Blood stream infection is associated with altered heptavalent pneumococcal conjugate vaccine immune responses in very low birth weight infants

Sepsis in older children and adults modifies immune system function. We compared serotype-specific antibody responses to heptavalent pneumococcal conjugate vaccine (PCV7) in very low birth weight infants (1500 g,VLBWs) with and without blood stream infection (BSI) during their birth hospitalization.Retrospective analysis of prospectively collected data for the Neonatal Research Network study of PCV7 responses among VLBWs. Infants received PCV7 at 2, 4 and 6 months after birth with blood drawn 4 to 6 weeks after third dose. Serotype antibodies were compared between infants with or without a history of BSI. Regression models were constructed with BW groups and other confounding factors identified in the primary study.In all, 244 infants completed the vaccine series and had serum antibody available; 82 had BSI. After adjustment, BSI was not associated with reduced odds of serum antibody 0.35 μg ml(-1).BSI was not associated with reduced odds of World Health Organization-defined protective PCV7 responses in VLBWs.