Journal of Vaccine Research 2024, Vol.14, No.2, 85-94 http://medscipublisher.com/index.php/jvr 87 bodies, thereby reducing the adult mosquito population. Another approach is the use of entomopathogenic fungi, which infect and kill mosquitoes (Beier et al., 2008). The integration of biological control methods with ITNs and IRS can enhance the overall effectiveness of malaria control programs. For example, the use of larvivorous fish in combination with ITNs and IRS has been shown to reduce mosquito densities and malaria transmission rates (Beier et al., 2008). Additionally, the use of entomopathogenic fungi can target insecticide-resistant mosquito populations, providing an alternative control measure in areas where chemical insecticides are less effective (Beier et al., 2008). 3.3 Genetic control techniques Genetic control techniques involve the manipulation of mosquito genes to reduce their ability to transmit malaria or to reduce their population size. One such technique is the release of genetically modified mosquitoes that are sterile or have a reduced lifespan. Another approach is the use of gene drive systems, which spread genetic modifications rapidly through mosquito populations (Beier et al., 2008). Recent advances in genetic control techniques have shown promise in reducing malaria transmission. For instance, the release of sterile male mosquitoes has been used to suppress mosquito populations in several pilot studies. Additionally, gene drive systems have been developed to spread genes that confer resistance to malaria parasites or reduce mosquito fertility (Beier et al., 2008). These genetic control techniques can be integrated with ITNs and IRS to provide a comprehensive approach to malaria vector management. In conclusion, advances in vector management, including the combination of ITNs and IRS, biological control methods, and genetic control techniques, offer promising strategies for enhancing malaria control. These approaches can be tailored to local conditions and integrated into national malaria control programs to achieve sustainable reductions in malaria transmission and incidence. 4 Vaccine Development for Malaria 4.1 Types of malaria vaccines Malaria vaccines can be broadly categorized into three types: pre-erythrocytic, blood-stage, and transmission-blocking vaccines. Pre-erythrocytic vaccines target the sporozoite stage of the Plasmodium parasite before it infects liver cells. Blood-stage vaccines aim to prevent the parasite from multiplying within red blood cells, thereby reducing the severity of the disease. Transmission-blocking vaccines are designed to prevent the parasite from being transmitted from humans to mosquitoes, thereby interrupting the cycle of infection (Wilby et al., 2012; Arora et al., 2021; Nadeem et al., 2022). 4.2 RTS,S/AS01 (mosquirix) RTS,S/AS01, also known as Mosquirix, is the most advanced malaria vaccine to date. It is a pre-erythrocytic vaccine that targets the circumsporozoite protein (CSP) of Plasmodium falciparum. The vaccine has undergone extensive clinical trials, demonstrating modest efficacy in preventing clinical malaria in children. In Phase 3 trials, the vaccine showed an efficacy of about 36% in children aged 5-17 months and about 26% in infants aged 6-12 weeks (Wilby et al., 2012; Regules et al., 2016; Arora et al., 2021). Despite its limited efficacy, RTS,S/AS01 has been approved by the World Health Organization (WHO) and is being integrated into routine immunization programs in several African countries (Figure 1) (Mahmoudi and Keshavarz, 2017; Arora et al., 2021; Nadeem et al., 2022). Figure 1 Major events in the progress of RTS,S/AS01 vaccine (Adopted from Arora et al., 2021)
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