title: Percentile regression analysis of correlated antibody responses.
abstract: Antibody responses following vaccination usually are analysed by comparing geometric mean concentrations across levels of relevant covariates and by comparing the proportions of vaccinees responding. In the regression setting, the analyses are done on log-transformed concentrations, estimating geometric mean responses conditional on a vector of covariates. More detailed analyses examining the relationship of covariates to different parts of the response distribution may be performed through the application of asymmetric least squares estimation of regression percentiles. We present a method for accounting for correlation in percentile regression analyses of longitudinal antibody response data. We illustrate the procedures with measles antibody response data from Haitian children who participated in a randomized trial of high titre vaccines. The strongest dose and strain effects were seen in the low end of the antibody concentration distributions.
authors.affiliation: Department of International Health, Johns Hopkins University, School of Hygiene and Public Health, Baltimore, MD 21205, USA.
authors.forename: L H
authors.initials: LH
authors.lastname: Moulton
authors.forename: E A
authors.initials: EA
authors.lastname: Holt
authors.forename: J S
authors.initials: JS
authors.lastname: Job
authors.forename: N A
authors.initials: NA
authors.lastname: Halsey
mesh_terms: D000367:Age Factors; D000914:Antibodies, Viral / Q000096:biosynthesis; D000917:Antibody Formation; D004305:Dose-Response Relationship, Drug; D005260:Female; D006205:Haiti; D006801:Humans; D007115:Immunization Schedule; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D008458:Measles Vaccine / Q000008:administration & dosage; D015233:Models, Statistical; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data; D012044:Regression Analysis; D012737:Sex Factors; D013997:Time Factors; D014611:Vaccination
chemical_list: D000914:Antibodies, Viral; D008458:Measles Vaccine