ON THE MARCH TO ERADICATE CHILD ILLNESS

Pneumococcus Streptococcus pneumoniae, also known as pneumococcus, kills more than 1 million children a year around the world. In the five years since Wyeth Pharmaceuticals won FDA approval for the pneumococcus vaccine Prevnar, the incidence of pneumococcal disease and related cases of meningitis among U.S. children under 2 has plunged by 80 percent, according to Peter Paradiso, a Wyeth vice president. Now the company is developing special formulations of the vaccine for the international market. Bacterial strains of pneumococcus vary from region to region around the globe. In April company researchers reported favorable results in Gambia. The U.S. price per dose is $50--more than a week's pay in Gambia--but Paradiso says the company is looking for ways to make the vaccine available to the world's poorest countries.

Malaria Of the more than 1 million people a year who die of malaria, 90 percent are under 5. "By the time kids are about 5, they've mostly built up their immunities," says Melinda Moree, director of the Malaria Vaccine Initiative. "They have malaria parasites in their bloodstream, but they're not sick." Last year researchers tested a GlaxoSmithKline vaccine on 1,000 children between 1 and 4 in Mozambique. It seemed to protect most recipients from severe illness, and it worked better in kids 2 and under than in the others. This summer, researchers will test it on infants. Moree thinks a working vaccine might be available in five years, but no sooner.

HPV Scientists at Merck Research Laboratories have almost finished testing a vaccine against human papilloma virus (HPV), which causes more than 99 percent of all cervical cancer. Up to 70 percent of all women are likely to catch the virus sooner or later without realizing it: although it's the world's most prevalent sexually transmitted disease, HPV has few symptoms aside from being a slow carcinogen. "Guys don't know they've got it. Girls don't know they've got it," says Dr. Eliav Barr, senior director of clinical research at Merck Labs. Because of the virus, one woman in four is likely to develop precancerous cells in the cervix at some point in her life. "If caught early, it's treatable," says Barr. And if not? Cervical cancer kills more than 200,000 women a year worldwide. Merck says its vaccine, in human trials since 1997, prevents 100 percent of the cervical precancers and occasional genital warts caused by the four most common HPV types. Merck is also testing the vaccine in men and evaluating whether it helps infected patients to fight the virus. The company expects to submit its findings to the Food and Drug Administration later this year; if the FDA approves, young people may be routinely immunized before they become sexually active.

TB Approximately one third of the entire human race is infected with tuberculosis, a disease that kills 2 million people a year, mostly in the Third World. It's a gruesome death: the disease slowly eats away the victim's lungs. Antibiotics can fight the pathogen, but resistant strains have sprung up. The first vaccine for TB, introduced in 1921, was never very effective. With backing from the Aeras Global TB Vaccine Foundation, researchers are working on a more effective vaccine, which might be available by 2013. It doesn't have to be perfect. Nine out of 10 carriers of the infection never develop the actual illness or the contagion that goes with it. Even a small improvement in the odds would be a big step toward eliminating the disease in much of the world.

Other challenges will be far tougher. The search for an AIDS vaccine has attracted far more public support than other major killers like TB and malaria, but medical researchers say it's still no more than a distant dream. "I'll be delighted if I see an effective HIV vaccine in my lifetime," says Lob-Levyt. "It's going to require the kind of scientific breakthrough where we're not even sure in which area that breakthrough would occur. It's probably one of the biggest challenges to science we have faced." Still, medical researchers have performed miracles before. A quarter century ago, they achieved the once unthinkable feat of completely eradicating smallpox. Within the next year or two, the polio virus should be similarly extinct. The important thing is to try.

© 2005