Safety and Immunogenicity of Neonatal Pneumococcal Conjugate Vaccination in Papua New Guinean Children: A Randomised Controlled Trial

Background: Approximately 826,000 children, mostly young infants, die annually from invasive pneumococcal disease. A 6-10-14-week schedule of pneumococcal conjugate vaccine (PCV) is efficacious but neonatal PCV may provide earlier protection and better coverage. We conducted an open randomized controlled trial in Papua New Guinea to compare safety, immunogenicity and priming for memory of 7-valent PCV (PCV7) given in a 0-1-2-month (neonatal) schedule with that of the routine 1-2-3-month (infant) schedule. Methods: We randomized 318 infants at birth to receive PCV7 in the neonatal or infant schedule or no PCV7. All infants received 23-valent pneumococcal polysaccharide vaccine (PPV) at age 9 months. Serotype-specific serum IgG for PCV7 (VT) serotypes and non-VT serotypes 2, 5 and 7F were measured at birth and 2, 3, 4, 9, 10 and 18 months of age. Primary outcomes were geometric mean concentrations (GMCs) and proportions with concentration ≥0.35 µg/ml of VT serotype-specific pneumococcal IgG at age 2 months and one month post-PPV.Results: We enrolled 101, 105 and 106 infants, respectively, into neonatal, infant and control groups. Despite high background levels of maternally derived antibody, both PCV7 groups had higher GMCs than controls at age 2 months for serotypes 4 (p<0.001) and 9V (p<0.05) and at age 3 months for all VTs except 6B. GMCs for serotypes 4, 9V, 18C and 19F were significantly higher (p<0.001) at age 2 months in the neonatal (one month post-dose2 PCV7) than in the infant group (one month post-dose1 PCV7). PPV induced significantly higher VT antibody responses in PCV7-primed than unprimed infants, with neonatal and infant groups equivalent. High VT and non-VT antibody concentrations generally persisted to age 18 months. Conclusions: PCV7 is well-tolerated and immunogenic in PNG neonates and young infants and induces immunologic memory to PPV booster at age 9 months with antibody levels maintained to age 18 months

The association between travel time to health facilities and childhood vaccine coverage in rural Ethiopia. A community based cross sectional study.

BACKGROUND: Few studies have examined associations between access to health care and childhood vaccine coverage in remote communities that lack motorised transport. This study assessed whether travel time to health facilities was associated with childhood vaccine coverage in a remote area of Ethiopia. METHODS: This was a cross-sectional study using data from 775 children aged 12-59 months who participated in a household survey between January -July 2010 in Dabat district, north-western Ethiopia. 208 households were randomly selected from each kebele. All children in a household were eligible for inclusion if they were aged between 12-59 months at the time of data collection. Travel time to vaccine providers was collected using a geographical information system (GIS). The primary outcome was the percentage of children in the study population who were vaccinated with the third infant Pentavalent vaccine ([Diphtheria, Tetanus,-Pertussis Hepatitis B, Haemophilus influenza type b] Penta3) in the five years before the survey. We also assessed effects on BCG, Penta1, Penta2 and Measles vaccines. Analysis was conducted using Poisson regression models with robust standard error estimation and the Wald test. RESULTS: Missing vaccination data ranged from 4.6% (36/775) for BCG to 16.4% (127/775) for Penta3 vaccine. In children with complete vaccination records, BCG vaccine had the highest coverage (97.3% [719/739]), Penta3 coverage was (92.9% [602/648]) and Measles vaccine had the lowest coverage (81.7% [564/690]). Children living ≥60mins from a health post were significantly less likely (adjRR = 0.85 [0.79-0.92] p value < =0.001) to receive Penta3 vaccine compared to children living <30mins from a health post. This effect was not modified by household wealth (p value = 0.240). Travel time also had a highly significant association with BCG (adjRR = 0.95 [0.93-0.98] p value =0.002) and Measles (adjRR = 0.88 [0.79-0.97] p value =0.027) vaccine coverage. CONCLUSIONS: Travel time to vaccine providers in health posts appeared to be a barrier to the delivery of infant vaccines in this remote Ethiopian community. New vaccine delivery strategies are needed for the hardest to reach children in the African region