The Power of Malaria Vaccine Trials Using Controlled Human Malaria Infection.

Controlled human malaria infection (CHMI) in healthy human volunteers is an important and powerful tool in clinical malaria vaccine development. However, power calculations are essential to obtain meaningful estimates of protective efficacy, while minimizing the risk of adverse events. To optimize p...

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Main Authors: Luc E Coffeng, Cornelus C Hermsen, Robert W Sauerwein, Sake J de Vlas
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2017-01-01
Series:PLoS Computational Biology
Online Access:http://europepmc.org/articles/PMC5230743?pdf=render
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author Luc E Coffeng
Cornelus C Hermsen
Robert W Sauerwein
Sake J de Vlas
author_facet Luc E Coffeng
Cornelus C Hermsen
Robert W Sauerwein
Sake J de Vlas
author_sort Luc E Coffeng
collection DOAJ
description Controlled human malaria infection (CHMI) in healthy human volunteers is an important and powerful tool in clinical malaria vaccine development. However, power calculations are essential to obtain meaningful estimates of protective efficacy, while minimizing the risk of adverse events. To optimize power calculations for CHMI-based malaria vaccine trials, we developed a novel non-linear statistical model for parasite kinetics as measured by qPCR, using data from mosquito-based CHMI experiments in 57 individuals. We robustly account for important sources of variation between and within individuals using a Bayesian framework. Study power is most dependent on the number of individuals in each treatment arm; inter-individual variation in vaccine efficacy and the number of blood samples taken per day matter relatively little. Due to high inter-individual variation in the number of first-generation parasites, hepatic vaccine trials required significantly more study subjects than erythrocytic vaccine trials. We provide power calculations for hypothetical malaria vaccine trials of various designs and conclude that so far, power calculations have been overly optimistic. We further illustrate how upcoming techniques like needle-injected CHMI may reduce required sample sizes.
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spelling doaj.art-4128cac6475d4a258cb56bbd8a77c0702022-12-22T00:15:44ZengPublic Library of Science (PLoS)PLoS Computational Biology1553-734X1553-73582017-01-01131e100525510.1371/journal.pcbi.1005255The Power of Malaria Vaccine Trials Using Controlled Human Malaria Infection.Luc E CoffengCornelus C HermsenRobert W SauerweinSake J de VlasControlled human malaria infection (CHMI) in healthy human volunteers is an important and powerful tool in clinical malaria vaccine development. However, power calculations are essential to obtain meaningful estimates of protective efficacy, while minimizing the risk of adverse events. To optimize power calculations for CHMI-based malaria vaccine trials, we developed a novel non-linear statistical model for parasite kinetics as measured by qPCR, using data from mosquito-based CHMI experiments in 57 individuals. We robustly account for important sources of variation between and within individuals using a Bayesian framework. Study power is most dependent on the number of individuals in each treatment arm; inter-individual variation in vaccine efficacy and the number of blood samples taken per day matter relatively little. Due to high inter-individual variation in the number of first-generation parasites, hepatic vaccine trials required significantly more study subjects than erythrocytic vaccine trials. We provide power calculations for hypothetical malaria vaccine trials of various designs and conclude that so far, power calculations have been overly optimistic. We further illustrate how upcoming techniques like needle-injected CHMI may reduce required sample sizes.http://europepmc.org/articles/PMC5230743?pdf=render
spellingShingle Luc E Coffeng
Cornelus C Hermsen
Robert W Sauerwein
Sake J de Vlas
The Power of Malaria Vaccine Trials Using Controlled Human Malaria Infection.
PLoS Computational Biology
title The Power of Malaria Vaccine Trials Using Controlled Human Malaria Infection.
title_full The Power of Malaria Vaccine Trials Using Controlled Human Malaria Infection.
title_fullStr The Power of Malaria Vaccine Trials Using Controlled Human Malaria Infection.
title_full_unstemmed The Power of Malaria Vaccine Trials Using Controlled Human Malaria Infection.
title_short The Power of Malaria Vaccine Trials Using Controlled Human Malaria Infection.
title_sort power of malaria vaccine trials using controlled human malaria infection
url http://europepmc.org/articles/PMC5230743?pdf=render
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