TCS Daily

SARS, Schmars

By Henry I. Miller - May 9, 2003 12:00 AM

Sixty one percent of Americans would opt for smallpox immunization if the vaccine were available, according to a nationwide survey late last year by the Harvard School of Public Health. However, the vaccine has long been known to be dangerous, and the most recent data suggest that it is even more hazardous than previously predicted.

This is a prescription for bad medicine.

Medically and epidemiologically, smallpox is the most feared and potentially devastating of all infectious agents. Far more contagious than SARS, for example, it spreads readily from person to person via droplets coughed up by infected persons, through direct contact, and from contaminated clothing and bed linens. Smallpox is fatal in approximately one-third of previously unvaccinated persons who contract the disease, compared to four to six percent for SARS, and 0.1 percent for hepatitis A and B.

The Bush administration, Congress and the media have raised the specter of terrorists using smallpox virus as a weapon, and the government has obtained sufficient vaccine for every man, woman and child in this country. (Routine smallpox vaccinations ceased here in 1972.) The administration has begun to vaccinate 500,000 health care workers, and has announced that the vaccine will eventually be made available to the population at large.

But the vaccine may be more of a threat to public health than smallpox itself.

The vaccine consists of live vaccinia virus, a close relative of smallpox. Highly impure and crude by the modern standards of gene-spliced vaccines such as those that have been successfully deployed against hepatitis B since the 1980s, the vaccine is not much improved from the one introduced by the English physician Edward Jenner in the eighteenth century.

During its use in the decades before 1972, smallpox vaccine was known to provoke various serious side effects, including rashes; spread from the inoculation site to face, eyelid, mouth or genitalia; and generalized infection. The data suggested that of every million vaccinees, approximately 1,000 in a million would experience serious side-effects, 15 of which would be life-threatening; three would develop encephalitis, which can lead to permanent neurological damage; and between one and three would die. People whose immune systems were suppressed, or who had ever had eczema, were at the highest risk of side effects.

Data just released by the CDC suggest that the 30-plus-year-old vaccine may be even more dangerous now. Of the approximately 33,400 health are workers who have received the vaccine, 45 have experienced serious side-effects. Extrapolated, that means that of every million vaccinees, we would expect to see more than 1,300 serious side-effects. So if the 61 percent of the eligible population who say they want the vaccine were to get it, we would expect about 165,000 serious side effects, and 250 to 300 deaths. (To put this into perspective, as of May 5th, SARS had caused 61 illnesses and no fatalities in the United States.)

The CDC has also revealed that 103 expectant mothers received the smallpox vaccine, even after being warned about possible dangerous side effects. This is alarming because the vaccine can cause an infection known as fetal vaccinia, which can kill the unborn or newborn baby, or cause premature birth.

Worse still, the CDC's findings disclose completely new kinds of adverse effects: Ten persons have experienced myopericarditis, an inflammation of the heart muscle or the sac that surrounds the heart, and six have had heart attacks after being vaccinated.

Perhaps it is not surprising that the decades-old vaccine is more dangerous to today's population: Americans are older, and more are immunosuppressed as a result of HIV infections, cancer chemotherapy, organ transplants and steroid treatment. Even a small increase in the rate of side effects or mortality becomes significant when multiplied by hundreds of millions.

There are other problems with widespread vaccination besides the inevitable morbidity and mortality directly attributable to the vaccine. First, blood banks will not accept blood from persons for at least several weeks following vaccination or infection from exposure to a vaccinee.

Second, it is unclear who will bear the financial liability for damage to vaccinees, or to persons secondarily infected by exposure to vaccinees. (The Bush administration's remedy was to propose a scheme for compensating persons injured by smallpox vaccination. However, it does not define rigorously and scientifically the circumstances and timeframes of injuries that are likely to be related to the vaccine; and without these scientific definitions, the administration's plan creates yet another open-ended federal entitlement program - the last thing we need at a time of skyrocketing health care costs and federal deficits.)

Third, persons who receive the smallpox vaccine will develop a long-term immunity that will interfere with poxvirus-based treatments now being developed against HIV and various cancers.

We are being penalized once again by the law of unintended consequences.

If re-emergence of smallpox were likely, widespread vaccination would be appropriate. However, smallpox virus no longer occurs in nature but is limited to two known, legitimate repositories, one in the United States, the other in Russia (and perhaps to illegitimate ones in several other countries). It is very difficult to obtain, and to cultivate and disseminate.

Also, smallpox is not immediately contagious after infection. It can be transmitted from one person to another only after an incubation period and the appearance of the characteristic rash, by which time the victim is prostrate, bedridden and probably hospitalized. Therefore, the much-publicized scenario in which suicide terrorists infect themselves and then spread the disease widely through the population is not a realistic one.

Moreover, although universal smallpox vaccination was phased out throughout the world during the 1970s, individuals who were vaccinated prior to that time retain significant immunity from these immunizations, both against contracting the disease and against a fatal outcome in case of infection. Scientists know a great deal about the long-term retention of immunity from a landmark study of 1,163 smallpox cases in Liverpool, England in 1902-1903. Among those infected, seven percent of the people 50 or older who had received the vaccine as children experienced severe disease and death, while 26 percent of unvaccinated people in that age group contracted serious cases of smallpox and all died.

Even if an outbreak were to occur, public health authorities know how to respond. Control depends upon early detection, quarantine of infected individuals, surveillance of contacts, and focused, aggressive vaccination of all possible contacts - an approach dubbed "quarantine-ring vaccination."

Finally, the federal government has taken steps to cope with the possibility of a terrorist attack involving smallpox, by educating doctors to recognize the disease and by vaccinating small teams of experts who can rush to any part of the country to confirm the diagnosis, and contain and treat an outbreak. One important lesson that SARS has taught us is the importance of a rapid, well-coordinated, and systematic response to outbreaks of serious infectious diseases.

It is imprudent to inoculate widely against a non-existent disease with a vaccine that has serious and frequent side effects. Better to immunize only a minimum of government first-responders and hospital workers who would be involved in a reported outbreak, then vaccinate more widely if an actual case is found. Any other course of action would be driven more by public relations than public health.

Sherlock Holmes admonished in A Scandal in Bohemia that "it is a capital mistake to theorize before one has data." It is worse to make the wrong decision after one has data.

Henry I. Miller, a physician, is a fellow at the Hoover Institution and the author of To America's Health: A Proposal to Reform the Food and Drug Administration. He was an official at the FDA from 1979-1994.

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