In the routine childhood immunisation schedule, large numbers of infants are vaccinated with multiple vaccines during their first year of life. It is expected that many adverse drug reactions (ADRs) occurring entirely coincidentally with vaccination will be reported. Primary immunisations are the routine vaccines given to children aged between 2-months and 6-months of age. Due to its peak occurrence around the age of the primary immunisations, sudden death is identified as an outcome of interest for proactive monitoring in young children. This study aims to determine the death rates for all causes of death and sudden infant death syndrome (SIDS) rates following vaccination in a population of infants vaccinated with their primary immunisations in general practice. The results of this study will be used to inform the statistical analyses, which form part of MHRAs proactive vaccine monitoring strategy for when the new routine vaccines are introduced or when there are significant changes in the immunisation schedule.
The objective of this study is to assess all-cause mortality rates, unexplained infant death rates (including sudden infant death syndrome), and sudden infant death syndrome (SIDS) rates in infants following vaccination with routine childhood vaccines according to the UK immunisation schedule. Age-specific mortality rates following vaccination at 8 weeks, 12 weeks, 16 weeks and 12 months of age will be calculated over a period of 11 years stratified by deprivation score and pre-term birth. Currently available data on national rates of infant mortality do not stratify risk to specific enough age bands to be fully robust for use in addressing questions of acute risk. Further, patients receiving vaccinations in the primary care setting will be a subset of the whole population and it is likely that the children at highest risk of early death do not follow the routine vaccination schedule. Hence, using estimates of risk in the whole population will over-estimate the expected background risk in the vaccinated population.
Number of patients with at least one vaccination record for pre-specified vaccines during the study period; a fatal outcome including cause of death and death date. All outcomes will be stratified by age, and where possible, by pre-term birth and deprivation score.
Jenny Wong - Chief Investigator - MHRA
Jenny Wong - Collaborator - MHRA
Katherine Donegan - Collaborator - MHRA
CPRD Mother-Baby Link;ONS Death Registration Data;Practice Level Index of Multiple Deprivation;Pregnancy Register