The Anopheline mosquito midgut-specific alanyl aminopeptidase N (AnAPN1) is a highly conserved luminal midgut surface glycoprotein that is involved in bloodmeal digestion. We have recently shown that antibodies elicited against this antigen can significantly block parasite development in the mosquito and the subsequent cascade of secondary infections once the mosquito takes a bloodmeal from another individual. This type of transmission-blocking vaccine (TBV) is termed "mosquito-based", since it differs from other malaria TBVs which are targeting parasite surface antigens. It has been estimated that more than 1-2 million individuals succumb to Malaria every year, a majority of whom are children under the age of five. Plasmodium parasites, the causative agent of malaria, are transmitted to a vertebrate host by the infective bite of an Anopheles mosquito. Malaria transmission-blocking vaccines (TBVs) are a critical tool for disease elimination. TBVs prevent completion of the developmental lifecycle of malarial parasites within the mosquito vector, effectively blocking subsequent infections. The mosquito midgut protein Anopheline alanyl aminopeptidase N (AnAPN1) is the leading, mosquito-based TBV antigen to date.
[Pictured: Anopheles gambiae membrane feeding on infected blood]