Public health and economic impact of vaccination with 7-valent pneumococcal vaccine (PCV7) in the context of the annual influenza epidemic and a severe influenza pandemic

A decision-analytic model was constructed to evaluate the impact of 7-valent pneumococcal conjugate vaccine (PCV7) on pneumococcal disease incidence and mortality during a typical influenza season (13/100) and a severe influenza pandemic (30/100). Outcomes were compared for current PCV7 vaccination practices vs. no vaccination. The model was estimated using published sources and includes indirect (herd) protection of non-vaccinated persons.The model predicts that PCV7 vaccination in the US is cost saving for a normal influenza season, reducing pneumococcal-related costs by $1.6 billion. In a severe influenza pandemic, vaccination would save $7.3 billion in costs and prevent 512,000 cases of IPD, 719,000 cases of pneumonia, 62,000 IPD deaths, and 47,000 pneumonia deaths; 84% of deaths are prevented due to indirect (herd) protection in the unvaccinated.PCV7 vaccination is highly effective and cost saving in both normal and severe pandemic influenza seasons. Current infant vaccination practices may prevent >1 million pneumococcal-related deaths in a severe influenza pandemic, primarily due to herd protection.Pandemic influenza outbreaks occurred in the US in 1918, 1957, and 1968, and the World Health Organization declared the novel influenza A (H1N1) virus a pandemic in June 2009. The most notable pandemic occurred in 1918 (H1N1 strain) and caused at least 20 million deaths worldwide, with some estimates as high as 100 million [1-4]. Infection rates (25 - 50% of the population) and deaths (up to 2%) were much higher than is typically observed in an influenza outbreak [5]. A severe influenza pandemic similar to 1918 would have devastating effects in the US and globally, with an estimated 90 million cases of influenza, 1.9 million deaths, 9.9 million hospitalizations, 42 million outpatient visits, and costs of up to $255 billion in the US alone [6].The unprecedented severity of the 1918 influenza pandemic has led to much research, particularly on the high burden of morta