Preclinical evaluations of Pfs25-EPA and Pfs230D1-EPA in AS01 for a vaccine to reduce malaria transmission

Kelly M Rausch; Emma K Barnafo; Lynn E Lambert; Olga Muratova; J Patrick Gorres; Charles Anderson; David L Narum; Yimin Wu; Robert D Morrison; Irfan Zaidi; Patrick E Duffy

doi:10.1016/j.isci.2023.107192

Preclinical evaluations of Pfs25-EPA and Pfs230D1-EPA in AS01 for a vaccine to reduce malaria transmission

iScience. 2023 Jun 22;26(7):107192. doi: 10.1016/j.isci.2023.107192. eCollection 2023 Jul 21.

Affiliation

¹ Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.

Abstract

Malaria transmission-blocking vaccine candidates Pfs25-EPA and Pfs230D1-EPA target sexual stage development of Plasmodium falciparum parasites in the mosquito host, thereby reducing mosquito infectivity. When formulated on Alhydrogel, Pfs25-EPA has demonstrated safety and immunogenicity in a phase 1 field trial, while Pfs230D1-EPA has shown superior activity to Pfs25-EPA in a phase 1 US trial and has entered phase 2 field trials. Development continues to enhance immunogenicity of these candidates toward producing a vaccine to reduce malaria transmission (VRMT) with both pre-erythrocytic (i.e., anti-infection) and transmission-blocking components. GSK Adjuvant Systems have demonstrated successful potency in pre-erythrocytic vaccine trials and might offer a common platform for VRMT development. Here, we describe preclinical evaluations of Pfs25-EPA and Pfs230D1-EPA nanoparticles with GSK platforms. Formulations were stable after a series of assessments and induced superior antibody titers and functional activity in CD-1 mice, compared to Alhydrogel formulations of the same antigens.

Keywords: Molecular biology; Parasitology.