Is the timing of recommended childhood vaccines evidence based?

What evidence is needed to make the most appropriate schedule?

Data from clinical trials represent only a portion of the evidence considered in determining vaccination schedules.5 Burden of disease, immunogenicity, and efficacy studies enable countries to select vaccines and schedules appropriate for their populations, as shown by the recent infographic in The BMJ.6 Vaccine schedules are further refined by considerations such as timing and efficiency of access to the target population to optimise uptake. For childhood vaccines, integration with existing local or national well child visit schedules is a critical consideration. This concept was summarised well in the US Institute of Medicine (IoM) report on the childhood immunisation schedule: “Each new vaccine is approved on the basis of a detailed evaluation of both the vaccine itself and the immunization schedule.” The IoM further stated that randomised controlled trials in which children “would receive less than the full immunization schedule or no vaccines would not be ethical because they would be exposed to a greater risk for the development of diseases and community immunity would be compromised.”5

Once vaccines are in general use local surveillance is generally conducted to evaluate their effect on disease burden. …