Impact of pneumococcal vaccine on hospital admission with lower respiratory infection in children resident in South Auckland, New Zealand

Aim To assess the change in admission rates for all Lower Respiratory Infection (LRI) including pneumonia for children resident in Counties Manukau District Health Board (CMDHB) with the introduction of the Pneumococcal Conjugate Vaccine 7 valent (PCV7) in June 2008. Method National Minimum dataset ICD10 coded LRI admissions to any NZ hospital August 2001-July 2011 for children <2 year resident in CMDHB were analysed using Poisson regression, omitting 1 August 2008 to 31 July 2009, the first-year post vaccine introduction. Results Pneumonia but not bronchiolitis admissions have been declining since 2001. Pneumonia admissions decreased significantly after PCV7 introduction (incidence risk ratio (IRR) (95% CI) 1.51 (1.08-1.77), additional to the gradual decline since 2001. There was significant decline for Pacific children post PCV7 introduction IRR 1.70(1.39, 2.07) but not for Maori children, IRR 1.05 (0.78-1.40). Maori and Pacific children are at increased risk of admission with LRI compared to European children (relative risk (RR) (95% CI) 4.6 (4.3-5.0) and 5.0(3.7-5.3) respectively) as are those living in Decile 9, 10 compared with those from other deciles, RR 1.43 (1.36-1.50). Conclusion The introduction of PCV7 is associated with reduced admissions for pneumonia in young children yet there has been less impact for Maori in CMDHB.