International researchers last week greeted with cautious optimism news of promising test results in a malaria vaccine trial under way in Mozambique, but malaria experts in Cambodia this week said they were doubtful that any effective vaccine would be ready for use here anytime soon.
A malaria vaccine “and a vaccine for dengue fever would be a godsend here,” said Jon Morgan, executive director of Angkor Hospital for Children in Siem Reap. “But neither is available.”
In the Mozambique study, a vaccine developed by the private US pharmaceutical company GlaxoSmithKline stopped children from contracting malaria about 30 percent of the time and prevented the disease from becoming life-threatening in more than half the cases, according to a report in The New York Times.
While the numbers are not astounding, they are the most promising results obtained yet from an experimental malaria vaccine, doctors and researchers in that news report said.
Developing a malaria vaccine would be difficult in Cambodia, home to several different strains of the disease and a worsening incidence of drug resistance, National Malaria Center Director Dr Duong Socheat said Tuesday. Even if a vaccine were available here, malaria parasites would likely adapt themselves to thwart its effectiveness, he said.
The malaria center will look to other preventative measures before pinning its hopes on a vaccine, he said.
“We think a vaccine is maybe not well-working,” he said. “At the moment, we think asking people to sleep under bed nets is very good protection.”
Previous attempts to test malaria vaccines in this region have stumbled badly. After a Colombian doctor in the mid-1990s claimed to have developed a vaccine that blocked the disease in 77 percent of its South American child test subjects, follow-up tests in Thai refugee camps showed the vaccine to be useless, The Times reported.
A popular myth among Cambodians is that people who have previously had malaria are naturally immune to the disease if they survive, said Dr Sylvia Meek, a lecturer with the London School of Hygiene and Tropical Medicine who was in Cambodia in September to help design a survey for the malaria center.
Though people living in malaria-infested areas can build up a natural immunity to some strains of the disease, “you’re like a baby” in terms of immunity if a person moves away from the area, Meek said.
The young and the very old are particularly vulnerable to the disease, he added.
Finding a vaccine that is effective in children is especially important because their young immune systems are already compromised, Morgan said. About two-thirds of the young patients who visit Angkor Hospital for Children are malnourished, he said.
Without proper nutrition, “you give them any disease, and it’s that much more devastating,” he said.
