Antibody titres and boosting after natural malaria infection in BK-SE36 vaccine responders during a follow-up study in Uganda

Sci Rep. 2016 Oct 5:6:34363. doi: 10.1038/srep34363.

Abstract

The malaria vaccine BK-SE36 is a recombinant protein (SE36) based on the Honduras 1 serine repeat antigen-5 of Plasmodium falciparum, adsorbed to aluminium hydroxide gel. The phase Ib trial in Uganda demonstrated the safety and immunogenicity of BK-SE36. Ancillary analysis in the follow-up study of 6-20 year-old volunteers suggest significant differences in time to first episodes of clinical malaria in vaccinees compared to placebo/control group. Here, we aimed to get further insights into the association of anti-SE36 antibody titres and natural P. falciparum infection. Children who received BK-SE36 and whose antibody titres against SE36 increased by ≥1.92-fold after vaccination were categorised as responders. Most responders did not have or only had a single episode of natural P. falciparum infection. Notably, responders who did not experience infection had relatively high anti-SE36 antibody titres post-second vaccination compared to those who were infected. The anti-SE36 antibody titres of the responders who experienced malaria were boosted after infection and they had lower risk of reinfection. These findings show that anti-SE36 antibody titres induced by BK-SE36 vaccination offered protection against malaria. The vaccine is now being evaluated in a phase Ib trial in children less than 5 years old.

Publication types

  • Clinical Trial, Phase I
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Antibodies, Protozoan* / blood
  • Antibodies, Protozoan* / immunology
  • Antigens, Protozoan / administration & dosage*
  • Antigens, Protozoan / immunology
  • Child
  • Female
  • Humans
  • Immunization, Secondary*
  • Malaria Vaccines / administration & dosage*
  • Malaria Vaccines / immunology
  • Malaria, Falciparum* / blood
  • Malaria, Falciparum* / immunology
  • Malaria, Falciparum* / prevention & control
  • Male
  • Uganda

Substances

  • Antibodies, Protozoan
  • Antigens, Protozoan
  • Malaria Vaccines