Katherine L. O' Brien (a), Jennifer Moïsi (a), Sandra Romero-Steiner (b), Patricia Holder (b), George M. Carlone (b), Raymond Reid (a) and Mathuram Santosham (a). Pneumococcal antibodies in a child with type 14 pneumococcal conjugate vaccine failure. Vaccine, Volume 27, Issue 12, 13 March 2009, Pages 1863-1868.

(a) Center for American Indian health, Johns Hopkins Bloomberg School of Public health, 621 N, Washington St., Baltimore, MD, United States

(b) Division of Bacterial Diseases, Centers for disease Control and Prevention, Atlanta, GA, United States

We measured the concentration, opsonic activity, and avidity of serotype-specific serum antibodies in a pneumococcal conjugate vaccine (PnCRM7) efficacy trial participant who contracted serotype 14 pneumococcal bacteremia following dose 3 of PnCRM7. Controls included 18 PnCRM7- and 10 MnCC-vaccinated children without invasive pneumococcal disease (IPD). The child with vaccine failure had 4.98 mcg/mL of serotype 14 antibodies 10 days before disease onset; these antibodies had greater opsonic activity and lower avidity than those of control PnCRM7 recipients. The child had no booster response to a fourth dose of PnCRM7 for most vaccine serotypes. We conclude that antibody concentration, functional activity and avidity do not predict individual protection against IPD, and immunological correlates of protection are only useful at the population level.