Modelling BCG vaccination in the UK : what is the impact of changing policy?

Bacillus Calmette-Guérin (BCG) remains the only licensed vaccine against Tuberculosis (TB). In 2005, England changed from universal vaccination of school-age children to targeted vaccination of high-risk neonates. Little work has been done to assess the impact of this policy change. This thesis evaluates the impact of this change. Whilst the characteristics of TB in England have been reported elsewhere, little at- tention has been given to the role of BCG. Consequently, I explored and combined, the available data sources. Reporting on data quality issues, trends in incidence rates and differences in outcomes stratified by BCG status. Prior to the change in policy, several studies were carried out to assess the impact. I recreated one such study, correcting a methodological flaw, and found that there was a greater impact than previously thought. Determining the benefits of being BCG vaccinated is necessary to properly assess the impact of the policy change. I evaluated the evidence that vaccination may improve outcomes for TB cases in England and found that there was some evidence of an association between vaccination and reduced mortality. Surveillance data can help assess whether changes in vaccination ... (continues)