Pyrethroid insecticide resistance in Anopheles gambiae sensu stricto is a major concern to malaria vector control programmes. Resistance is mainly due to target-site insensitivity arising from a single point mutation, often referred to as knockdown resistance (kdr). Metabolic-based resistance mechanisms have also been implicated in pyrethroid resistance in East Africa and are currently being investigated in West Africa. Here we report the co-occurrence of both resistance mechanisms in a population of An. gambiae s.s. from Nigeria.
A vaccine to reduce human suffering caused by malarial parasites has been the holy grail of malaria research. Early studies in the 1940’s indicated that attenuated parasites could induce useful immunity. Since that time the genomic revolution led inevitably to the idea of cheap production of safe recombinant vaccines using either expressed protein or DNA vector technologies.
The quest for an effective vaccine as an additional strategy in the control of malaria and to significantly impact the disease burden has progressed tremendously over the past decade and there is a very high probability that that a malaria vaccine will be available for use in the near future. The introduction of any malaria vaccine will be confronted by some cultural issues and it is essential to understand how these factors will ultimately affect its utilization. These and other challenges related to the development and deployment of an effective malaria vaccine especially as they concern endemic countries are discussed.
The RTS,S/AS01E malaria vaccine candidate has recently entered phase 3 testing. Reaching this important milestone is the culmination of more than 20 years of research and development by GlaxoSmithKline and partners and collaborators. The vaccine has been developed to protect young children and infants living in sub-Saharan Africa against clinical and severe disease caused by Plasmodium falciparum infection.
The increasing P. vivax drug resistance and reports of severe and lethal cases, the relapsing parasite behavior and the existence of Plasmodium spp co-infections must prompt more investment and greater efforts for the development of P. vivax vaccine.
Subunit vaccines under development for malaria utilise a limited number of approaches to delivery.
Therefore, along with the efforts to advance the most promising vaccine formulations through the development pipeline, research is taking place into alternative methods for cheaper vaccine production and easy administration. This chapter will discuss some of these approaches, including transgenic plants and mammals as bioreactors for low cost vaccine production and alternative routes of vaccine delivery such as mucosal immunization.
Important progress has been made in the last years especially in sub-Saharan Africa, with the introduction of strategies to prevent malaria in pregnancy consisting of intermittent preventive treatment and insecticide treated nets. However, their coverage is still unacceptably low and malaria continues to demand a huge toll on pregnant women and their newborns. Thus, there is a need to explore other preventive strategies such as a vaccine against malaria, which combined with the current tools would maximise the protection efficacy.
Over the past ten years, EMVI has continually strived to maintain its main goal of accelerating the development of candidate malaria vaccines by facilitating the translational gap between promising experimental malaria vaccines and subsequent clinical trials in Europe and in Africa. By stimulating collaboration, cooperation, networking and joint integrated activities across various fields of research and diseases, and by facilitating the federation of research infrastructures, EMVI is acting today as a catalyst for tomorrow’s vaccines.
The Fulani of west Africa have been shown to be less susceptible to malaria and to mount a stronger immune response to malaria than sympatric ethnic groups. The analysis of HLA diversity is useful for the assessment of the genetic distance between the Fulani and sympatric populations, which represents the necessary theoretical background for the investigation of genetic determinants of susceptibility to malaria.
In conclusion, knowledge of the pharmacokinetic profiles of artemether and lumefantrine is increasing within a range of settings, including infants and children. However, additional data would be warranted to better characterize artemether and lumefantrine pharmacokinetics in patients with hepatic impairment, in pregnant women, and in patients undergoing HIV/AIDS chemotherapy.