Scientific Publications by FDA Staff

J Infect Dis 2010 Jan 15;201(2):214-22

Preterm Infants' T Cell Responses to Inactivated Poliovirus Vaccine.

Klein NP, Gans HA, Sung P, Yasukawa LL, Johnson J, Sarafanov A, Chumakov K, Hansen J, Black S, Dekker CL

Background. The antigen-specific T cell responses of preterm infants to immunization are not well understood. The aim of the present study was to compare the T cell responses of preterm infants after inactivated poliovirus vaccination with those of term infants. Methods. We prospectively enrolled 2-month-old preterm (gestational age, 33 weeks) and term (gestational age, 37 weeks) infants to receive 3 doses of diphtheria-tetanus toxoids-acellular pertussis-hepatitis B virus-inactivated poliovirus vaccine. Whole blood and peripheral blood mononuclear cells (PBMCs) were stimulated with poliovirus vaccine, and memory T cell activation was analyzed by flow cytometry and lymphoproliferation, respectively. Levels of poliovirus neutralizing antibodies were measured in serum. Results. We enrolled 33 preterm and 50 term infants. Preterm infants had fewer circulating CD4(+)CD45RO(+) memory ([Formula: see text]) and CD4(+)CD69(+)IFN-gamma(+) cells activated by staphylococcus enterotoxin B at 2 ([Formula: see text]) and 7 ([Formula: see text]) months of age. After immunization, preterm and term infants had comparable frequencies of poliovirus-specific CD4(+)CD45RO(+)CD69(+)IFN-gamma(+) memory T cells ([Formula: see text]). PBMCs from preterm infants had diminished poliovirus-specific lymphoproliferation ([Formula: see text]). Although all infants developed seroprotective poliovirus antibody titers, serotype 1 titers were lower among preterm infants ([Formula: see text]). Conclusions. Preterm infants develop poliovirus-specific T cell responses that are comparable to those of term infants. However, they demonstrate nonspecific and poliovirus-specific functional T cell limitations, suggesting that investigations into whether T cell differences remain as preterm infants mature are warranted.