Schedules for Pneumococcal Vaccination of Preterm Infants: An RCT.

Background And Objective: Premature infants have a higher risk of invasive pneumococcal disease and are more likely to have lower vaccine responses compared with term infants. Increasingly, immunization schedules are including a reduced, 2-dose, pneumococcal conjugate vaccine priming schedule. Our goal was to assess the immunogenicity of 3 commonly used 13-valent pneumococcal conjugate vaccine (PCV13) priming schedules in premature infants and their response to a 12-month booster dose.

Predictors of immune response and reactogenicity to AS03B-adjuvanted split virion and non-adjuvanted whole virion H1N1 (2009) pandemic influenza vaccines.

In 2009, 943 children aged 6 months to 10 years were randomised to receive two doses of an oil-in water AS03B-adjuvanted split virion or a non-adjuvanted whole virion H1N1 (2009) vaccine. The large numbers allowed investigation of possible predictors of immune response and reactogenicity. We used regression analysis to examine the effect of variables including past receipt of seasonal vaccine, antipyretics post-vaccination, interval between doses and pre-existing antibodies to H1N1 (2009) on immunogenicity.

Birth season and environmental influences on blood leucocyte and lymphocyte subpopulations in rural Gambian infants.

Background: In rural Gambia, birth season predicts infection-related adult mortality, providing evidence that seasonal factors in early life may programme immune development. This study tested whether lymphocyte subpopulations assessed by automated full blood count and flow cytometry in cord blood and at 8, 16 and 52 weeks in rural Gambian infants (N = 138) are affected by birth season (DRY = Jan-Jun, harvest season, few infections; WET = Jul-Dec, hungry season, many infections), birth size or micronutrient status.

Results: Geometric mean cord and postnatal counts were higher in births occurring in the WET season with both season of birth and season of sampling effects.

Aflatoxin exposure in utero causes growth faltering in Gambian infants.

Background: Growth faltering in West African children has previously been associated with dietary exposure to aflatoxins, particularly upon weaning. However, in animal studies in utero exposure to low levels of aflatoxin also results in growth faltering.

Objective: This study investigated the effect of in utero aflatoxin exposure on infant growth in the first year of life in The Gambia.

Effect of month of vaccine administration on antibody responses in The Gambia and Pakistan.

Objective: To explore the relationship between calendar month of administration and antibody (Ab) response to vaccination in subjects from The Gambia and Pakistan, two countries with distinct patterns of seasonality.

Methods: Three cohorts were investigated: Responses to rabies and pneumococcal vaccine were assessed in 472 children (mean age 8 years, males 53%) from rural Gambia. Responses to tetanus, diphtheria and hepatitis B (HBsAg) were investigated in 138 infants also from The Gambia (birth to 52 weeks of age, males 54%).

Early immunological development and mortality from infectious disease in later life.

In rural Gambia the risk of mainly infection-related mortality is 10-fold higher for adults born in the nutritionally-debilitating 'hungry' season, suggesting that immune function may be compromised by events early in life. The current programme of research focuses on the biological mechanisms underlying this hypothesis, exploring early-life environmental influences on immune development and the long-term functional consequences these influences may have. Results obtained to date show that thymus development during infancy is critically sensitive to environmental exposures, with smaller thymuses observed in the hungry season.

Improved thymic function in exclusively breastfed infants is associated with higher interleukin 7 concentrations in their mothers' breast milk.

Background: In rural Gambians, the season of birth strongly predicts adult mortality. Those born during the harvest season have longer life spans than do those born during the hungry season, and the deaths associated with infectious diseases suggest permanent early-life influences on immunity. Thymic measurements showed significantly smaller thymuses in infants born during the hungry season than in those born during the harvest season.