In preparation for vaccine introduction in countries of Africa and Asia, activities should be considered to develop capacity for vaccine-pharmacovigilance, to validate the Brighton Collaboration definition for intussusception PF-06463922 in a variety of settings, to establish background rates of intussusception

in select areas, and to conduct case-series studies in early adopter countries (Table 1). Having at least minimal capacity for vaccine safety is an important requirement for countries to make informed decisions about the benefits and risks of vaccination in their populations. Most low- and middle-income countries do not yet have such capacity in place. WHO and partners (regulators, industry, and technical agencies) are currently developing a global vaccine safety blueprint to support countries in reaching such minimal capacity. Some essential elements of that capacity will include an effective spontaneous reporting system for adverse events following immunization (AEFI) and a national advisory body of experts that can review serious AEFI. Having a national group of experts advising the authorities on vaccine safety matters is an important element to ensure not only the quality of the work that will be done with respect to rotavirus vaccines and intussusception but, beyond rotavirus vaccines, for the safe use of all important vaccines of the national immunization programs.

However, due to the low incidence of intussusception, having spontaneous vaccine pharmacovigilance MLN0128 alone will not be sufficient and active surveillance approaches should be developed [6]. Conducting active surveillance for intussusception in resource Tryptophan synthase poor countries will require three main activities to be completed. 1. Assessing the feasibility of using current Brighton Collaboration definition for intussusception in a variety of settings. Having a definition of intussusception that can be applied in many countries according to the patterns of clinical practice is critical to correctly diagnose cases of intussusception

both prior to and after vaccine introduction. While this definition has been prospectively validated in some settings [46], it has yet to be validated in Africa. Case-series studies conducted in Mexico and Brazil using the same protocol produced different results. While an increased risk of intussusception was observed following the first dose of RV1 in Mexico, a similar increased risk was not observed following the first dose in Brazil. One hypothesis to explain this difference in risk is that the take of the vaccine is lower in Brazil because of co-administration of OPV, whereas IPV is used in Mexico. To explore this hypothesis further, additional studies should be undertaken in various setting where both IPV and OPV are used to examine the interaction between rotavirus and polio vaccines.