Malaria is a treatable and preventable disease. However, the disease continues to claim lives, especially of children under-five years of age and pregnant women. According to the World Health Organization’s (WHO) 2012 Malaria report, there were 660,000 malaria deaths worldwide in 2011. The effective control and consequent global elimination of malaria is top priority on the international development agenda. Malaria is associated with poverty because it causes reduced productivity, absenteeism from work and school, and often leads to diversion of limited family resources to treat recurrent episodes, especially in high burden countries in sub-Saharan Africa.
World leaders are committed towards achieving the goal of reducing malaria deaths to near zero by 2015. Health experts have stated that an effective vaccine will be a vital prevention tool to help eliminate malaria. Global research and development efforts for an effective vaccine have been confronted with different challenges – mostly attributable to the complex lifecycle and genetic composition of the parasite. Despite these challenges, there are over 20 vaccine candidates currently under development. The most promising of these vaccine candidates is the RTS,S/ ASO1 vaccine.
The RTS,S/AS01 vaccine is being developed under a product development partnership between GlaxoSmithKline Biologicals and the PATH Malaria Vaccine Initiative (MVI) – with funding from the Bill and Melinda Gates Foundation to MVI. It is targeted to prevent malaria sporozoites from invading the blood and liver cells. It is composed of a malaria antigen derived from the NF 54 strain of Plasmodium falciparum, which is the most deadly of the malaria parasite species, and a potent adjuvant to enhance the immune response.
Encouraging results have been reported from a phase III clinical trial conducted in seven sub-Saharan African countries with 15,460 participants (children). The RTS,S vaccine was found to reduce the risk of experiencing clinical malaria and severe malaria by 56% to 47% respectively in 6,000 children aged 5 – 17 months for 12 months following vaccination. There is ongoing evaluation of the vaccine’s effectiveness in children aged 6-12 weeks, with the vision to incorporate this vaccine into the routine immunization timetable. The complete results from all trial sites are expected by late 2014.
To get more information on other interesting research approaches towards the discovery of an effective malaria vaccine consult the following:
- World Health Organization Rainbow Tables (http://www.who.int/vaccine_research/links/Rainbow/en/index.html)
- Kappe, S., 2011. Seattle BioMed’s Genetically Attenuated Parasite Vaccine (http://www.seattlebiomed.org)
- Agnandji, S. T., Lell, B., Soulanoudjingar, S. et al., 2011. Final Results of Phase 3 Trial of RTS,S/AS01 Malaria vaccine in African Children, New England Journal of Medicine (http://www.nejm.org/doi/full/10.1056/NEJMoa1102287#t=articleTop)
- Szalavitz, M., 2010. Hopes for a New Kind of Malaria vaccine, Time Magazine (http://www.time.com/time/health/article/0,8599,1954177,00.html)