Immunization, Vaccines and Biologicals

Short and long-term impact evaluation framework on conjugate pneumococcal vaccine (PCV) vaccines

17-19 September 2013, Crowne Plaza Hotel


WHO convened a meeting of technical experts as part of a larger effort to inform decisions and tool development for pneumococcal conjugate vaccine (PCV) impact evaluations. With a large number of countries now routinely using PCV, there is increasing need for guidance on impact evaluations especially for low and middle income countries (LMICs). The existing tools are valuable and are serving an important purpose by providing guidance and advice on best practices, but gaps remain and some need to be adjusted to serve the LMICs needs.

The meeting aimed at addressing key gaps regarding the clinical and epidemiologic design of NP carriage studies to inform PCV impact. WHO coordinates a network of sentinel surveillance sites for invasive bacterial diseases, one of the objectives of which is to establish a platform for assessing the impact of PCV. The New and Underutilized Vaccines and Immunizations (NUVI) sentinel site surveillance includes surveillance for invasive pneumococcal disease. Monitoring the patterns of IPD is an important method for monitoring PCV impact. The NUVI Surveillance program is undergoing a strategic review by an informal Technical Advisory Group (iTAG).

The NUVI Surveillance strategic review with the iTAG and this meeting (i.e. the meeting to provide further guidance on measuring PCV impact) were scheduled during the same week as they are related to each other in content and by an overlap of participants. Other activities towards documenting the potential impact of PCV included development of a PCV impact manual, updating the pneumococcal NP laboratory methods, the PCV immunization schedules evaluation, and the WHO Chest X-ray pneumonia reading methods.

Meeting objectives

  • review and discuss experience using current WHO definition of confirmed X ray pneumonia including the role of conventional radiology versus digital radiology.
  • discuss potential adjustments to the WHO standard method for the radiological diagnosis of pneumonia, both for further vaccine evaluation, disease burden studies, vaccine impact studies and other pneumoniae intervention evaluations.
  • potential mechanisms for organizing a Reference Radiology Group.
  • plans for global oversight for safety/quality of radiology.
  • discuss plans and feasibility to re-read the original reference set of films, its use as a tool to evaluate PCV impact as part of country level efforts; and
  • outline the needs for training of additional research groups and the best approach for training and capacity building.

Expected outcomes

A detailed technical report on updated (if appropriate) WHO standard method for X ray pneumonia, including the global framework for quality assurance, reference reading panel and its uses for PCV impact evaluation will be prepared and published for wide dissemination to all interested parties (both in peer review papers and on the WHO website as an IVB report).