3rd Global Meeting on Implementing New and Under-utilized Vaccines, 16-18 June 2009
Workgroup 1. Use of local surveillance data to assess impact of new vaccines for advocacy of sustainable financing
Background
A number of surveillance networks for rotavirus, invasive bacterial disease and Japanese encephalitis have been established in the past several years with targeted support from global partners. The transition of surveillance activities from the Pneumo and Rota ADIPs and the Hib Initiative to WHO is now in its final stages: site contracting is nearly complete; identifying and establishing contracts with regional laboratories is under way; surveillance data collection, sharing and reporting has been standardized; and the revision of Standard Operating Procedures, case report forms and databases is ongoing. A layered approach to surveillance has been established: layer 1 is “core” surveillance taking place at hospital sentinel sites (1 per country) for bacterial meningitis and severe diarrhoea, layer 2 is “added surveillance” at additional select sites for invasive bacterial disease (bacteraemic pneumonia/sepsis, 1 site for every 3 countries), and layer 3 is “enhanced population-based surveillance" to determine incidence of IBD and rotavirus diarrhoea (at least 1 site per region). Identification of population based surveillance sites and its incorporation into the WHO-coordinated network is ongoing in most regions. The global surveillance network is country-owned, and coordinated by the WHO Regional Offices with technical support from WHO HQ and partners. Sites included in this network have been providing information for disease burden estimation, evidence-based decision making for vaccine introduction, monitoring circulation of specific serotypes/genotypes and changes in serotype/genotype distribution and antimicrobial susceptibility, and will allow for the evaluation of vaccine impact after vaccine introduction. Surveillance networks will be enhanced further in the coming years and surveillance targeting newer vaccines such as HPV will be implemented, and when possible, integrated with existing surveillance networks. Advocating for sustained vaccine use after introduction and for continued vaccine funding will be critical at the country level, and surveillance data are expected to play a major role in supporting such advocacy.
Main Topics of Discussion
- Available rotavirus, invasive bacterial diseases and Japanese encephalitis surveillance data was reviewed and country experiences on using surveillance data to inform their decision-making on vaccine introduction were discussed.
- Surveillance data are vital for making decisions on vaccine introduction.
- Ownership of public health surveillance system by countries/ministries of health is critical for its sustainability.
- Ongoing surveillance following vaccine introduction is needed for multiple reasons, e.g., to identify causes of diarrhoea other than rotavirus, to identify non-vaccine pneumococcal strain types causing disease and monitor serotype replacement, to monitor impact of vaccines, to monitor antimicrobial resistance patterns, and to help identify other prevention activities besides vaccines.
- The use of surveillance data for vaccine impact demonstration and sustained use is needed. Current core surveillance data will need to be further supplemented with sepsis and pneumonia surveillance data, as well as population-based incidence data for both invasive bacterial disease and rotavirus, in order to document the impact of these new vaccines.
- Surveillance data are underestimates of disease and do not describe the full burden of disease, particularly with regards to mortality. It is important to use surveillance data in combination with models, vaccine coverage data, and vaccine effectiveness data to further report on vaccine impact, particularly on death, pneumonia, and mild disease, which are not adequately captured in the surveillance system.
- These additional data needs identified should be fulfilled through special studies.
- Surveillance data will feed into cost effectiveness studies, which results will be important to support advocacy of sustainable financing.
- Uses of data generated by certain epidemiologic studies (e.g., vaccine effectiveness case control studies) require caution, taking into consideration the study design, sample size, etc.
- Surveillance data are critical for advocacy. These data can help identify the successes and gaps that need to be addressed in immunization and disease control programmes.
- Expanding the surveillance network globally and improving its quality is hampered by general lack of human resources at sentinel sites, and lack of qualified, well-trained laboratory staff and epidemiologists. Maintaining and motivating staff, as well as addressing recurrent training needs due to staff turn-over are challenges to surveillance.
Recommendations
- More resources are needed for training and retaining human resources for surveillance - both at the country and the sentinel site levels.
- The importance of surveillance and its data uses at country level should be communicated clearly to decision makers and public health professionals. It should be reinforced that sentinel surveillance for rotavirus and invasive bacterial diseases is not research, but rather part of ongoing sentinel surveillance activities which are set up differently from other routine vaccine preventable diseases surveillance systems.
- Interpretation of available surveillance data should take into consideration its limitations. These limitations should be adequately communicated to decision makers and public health professionals.
- Surveillance data quality needs to be improved.
- Further standardization across the surveillance network including standardizing case definitions for invasive bacterial disease should be sought.
- Surveillance data gaps should be filled by expanding surveillance networks to incorporate population-based sites.
- Special studies such as case-control vaccine effectiveness studies, vaccine probe studies, vaccine impact studies to assess mortality reduction, should be conducted in centers of excellence and will provide data which will complement routine sentinel based surveillance data.
- The importance of surveillance for new and underutilized vaccine preventable diseases should be discussed with different groups, making sure they understand both the strengths and limitations of the data and highlighting how surveillance is different from “research studies”.
- Public health professionals and scientists need to be trained on how to package and report surveillance data in an optimal way for advocacy.
- Vaccine advocacy needs to include advocacy for funding for improved surveillance for new vaccines.