Delayed fractional dose regimen of the RTS,S/AS01 malaria vaccine candidate enhances an IgG4 response that inhibits serum opsonophagocytosis.

ABSTRACT: A recent study of the RTS,S malaria vaccine, which is based on the circumsporozoite protein (CSP), demonstrated an increase in efficacy from 50-60% to 80% when using a delayed fractional dose regimen, in which the standard 0-1-2 month immunization schedule was modified to a 0-1-7 month schedule and the third immunization was delivered at 20% of the full dose. Given the role that antibodies can play in RTS,S-induced protection, we sought to determine how the modified regimen alters IgG subclasses and serum opsonophagocytic activity (OPA). Previously, we showed that lower CSP-mediated OPA was associated with protection in an RTS,S study. Here we report that the delayed fractional dose regimen resulted in decreased CSP-mediated OPA and an enhanced CSP-specific IgG4 response. Linear regression

SUBMITTER: Chaudhury S 

PROVIDER: S-EPMC5554171 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature