort Dix bug grew poorly in chicken eggs, the growth medium for the influenza virus. This meant that yields were going to be about half of what was planned. In addition, one company used the wrong virus and had to start over.
The insurance industry announced it wouldn't insure manufacturers against liability arising from the vaccine. An act of Congress shifted most of the liability to the government.
Studies of Fort Dix's soldiers showed that about 500 had been infected with swine flu. But with only one death, this called into question the deadliness of the strain. In addition, swine flu didn't appear that summer in the Southern Hemisphere, as would be expected if a pandemic were starting.
Tests showed that single injections of some vaccine formulations didn't protect children. This required time-consuming studies of a two-shot regimen.
Albert Sabin, the father of the oral polio vaccine and a high-profile advocate, broke with the party line and called for stockpiling, but not immediate use, of the vaccine.
Three elderly people in Pittsburgh died on the same day within hours of getting swine flu shots. It was a chance event, but just the sort of guilt by association that arises whenever a public health intervention is done on a mass scale.
What killed the program, though, was the observation in early December that people given the swine flu vaccine had an increased risk of developing Guillain-Barre syndrome, a rare, usually reversible but occasionally fatal form of paralysis. Research showed that while the actual risk for Guillain-Barre was only about 1 in 1,000 among people who had received the vaccine, that was about seven times higher than for people who didn't get the shot.
On Dec. 16, the swine flu vaccine campaign was halted. About 45 million people had been immunized. The federal government eventually paid out $90 million in damages to people who developed Guillain-Barre. The total bill for the program was more than $400 million.
There are a lot of lessons to draw, said Harvey Fineberg, a former dean of Harvard's School of Public Health, who co-authored an analysis of the "swine flu affair" for Joseph A. Califano, HEW secretary under President Jimmy Carter, who succeeded Ford in January 1977.
Among them: Don't over-promise; think carefully about what needs to be decided when; don't expect the consensus of experts to hold in the face of changing events. The biggest, he said recently, was perhaps the most obvious: Expect the unexpected at all times.