In spite of years of effort, andworldwide investment of billions of dollars, malaria remains a terriblescourge, particularly in Sub-Saharan Africa. Preventive efforts such as treated bed nets and availabilityof safe effective treatment with Artemisinin have somewhat reduced theincidence of clinical disease and mortality. Most recent statistics from the World Health Organization,however, show an annual incidence of 225 million cases and 817,000 deaths,mainly in young African children. For years many experts have recognized that real reductions in incidenceand mortality will require an effective vaccine, but up to now efforts havebeen stymied by the complex life cycle of the malaria parasite. Another factor that increases theurgency for vaccine development is the appearance of resistance to Artemisininin rural areas of Southeast Asia. If that resistance pattern spreads, we will be deprived of the use ourcurrent first line treatment.
Preliminary results of the firstsuccessful large scale vaccine trial have just been released. The RTS.S vaccine shows a 55%protection rate against all malaria episodes in vaccinated African children,and a 35% reduction in cases of severe malaria. Although these results are preliminary, and the success rateis lower that what is achieved currently with vaccines for other diseases,these results are by far the most encouraging ever achieved for a malariavaccine. An excellent New EnglandJournal of Medicine editorial points out that the success of the vaccine willdepend not only on efficacy and safety, but also “on ongoing efforts to makethe vaccine widely available and affordable where it is most needed.”( 2)
Ref:
1. RTS.S. Clinical Trials Partnership: First Results of Phase 3 Trial of RTS,S/ASO1 Malaria Vaccine in African Children. NEJM2011: 1056-65.
2. Rosenbaum,L. A New Tool for MalariaPrevention? A Malaria Vaccine witha Good Shot: NEM 2011blogs.nejm.org.
Submitted by Roger Boe MD.