Polio’s return traced to lapses in India

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(This article was #60 in Discover Magazine’s top 100 stories of 2006.)

In May a 39-year-old man in Namibia tested positive for poliovirus, marking the country’s first case in 10 years. Since then, the outbreak there has reached 20 confirmed cases.

This year 10 other formerly polio-free countries are once again battling the disease. Genetic sequencing has traced cases in five of the countries, including Namibia, to a polio strain in India, where the virus remains endemic. As of October 2006, a total of 358 cases have occurred in the poor, densely populated north Indian state of Uttar Pradesh alone, up from 29 in 2005.

The World Health Organization has taken India to task, saying its outbreak is endangering efforts worldwide to keep the disease at bay. To protect a high-risk community from polio, at least 95 percent of the children must be vaccinated; but in late 2005 and early 2006 the vaccination rates in Uttar Pradesh dipped to between 85 and 90 percent.

The Indian government, vowing to eliminate polio by 2007, has discussed a pilot project using an injectable vaccine in addition to oral drops. The injectable vaccine is thought to offer better protection against polio infection in children with diarrhea, which is common in the area.

Fat vaccine works in rats

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(This article was #98 in Discover Magazine’s top 100 stories of 2006.)

In August, immunologist Kim Janda of the Scripps Research Institute grabbed headlines with reports of a vaccine against obesity. The vaccine triggers an immune response that targets ghrelin, a hormone naturally made in the gut and transported to the brain; ghrelin spikes with hunger and is thought to stimulate the storage of body fat.

In the study, rats that received the vaccine ate the same amount of food as the control group, but they gained less weight and had 20 percent less body fat. “I expected them to eat less, but it appears that what we saw was a result of metabolism,” Janda says. “Losing weight, losing fat—can’t ask for anything more than that!”

Now the reality check: The researchers followed the rats for only one week after the animals received their last booster shots. Long-term results could be very different. Michael Schwartz, professor of medicine at the University of Washington at Seattle, warns that the weight loss could prompt the body to compensate by making more of other weight-related hormones. Meanwhile, neuroscientist William Colmers of the University of Alberta worries about the wisdom of vaccinating the body against one of its own molecules. “It’s an intriguing idea, but it worries me considerably,” he says. “I sure as hell wouldn’t take it, no matter how fat I was.”