Resistance to chloroquine was first noticed in Asia and now exists in eastern and southern Africa where it is spreading westward. Other drugs developed in the 1980s such as melfloquine have suffered the same fate. Despite lack of support by governments and pharmaceutical companies, significant progress has been made over the last 10 years in the development of a malaria vaccine. A limited number of field trials of vaccines are underway in Africa and during the next five years it is hoped that other vaccines will be studied. Investigators have been studying malaria transmission-blocking vaccines.
Malaria parasites have both a sexual and an asexual phase of development.
Dr Thomas Wellems of the Laboratory of Parasitic Diseases has discovered the location of the genes controlling chloroquine resistance in the malaria parasite. Scientists now hope to find out how the genes confer drug resistance and to develop methods of testing for drug-resistant malaria parasites in human blood. Other promising research is seeking to genetically engineer a strain of the anopheline mosquito, which is intractable to malaria parasites. New drugs are also being developed and some are in use, but research into malaria is grossly underfunded. The reason is obvious.