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

Malaria is one of the most dangerous infectious diseases in the world. It occurs in tropical and subtropical regions and affects about 40% of the world´s population. In endemic regions, an estimated 200 million people contract malaria each year. Three-quarters of all global deaths (about 600 per year) are children under 5 years of age. Thus, malaria is one of the most relevant tropical and also childhood diseases in the world. Thanks to various public health measures such as vector control through mosquito nets or the targeted use of insecticides as well as the use of antimalarial prophylaxis drugs, the incidence has already been successfully reduced in recent years. However, to reduce the risk of malaria and to protect children effectively, further measures are necessary. An important part of these measures is an effective vaccination against malaria. However, the history of research shows that the development of an effective malaria vaccine is not an easy undertaking and is associated with some complications. Research into possible vaccines began as early as the 1960s. However, the results achieved were rather sobering and the various vaccines fell short of their expectations. It was not until 2015 that the vaccine RTS,S/AS01 received a positive evaluation from the European Medicines Agency. Since then, the vaccine has been tested in Africa. However, with the COVID-19 pandemic, there are new developments in vaccine research that could also benefit malaria research. These include, among others, the so-called mRNA vaccines. Already in the early 1990s, an immune response triggered by an mRNA vaccine was described for the first time. Since then, mRNA vaccines have been researched and discussed for possible prophylaxis. However, it was not until the COVID-19 pandemic that these vaccines experienced a veritable progress. mRNA vaccines against SARS-CoV-2 were rapidly developed and achieved high efficacy in studies. Based on this success, it is not surprising that companies are also focusing on other diseases and pathogens. Besides viral diseases, such as influenza or AIDS, malaria is high on this list. Many pharmaceutical companies (including the German companies BioNTech and CureVac) have already confirmed that they are researching mRNA vaccines against malaria. However, this is not an easy task. The aim of this article is to describe and discuss possible antigens that could be considered for mRNA vaccination. However, this topic is currently still very speculative.

Malaria is a leading global health problem that was responsible for an estimated 619,000 deaths worldwide in 2021. We modeled the return on investment (ROI) for the introduction and continuation of a four-dose malaria vaccine, RTS,S/AS01, from 2021 to 2030 in twenty sub-Saharan African countries supported by Gavi, the Vaccine Alliance. We used the Decade of Vaccine Economics benefits and costing outputs to calculate an ROI using health impact data modeled by the Swiss Tropical and Public Health Institute (hereafter "Swiss") and Imperial College London (hereafter "Imperial"). The Swiss estimates with a base vaccine price of US$7.00 resulted in an ROI of 0.42, and the Imperial impact estimates with the same base vaccine price resulted in an ROI of 2.30. Inclusion of the fifth seasonal dose for ten countries exhibiting high seasonal disease burden increased the Swiss ROI by 143 percent, to 1.02, and the Imperial ROI by 23.5 percent, to 2.84. To improve ROI, decision makers should continue to improve delivery platforms, decrease vaccine delivery costs, deliver the malaria vaccine in fewer doses, and provide access to vaccine resources.