THE PROJECTED IMPACT OF THE PNEUMOCOCCAL CONJUGATE VACCINE IN THE UNITED KINGDOM

K.E. Hvidsten, S. Arikian, V. Ciuryla, P. Conway, R. Casciano, R. Krishnaswamy

Analytica Group, USA., Wyeth-Ayerst Laboratories., Wyeth-Ayerst Laboratories

Streptococcus pneumoniae (SP) is a leading bacterial cause of invasive disease, pneumonia, and acute otitis media (AOM) in the United Kingdom (UK). To address this public health issue, the liscensure of the seven-valent pneumococcal conjugate vaccine (PCV) is expected in the UK in 2001. OBJECTIVE: Perform a disease burden impact analysis of PCV in the UK. METHODS: The expected impact of PCV on the burden of pneumococcal disease in the UK can be determined from the findings of the Kaiser Permanente Efficacy Study and the current epidemiology of the relevant infections in the UK. However, this approach has indicated a significant difference in the reported frequency of these infections between Kaiser and UK-based studies, most notably for non-invasive diseases such as AOM. The AOM incidence rates of several UK and United States (US) studies are compared. The reported incidence of pneumonia in the UK also seems to be limited when compared to the results of the Kasier study. RESULTS: The available incidence rates for non-invasive disease in the UK and the US were used to determine the possible range in the number of pneumococcal disease episodes avoided by PCV vaccination. To include five sources of incidence of AOM and two sources of pneumonia, ten scenarios are presented to estimate the possible outcomes avoided by PCV vaccination. CONCLUSION: The expected impact of PCV vaccination in the UK is difficult to predict due to the probable limitations in the available data on the occurence of non-invasive disease. The representativeness of available epidemiological data must be carefully considered and reasonable assumptions must be made in order to characterize the burden of SP-caused disease.