Childhood vaccination programs are often presented as one of the main reasons for the historic decline in infectious disease mortality. However, this subject has mainly been investigated in contemporary settings without the long view needed to gain a complete understanding of disease patterns after decades of vaccine use.
Our strategy is to leverage Denmark’s rich historical health and vital statistics data to quantitatively address current population-level questions about childhood vaccination: How do vaccines affect the ecology and impact of epidemic diseases over several decades? Were measles epidemics truly associated with measurable increases in other causes of pediatric mortality? What fraction of the 20th century mortality reduction in European countries can be attributed to vaccines? Why have epidemic diseases such as measles, mumps and pertussis, once well-controlled by vaccines, re-emerged now?