New Transgenic Sporozoite Vaccination to Completely Eradicate Human Malaria

Image taken from https://www.mdpi.com/2076-393X/3/4/894/htm

Malaria, a human disease caused the Plasmodium parasite, kills almost half a million people around the world. The spread disease has been increasing over the years due to climate change favoring the multiplication of mosquitoes, the carrier of the parasite. Despite the heavy expenditure by governments on public health preventive strategies, malaria continues to spread and kill many people especially in resource limited states. Hence, there is still need for research to find out effective vaccines for prevention of malaria as well as safe and efficacious drugs for treatment.

To develop an effective vaccine, there is need to understand the life cycle of the plasmodium and the pathobiology of the disease. In this manner research studies have found out vaccines which against the early pre-erythrocytic stages of Plasmodium parasites are effective in preventing the disease. Subunit vaccines targeting the circumsporozoite (CS) protein (major surface antigen on sporozoites) has been developed and offer promising results. However, whole sporozoite (WSp) vaccines offer a more pronounced immunity against the early pre-erythrocytic stages of Plasmodium parasites. In a study published by npj Vaccines and titled, ‘A Plasmodium berghei sporozoite-based vaccination platform against human malaria’ Researchers have developed a whole sporozoite vaccine that is safe and more efficacious.

A group of researchers including Miguel Prudêncio of the department of Molecular Medicine in University of Lisboa, Portugal, claim that their WSp malaria vaccine has the potential to wipe out Malaria completely due to its high sterilizing immunity. In making their vaccine, Miguel Prudêncio and co-researchers used transgenic sporozoites of rodent Plasmodium berghei (Pb) parasites as the WSp immunizing agents which act as a platform for expression and delivery of specific immunogens such as PfCS (PbVac). Prudencio et al, then assessed the potential of Pb to elicit cross-species immune responses against Pf by a comprehensive, in silico prediction of CD8+ T cell epitopes in the proteomes of Pf and Pb in human hepatocytes.

The study found out that while the Plasmodium berghei (Pb) infected and fully developed in the human hepatocytes, they did were not able to cause any infection in human red blood cells. The WSp Plasmodium berghei vaccine induced cross-species immunity not only in rabbit and mice but also in human hepatocytes hence implying its effectiveness and great potential to prevent malaria in humans. Based on their findings, researchers have concluded that the Pb vaccines is effective, safe hence need to be considered for further clinical studies.

Read full paper: https://www.nature.com/articles/s41541-018-0068-2

Reference: Mendes A.M, Machado M, Gonçalves-Rosa N, Reuling I.J, Foquet L, Marques C. A Plasmodium berghei sporozoite-based vaccination platform against human malaria. npj Vaccines (2018) 3:33; doi:10.1038/s41541-018-0068-2.

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