Predictors of pneumococcal conjugate vaccine immunogenicity among infants and toddlers in an American Indian PnCRM7 efficacy trial.

Autor:	O'Brien KL; Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA. klobrien@jhsph.edu, Moisi J, Moulton LH, Madore D, Eick A, Reid R, Weatherholtz R, Millar E, Hu D, Hackell J, Kohberger R, Siber G, Santosham M
Jazyk:	angličtina
Zdroj:	The Journal of infectious diseases [J Infect Dis] 2007 Jul 01; Vol. 196 (1), pp. 104-14. Date of Electronic Publication: 2007 May 24.
DOI:	10.1086/518438
Abstrakt:	Background: Pneumococcal conjugate vaccines are important for the prevention of serious illness and death among infants. Factors associated with pneumococcal conjugate vaccine immunogenicity have not been explored. Methods: Children <24 months of age received 2, 3, or 4 doses of 7-valent pneumococcal conjugate vaccine (PnCRM7) or control vaccine depending on age at enrollment. Serum samples were tested for serotype-specific antibodies by enzyme-linked immunosorbant assay. Multiple linear regression was used to determine predictors of immunogenicity. Results: Among 315 PnCRM7-vaccinated subjects and 295 control subjects enrolled at <7 months of age, geometric mean concentrations (GMCs) of antibodies were significantly higher after dose 3 than after dose 2 for all serotypes except type 4. The proportion of subjects with antibody concentrations > or =5.0 micro g/mL was higher for all serotypes, but the proportion with concentrations > or =0.35 micro g/mL was higher only for types 6B and 23F. Three-dose and 2-dose regimens for those 7-11 and 12-23 months of age, respectively, were highly immunogenic. Increased maternal antibody concentrations were associated with reduced responses to dose 1 and 3 but not to dose 4 of PnCRM7. Conclusions: Maternal antibody is associated with a reduced infant response to PnCRM7 but does not interfere with immune memory. In infants, a third priming dose increases the antibody GMC and the proportion achieving an antibody concentration > or =5.0 micro g/mL but has little impact on the proportion achieving a concentration > or =0.35 micro g/mL.
Databáze:	MEDLINE
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