Breaking the Cycle

And there is Brian Kiragu, who grew up in Kenya. Most of Kenya has high malaria rates, but Kiragu's family lived in Nairobi, whose high elevation and relatively mild temperatures have made life inhospitable for mosquitoes. Feeling lucky that he never contracted the disease, Kiragu would like to help his countrymen and other Africans. "If this vaccine we received doesn't work, it will at least get the doctors a step closer; they'll be able to rule out this approach," he says. "But what if it does work?" He chuckles at the boldness of the thought. "It would change everything."

THE QUEST TO DEFEAT MALARIA IS AN OLD ONE. Modern scientists started laying the groundwork a century ago. Optimism peaked in 1955, when the World Health Organization launched a malaria eradication campaign using insecticides such as DDT. Supported by foreign aid from governments and international organizations, the campaign largely overlooked Africa in favor of concentrating resources in Asia's more temperate subtropics, where mosquitoes were regarded as more vulnerable. Malaria rates quickly fell in targeted areas. But the malaria campaign waned, soon to be abandoned, when it became clear that the disease could not be altogether annihilated.

Malaria rates immediately rose again in Asia. In Africa, which had experienced some success in combating the disease on its own with pesticides and drugs, the death toll rose again in the 1980s, when the use of DDT in many countries was suspended under pressure from Westerners concerned about its impact on the food supply and environment. (WHO reversed its 30-year-old policy last month, declaring support for indoor spraying of DDT in malaria-prone regions.) Then the malaria parasite became increasingly resistant to antimalarial drugs that were once effective in treating the disease on the continent, and the death rate there spiked yet again. "It was more apparent than ever to people in [malaria] research that we needed something other than drugs," Heppner says. "A vaccine has always been the most cost-effective and permanent solution to these kinds of challenges."

Not everyone shares that view. Heppner's critics say that vaccine researchers have sometimes squandered government and philanthropic funding on a quixotic dream, when money could be put to better use on more established interventions for reducing malaria, such as drug treatments and insecticide-treated bed nets. But results from a trial of the vaccine RTS,S -- which was tested on more than 2,000 children in Mozambique after the Army helped to develop it with GlaxoSmithKline -- has generated cautious optimism that "a vaccine with reasonable rates of protection against infection and disease is close," as Heppner says.

"Reasonable rates" does not mean anything approaching 100 percent, as a polio vaccine offers, or even the 80 percent and upward that is Heppner's long-term goal. Throughout the 18-month Mozambique trial, the RTS,S vaccine protected about 49 percent of its 1-to-4-year-old subjects against severe disease and about 35 percent against malaria infection. Even those modest rates of protection are unprecedented in clinical trials, with the potential to cut Africa's annual death rate by malaria in half if the vaccine were widely distributed. That is reason for everyone involved to believe that the vaccine will be ready for mass pediatric use by 2011, after the last stages of trials are complete. For now, in those vast parts of Africa untouched by clinical trials, the outlook for the stricken is as grim as ever.

ON A SATURDAY MORNING IN AUGUST, Heppner is in Kenya. He has come to a town in the western part of the country called Kisumu, where Walter Reed has a facility for conducting malaria research and clinical trials of prospective vaccines and drugs. He stays at the Imperial Hotel, a place that Westerners like in no small part because of its in-room amenities, which include a light pesticide spraying around the walls and mosquito nets for the beds. Opposite him at breakfast that morning are two monied tourists, one American, the other Canadian, both of them serene because they are on a highly effective antimalarial drug called Malarone. That's the prudent move, Heppner tells them, because there is no area in the world with a higher rate of malaria transmission than western Kenya, especially balmy Kisumu, much of which sits on the beautiful and hippo-populated Lake Victoria, a mosquito haven. Heppner doesn't take an antimalarial. He figures if he contracts the disease, the symptoms won't hit him until he gets home, where he can be treated at Walter Reed.

Still, watching Westerners here who have the good drugs always reminds him of the capriciousness of health care in a sub-Saharan country such as Kenya, where 30,000 children die annually from malaria. Somebody can afford a good antimalarial pill and lives; somebody else can't and maybe dies. Today, he's traveling with a group to Siaya, a town and governmental district, where about 22 percent of children perish from disease before they reach age 5. Siaya District has 510,000 residents, and last year more than one-third of them were stricken by malaria, according to district health statistics. Siaya is about a 90-minute drive northwest of Kisumu, toward the Ugandan border, on a paved two-lane, rural highway that has a colloquial name that sounds like something out of a Bogart film -- The Road to Busia.

Along the shoulder of the road on the way to Siaya, there are small boys herding goats and cows, which obediently lumber single file up the road. Young men try to repair the caved tin roof and gaping holes of another mud-and-thatch abode, which is home to human and mosquito alike. Women with strong, straight backs lug babies and traverse uphill with huge loads balanced atop their heads. Public transport in the way of small buses is often beyond the walkers' economic reach. In some spots, the nearest hospital is 30 kilometers away.

The vehicle bearing Heppner and a group of others from the Walter Reed Kenyan unit stops at Siaya District Hospital. Heppner and his colleagues have come to receive an update on the care burden posed in Siaya by malaria. It is an informal briefing, some of it delivered in an office, the rest in a hospital yard, where a rooster is crowing nearby and a doctor is having a $47 water pump installed -- "The most important $47 we're going to spend all day here," the doctor tells Heppner -- to get rid of standing water attracting mosquitoes.

A light rain has stopped, replaced by a faint rainbow, a blue sky the color of a robin's egg and a tropical breeze carrying a fragrance that smells like jasmine. The glory of the African morning makes what is happening on the other side of the walls only more incongruous. The doctors report that malaria now accounts for more than 70 percent of their patients. Ten to 20 malaria cases require hospitalization daily there, and, as is the case across the Siaya District and all of Africa, the disease is the biggest killer of children at the hospital: 15 die there of malaria in an average month. There are days with so many malaria-stricken children in the emergency section that the tiny victims must be placed six at a time across an examination table meant for one.

Segueing to a more hopeful subject, the Siaya doctors mention a district project just completed: the distribution of free insecticide-treated bed nets to families with young children. "We think this intervention could be very promising," a doctor says.

Heppner smiles neutrally. He sees all kinds of complications with bed nets: Sometimes they're not hung correctly; sometimes there are holes in roofs that make them useless; and they can't protect children who are playing outside at dusk, when mosquitoes start feeding. "Well, you're doing great work," Heppner says.