Katherine M Duszynski1, Nicole L Pratt2, John W Lynch3, Jesia G Berry4, Michael S Gold5. 1. Discipline of Paediatrics, School of Medicine, University of Adelaide, Adelaide, Australia; School of Public Health, University of Adelaide, Adelaide, Australia; Robinson Research Institute, University of Adelaide, South Australia, Australia. Electronic address: katherine.duszynski@adelaide.edu.au. 2. Quality Use of Medicines and Pharmacy Research Centre, Sansom Institute, University of South Australia, Adelaide, Australia. Electronic address: nicole.pratt@unisa.edu.au. 3. School of Public Health, University of Adelaide, Adelaide, Australia. Electronic address: john.lynch@adelaide.edu.au. 4. Discipline of Paediatrics, School of Medicine, University of Adelaide, Adelaide, Australia; School of Public Health, University of Adelaide, Adelaide, Australia; Robinson Research Institute, University of Adelaide, South Australia, Australia. Electronic address: jesia.berry@adelaide.edu.au. 5. Discipline of Paediatrics, School of Medicine, University of Adelaide, Adelaide, Australia; Robinson Research Institute, University of Adelaide, South Australia, Australia. Electronic address: michael.gold@adelaide.edu.au.
Abstract
OBJECTIVE: To determine whether differences in combination DTaP vaccine types at 2, 4 and 6 months of age were associated with mortality (all-cause or non-specific), within 30 days of vaccination. DESIGN: Observational nationwide cohort study. SETTING: Linked population data from the Australian Childhood Immunisation Register and National Death Index. PARTICIPANTS: Australian infants administered a combination trivalent, quadrivalent or hexavalent DTaP vaccine (DTaP types) between January 1999 and December 2010 at 2, 4 and 6 months as part of the primary vaccination series. The study population included 2.9, 2.6, & 2.3 million children in the 2, 4 and 6 month vaccine cohorts, respectively. MAIN OUTCOME MEASURES: Infants were evaluated for the primary outcome of all-cause mortality within 30 days. A secondary outcome was non-specific mortality (unknown cause of death) within 30 days of vaccination. Non-specific mortality was defined as underlying or other cause of death codes, R95 'Sudden infant death syndrome', R96 'Other sudden death, cause unknown', R98 'Unattended death', R99 'Other ill-defined and unspecified cause of mortality' or where no cause of death was recorded. RESULTS: The rate of 30 day all-cause mortality was low and declined from 127.4 to 59.3 deaths per 100,000 person-years between 2 and 6 month cohorts. When compared with trivalent DTaP vaccines, no elevated risk in all-cause or non-specific mortality was seen with any quadrivalent or hexavalent DTaP vaccines, for any cohort. CONCLUSION: Use of routine DTaP combination vaccines with differing disease antigens administered during the first six months of life is not associated with infant mortality.
OBJECTIVE: To determine whether differences in combination DTaP vaccine types at 2, 4 and 6 months of age were associated with mortality (all-cause or non-specific), within 30 days of vaccination. DESIGN: Observational nationwide cohort study. SETTING: Linked population data from the Australian Childhood Immunisation Register and National Death Index. PARTICIPANTS: Australian infants administered a combination trivalent, quadrivalent or hexavalent DTaP vaccine (DTaP types) between January 1999 and December 2010 at 2, 4 and 6 months as part of the primary vaccination series. The study population included 2.9, 2.6, & 2.3 million children in the 2, 4 and 6 month vaccine cohorts, respectively. MAIN OUTCOME MEASURES: Infants were evaluated for the primary outcome of all-cause mortality within 30 days. A secondary outcome was non-specific mortality (unknown cause of death) within 30 days of vaccination. Non-specific mortality was defined as underlying or other cause of death codes, R95 'Sudden infant death syndrome', R96 'Other sudden death, cause unknown', R98 'Unattended death', R99 'Other ill-defined and unspecified cause of mortality' or where no cause of death was recorded. RESULTS: The rate of 30 day all-cause mortality was low and declined from 127.4 to 59.3 deaths per 100,000 person-years between 2 and 6 month cohorts. When compared with trivalent DTaP vaccines, no elevated risk in all-cause or non-specific mortality was seen with any quadrivalent or hexavalent DTaP vaccines, for any cohort. CONCLUSION: Use of routine DTaP combination vaccines with differing disease antigens administered during the first six months of life is not associated with infant mortality.