5th Global Meeting on Implementing New and Under-utilized Vaccines, 22-24 June 2011
Workgroup 5. Optimizing immunization schedules: an operational perspective
The current global immunization schedule is being technically assessed to determine if it can be modified to better suit the operational needs at country level. Conversely, consideration is being given to determining if any changes can be made in the schedule of the new vaccines being introduced to better align them with the existing vaccination schedules. The technical work is well under way with a focus on pneumococcal vaccine (PCV) and rotavirus vaccines.
Main Topics of Discussion
- Discussion focused on what kind of evidence, and in which format, is critical to consider when attempting to optimize vaccination schedules at regional and country level. PAHO presented an example of how technical information in the Region on vaccination schedules was gathered and shared with countries. PAHO convened an expert group to review evidence on PCV use, and subsequently provided countries with information on vaccination schedules that outlined the different technically viable options.
- Systematic literature reviews of the technical information around PCV introduction were discussed. These reviews are assessing the efficacy and effectiveness of PCV.
- For the introduction of rotavirus vaccine, the age patterns of rotavirus gastroenteritis and actual vaccine schedules are being determined. This will then be assessed to determine the best timing for administration of rotavirus vaccine. A specific format was presented that measures impact as the percent disease reduction, per dose of vaccine. This measurement of impact will also need to take into account delays in vaccination anticipated in routine vaccination programmes, socio-economic differences in risk and vaccine uptake in countries.
- For rotavirus vaccine, the occurrence of adverse events, such as intussusception, and operational aspects of administering the vaccine must be considered. Approximately 80% of children in the developing world are vaccinated via periodic outreach programmes, and these outreach sessions must align with the age for receipt of the vaccine.
- Overall, the work to optimize vaccination schedules is constrained by sparse or missing data from surveillance and other work as related to health outcomes and receipt of vaccination, among other key indicators. Operational issues such as field realities e.g. number of injections given, cold chain capacity, consideration of HIV infected infants and outreach must be considered.
- Once the technical work is completed, the resulting complex technical analysis of information must be clearly presented to decision makers at all levels. WHO's Strategic Group of Experts (SAGE) will provide input into this process over the next year.
- In this context, pilot testing in some countries should be considered as soon as possible, and the broad implications of vaccine schedule decisions for child health should also be considered.
- Present all the information on the WHO website in a clear and synthesized manner that is understandable to NITAGs and physicians, once the appropriate vetting by experts has occurred.
- Develop clear guidelines on schedule recommendations in order to best assist countries in their decision-making process.