RTSS adjuvanted with AS01(London School of Hygiene and Tropical Medicine)

Over the last two decades, a significant reduction has been seen in malaria-attributable morbidity and mortality but still, it remains a major public health burden in many countries. The outbreak of malaria due to climate change in some countries emphasizes the critical need for improved strategies to treat, prevent, and control malaria. Although WHO has recommended RTS, S/AS01, and R-21/Matrix-M (R21), these vaccines have shown lesser efficacy. The low efficacy of the vaccines emphasizes the need for discovering a promising vaccine. Present vaccines are parasite-based and can only reduce the severity of the disease and risk of death. Transmission-blocking vaccines (TBVs) can prevent the risk of the spread of infectious malaria disease worldwide. Several studies revealed that mosquito-based TBVs can effectively target a wide variety of parasites, and significantly reduce the survival rate of the vector. In the present review, various mosquito-based studies involving antisera-raising methods for evaluating transmission-blocking efficacy are included. This review focuses on the efforts made to justify a specific protein as a TBV candidate, the status of mosquito-based TBV antigens, challenges in developing potential mosquito-based TBV, and promising approaches for improving the transmission-blocking efficacy of the TBVs. This review gives an insight into the benefits of using mosquito-based TBVs as a transmission-blocking strategy for malaria.

Malaria vaccines are crucial for advancing public health and achieving malaria elimination. Currently, pre-erythrocytic vaccines like RTS, S/AS01 and R21/Matrix-M are in use, but their effectiveness is limited. Ongoing research on blood-stage vaccine candidates such as RH5, MSP1 and MSP3 has shown promising results. Incorporating a blood-stage vaccine could greatly enhance malaria control by targeting the symptomatic phase of the infection, providing additional protection alongside pre-erythrocytic vaccines and other control methods. Understanding the structural biology and immunological interactions of blood-stage antigens is essential for developing effective vaccines. Combining pre-erythrocytic and erythrocytic-stage vaccines could lead to better protection, improved public health outcomes and significant progress toward malaria elimination.