Project example 13: Pneumococcal vaccine

Project type	Epidemiological analysis
Indication	Invasive disease caused by S. pneumoniae
Intervention	7-valent pneumococcal conjugate vaccine (PCV7)
Methods	Transmission dynamic modeling
Countries	United States of America
Deliverables	Literature review User-friendly diseas transmission model Journal article
Publications	Transmission-dynamic model to capture the indirect effects of infant vaccination with Prevnar (7-valent pneumococcal conjugate vaccine (PCV7)) in older populations. Snedecor SJ, Strutton D, Ciuryla V, Schwartz EJ, Botteman MF. Vaccine 2009; In press.

Given the reduced incidence of pneumococcal disease in older adults observed after initiation of routine infant vaccination, it was apparent that 7-valent pneumococcal conjugate vaccine (PCV7) conferred indirect benefits in addition to direct protection from disease. The aim of this project was to mathematically represent the transmission of bacteria among individuals of all ages in the US population in order to predict the future direct and indirect effects of vaccination in the US. Additionally, the possible benefits in countries yet to initiata a vaccination policy were predicted. We developed a transmission dynamic model parameterized with data from the published literature and US disease surveillance data. The model adequately replicates the observed US incidence of invasive pneumococcal disease in 6 years after PCV7 introduction. The methods and results of our model have been reported in a journal article.