Differences by antigen in seroconversion: sensitivity, specificity and bias in the serological confirmation of pertussis.
Vaccine efficacy of the most efficacious acellular pertussis vaccines in the three recent placebo-controlled clinical trials, when estimated using the primary clinical case criterion, does not change substantially with the inclusion of serological confirmation in addition to culture confirmation. In the Italy trial, because of relatively high anti-PT antibody levels at the time of the acute-phase specimen in episodes of 21 or more days of paroxysmal cough, significant increases in antibody to PT are less likely to be seen in the acellular vaccine groups when evaluating children with bacterial isolation. However, the effect of this decreased sensitivity appears to be compensated by significant antibody increases in the FHA assay. When projecting a maximally sensitive criterion for serological assessment using the observed decreases in IgG antibody to PT over time following primary vaccination stratified by vaccine group, and comparing the expected antibody level with the observed level in the convalescent-phase specimen, the effect on estimated vaccine efficacy is minimal.
Wassilak
S G
SG
Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
Anemona
A
A
Giuliano
M
M
Giammanco
A
A
D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D000942:Antigens, Bacterial / Q000276:immunology; D018849:Controlled Clinical Trials as Topic; D015721:Diphtheria-Tetanus-Pertussis Vaccine / Q000276:immunology; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines; D004797:Enzyme-Linked Immunosorbent Assay / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D015983:Selection Bias; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000706:statistics & numerical data; D014917:Whooping Cough / Q000175:diagnosis* / Q000276:immunology / Q000517:prevention & control
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D015721:Diphtheria-Tetanus-Pertussis Vaccine; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines