CORRECTIONS APPENDED

The most cost-effective way to treat polio is to continue vaccinations until the virus has been eradicated, according to a study released yesterday by two researchers at the Harvard School of Public Health.

“As long as it is technically achievable, eradication offers both lower cumulative costs and cases than control in the long term, even with the costs of achieving eradication exceeding several billion dollars more,” Associate Professor of Risk Analysis and Decision Science Kimberly Thompson, one of the study’s authors, said a statement.

Since 1988 the number of polio cases worldwide has declined by 99 percent. The small number of cases has led some public health officials to suggest that it would be cheaper to treat the virus on an individual basis than to continue widespread preventive immunization.

Paralytic polio, the condition caused by the wild polio virus, claimed its last victim in the United States in 1979 and the number of incidents worldwide was under 2,000 in 2006, according to a statement from an earlier study. But the virus has yet to be eliminated in some parts of the developed world.

In countries like India, Nigeria and Afghanistan, the costs of ending vaccinations before eradication was achieved would be especially devastating, according to the study, which will appear in the April 21 issue of The Lancet.

“The implications of low control are lots of paralyzed children, which is something that people have to think about,” Thompson said in a joint interview with her co-author, Radboud Duintjer Tebbens. “Even though they won’t be in the U.S., we are talking about paralyzed children in the low income countries.”

In a similar study, published in December, Thompson and Tebbens, a research associate in the School of Public Health’s Department of Health Policy and Management, reported that the United States spent nearly $35 billion on polio vaccinations between 1955 and 2005. The researchers found that if vaccinations stopped, 1.1 million cases of the disease could erupt in the United States alone, ultimately costing the country $180 billion more than if the original policy were maintained. [SEE CORRECTIONS BELOW]

The authors conducted a cost-benefit analysis of economic data, running it through a computer model they had designed earlier.

“What we did in the study is go back and review the economic literature about eradication...and people have shown that it’s never optimal to do high control, you should either eradicate it or basically what you’re going to be doing is accepting low control,” Thompson said.

The debate between continued vaccination and treatment has gained momentum in recent years.

According to Thompson, “the fact that the eradication program has taken a long time and that the cost has been higher than some people have expected” has fueled the discussion.

“That’s led some people to question whether we should be spending so much money on polio,” she added.

The authors, who have worked together on polio since 2001, said their findings should inspire those fighting for polio vaccinations.

“My hope is that this study is one that helps people who have been committed to polio eradication and particularly the donors who appreciate the value of what they’ve done and the imporatance of a sustained commitment,” Thompson said. “My hope is that the study will reach those folks.”

CORRECTIONS

The April 12 news article "HSPH Study Backs Polio Eradication" misrepresented the findings of a School of Public Health study on the impact of polio vaccinations. The article stated that the study had found that “if vaccinations stopped, 1.1 million cases of the disease could erupt in the United States alone, ultimately costing the country $180 billion more than if the original policy were maintained.” In fact, the researchers determined that if the United States had ceased vaccinations, 1.1 million cases of the disease would have broken out in the United States alone. The breakout would have cost the country $180 billion in treatment costs, according to the study. [SEE CORRECTION BELOW]

An April 16 correction to the news article "HSPH Study Backs Polio Eradication" incorrectly stated that a breakout of the disease would have cost the United States $180 billion to treat. In fact, researchers determined that the United States had saved a net $180 billion by investing in polio vaccinations. In addition, the original story incorrectly implied that the study was similar to another published in December. The December study looked retrospectively at U.S. polio vaccinations, while the more recent study examined the issue prospectively.