Vaccine | 2019
Use of different combination diphtheria-tetanus-acellular pertussis vaccines does not increase risk of 30-day infant mortality. A population-based linkage cohort study using administrative data from the Australian Childhood Immunisation Register and the National Death Index.
Abstract
OBJECTIVE\nTo determine whether differences in combination DTaP vaccine types at 2, 4 and 6\u202fmonths of age were associated with mortality (all-cause or non-specific), within 30\u202fdays of vaccination.\n\n\nDESIGN\nObservational nationwide cohort study.\n\n\nSETTING\nLinked population data from the Australian Childhood Immunisation Register and National Death Index.\n\n\nPARTICIPANTS\nAustralian infants administered a combination trivalent, quadrivalent or hexavalent DTaP vaccine (DTaP types) between January 1999 and December 2010 at 2, 4 and 6\u202fmonths as part of the primary vaccination series. The study population included 2.9, 2.6, & 2.3\u202fmillion children in the 2, 4 and 6\u202fmonth vaccine cohorts, respectively.\n\n\nMAIN OUTCOME MEASURES\nInfants were evaluated for the primary outcome of all-cause mortality within 30\u202fdays. A secondary outcome was non-specific mortality (unknown cause of death) within 30\u202fdays 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.\n\n\nRESULTS\nThe rate of 30\u202fday all-cause mortality was low and declined from 127.4 to 59.3 deaths per 100,000 person-years between 2 and 6\u202fmonth 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.\n\n\nCONCLUSION\nUse of routine DTaP combination vaccines with differing disease antigens administered during the first six months of life is not associated with infant mortality.