Post-licensure surveillance of vaccine safety comprises of monitoring of adverse events, identification of those events that may be vaccine associated and, where necessary, controlled epidemiological studies to help assess causality. At the Health Protection Agency (HPA) in England a system for performing epidemiological studies using linked hospital episodes and immunisation data was established in the 1990s along with a new statistical approach called the self-controlled case-series (SCCS) for use on datasets which only include individuals with the adverse event of interest. In this thesis by published works I use seven publications from HPA studies addressing a variety of safety concerns to demonstrate the importance of such epidemiological studies and to form a framework which helps address the issues that need considering when doing vaccine safety studies. The seven studies are i) intussusception and oral polio vaccine, ii) measles-mumps rubella (MMR) vaccine and autism, iii) thimerosal in vaccines and neurodevelopment, iv) meningococcal group C conjugate vaccine and purpura/convulsions, v) diphtheria-tetanus-pertussis vaccines and various common and rare events, vi) pandemic influenza vaccine and Guillain-Barré syndrome, and finally vii) MMR vaccine and thrombocytopenic purpura (TP). These studies helped allay safety concerns or, in the case of MMR and TP quantify a true risk. The framework developed covers issues around defining the question, data sources and case-finding, study design and study implementation. In particular issues relevant to the use of the SCCS method are addressed such as ensuring independence of multiple events and bias due to vaccine contraindication. In conclusion the usefulness of epidemiological studies on vaccine safety and of the SCCS method has been demonstrated within a framework that can help with performing future studies.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:582393 |
| Date | January 2013 |
| Creators | Andrews, Nicholas J. |
| Publisher | University of Warwick |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://wrap.warwick.ac.uk/57464/ |
Page generated in 0.0015 seconds