10 May 2004

Anti-Vaccination Fever

The January 2004 issue of Skeptical Inquirer ran a report by William John Hoyt, Jr., under the title "Anti-Vaccination Fever: The Shot Hurt Around the World":
Sensationalist media, religious fanatics, and alternative medical practitioners fanned the fires created by questionable research to spawn worldwide epidemics of a disease that had almost been forgotten.
"A poignant television story of a victim of a rare reaction to a vaccine can render invisible the vast good brought about by this same vaccine." -- John Allen Paulos
When pertussis takes hold, the infected person makes horrid, whooping sounds as he inhales. When he gets a chance to inhale. Which isn't often during the torturous "paroxysmal phase," characterized by sudden attacks of repetitive, severe coughing. The disease's Latin name, pertussis, translates as "intensive cough." But whooping cough, the common name, does a far better job of describing the unique whooping sound the disease's victim makes when, finally, he gets a chance to breathe....

You have probably imagined an adult victim while reading thus far. In fact, before an effective vaccine became available, pertussis had been a worldwide leading cause of infant deaths. Before the 1940s, it was a major cause of infant and child morbidity and mortality in the U.S. (CDC 2002). From 1890 to 1940, in New South Wales, whooping cough killed more children under five than diphtheria. It was second only to gastroenteritis as a cause of infant deaths (Hamilton 1979)....

Fear and Loathing on the Vaccine Trail

In 1906, researchers discovered that the Bordatela pertussis bacterium caused pertussis. Within twenty years of that discovery, the first whole-cell pertussis vaccine was developed (Research Defence Society 1999). After two decades of testing and refinement, many countries accepted varying versions of a whole-cell pertussis vaccine, established vaccination protocols, and began to vaccinate their citizens. Many of the vaccine manufacturers produced a combined diphtheria-tetanus-whole cell pertussis (DTP) vaccine.

For most countries, as vaccination coverage increased, both the frequency and severity of pertussis epidemics markedly declined. Ironically, this success actually may have been the vaccine's undoing, as presaged in this pointed 1960 British Medical Journal commentary: "When immunization results in the virtual elimination of a disease it is inevitable that some will question the continued need for routine inoculation of all infants" (Editors 1960).

The first hint of a problem came from Sweden in 1960, less than ten years into its vaccination program. Sweden had previously seen pertussis incidence rates as high as nearly 300 per 100,000. By 1960, the incidence rates were merely a third of that and falling (Gangarosa et al. 1998). It was at this time that Justus Ström, an influential Swedish medical leader, questioned the continuing need for pertussis vaccines. In his British Medical Journal paper, he claimed pertussis was no longer a serious disease because of economic, social, and general medical progress. Furthermore, he cited thirty-six cases of neurological conditions that he attributed to the whole cell pertussis vaccine, calculating an alarming neurological complication rate of 1 in 6,000 (Ström 1960)....

Then in the United Kingdom, in 1974, Kulenkampff and his colleagues published a paper citing another thirty-six cases of neurological reactions that they attributed to the whole cell pertussis vaccine. The paper's evidence was weak on several fronts acknowledged by the authors. They clearly stated they "do not know either the prevalence of natural infection or the frequency of inoculation encephalopathy (brain diseases resulting from vaccination) in the population we serve" (Kulenkampff et al. 1974). And they noted that "in as many as a third of our patients there were contraindications to inoculation with pertussis vaccine, in that there was a previous history of fits, or family history of seizures in a first-degree relative; reaction to previous inoculation; recent intercurrent infection; or presumed neurodevelopmental defect" (Kulenkampff et al. 1974).

Despite the authors' appropriately cautious approach to their paper, the anti-vaccination advocates seized upon it, and the media ran with it. Soon after the paper's publication, British television aired a program on the whooping cough vaccine. Focusing on the anecdotal evidence of terrible adverse reactions supposedly caused by the vaccine, it presented little of the clear good the vaccine had done historically.

The negative press and television coverage persisted for years....
Brief summaries and graphs then detail how pertussis infection rates spiked to epidemic levels in countries where panicked medical establishments abandoned or severely cut back on vaccination programs.
Returning to the Status Quo Ante Botchum

The epidemics shocked many of the nations that experienced them, although official and public responses have varied. Many countries introduced acellular pertussis vaccine as a "safer" alternative to the whole-cell vaccine. Some have also tried to control the problem by introducing more vaccination boosters to the protocol. But other countries, those whose vaccination programs were unaffected by anti-vaccination movements, haven't experienced these epidemics at all. These countries include Portugal, Hungary, Norway, the former East Germany, Poland, and, until recently, the U.S.

Japan's reaction to its epidemic was swiftest and strongest. By 1981, Japan resumed vaccination with an acellular pertussis vaccine and pertussis incidence rates returned to their pre-fiasco levels. The United Kingdom's vaccine uptake rate began slowly climbing, and by the 1990s reached levels exceeding those prior to the hysteria. English and Welsh pertussis incidence rates declined accordingly.

Sweden, however, remains plagued with high pertussis rates. As recently as 1996, and despite continuing epidemics, Sweden had yet to resume vaccinations (Cherry 1996). Australia's efforts to halt pertussis continue to be thwarted by a passive anti-vaccination movement. The 2001-2002 epidemic bears witness to that. The Russian Federation has also failed to regain control and today has one of the highest pertussis incidence rates in the developed world.

Distorted numbers, confusion of correlation with causation, and statistical innumeracy certainly played roles in this sad story. Sensationalist media campaigns fanned the glowing embers. But in each of the countries that experienced the raging fires of epidemics there were other forces at work. Most prominent in passive anti-vaccination movements were religious groups whose opposition was based on religious or moral grounds. Prominent in both passive and active anti-vaccination movements are followers and practitioners of homeopathy, chiropractic, and natural and alternative medicine (Gangarosa et al. 1998)....

When anti-vaccination alarm takes hold--characterized by sudden attacks of the media, mistaken researchers, fervent religious groups, and alternative medicine quacks--the infected society begins to make horrid, whoppingly bad decisions. There is, as yet, no Latin name for this peculiar social disease.
via Arts & Letters Daily