Emerging infectious disease laboratory and diagnostic preparedness to accelerate vaccine development

Roberts, Christine C.

The Coalition for Epidemic Preparedness Innovations (CEPI) and others are working to ensure that rapid response mechanisms are in place to address emerging infectious diseases. 24, 61, 62 The CEPI coalition was launched in 2017 as an innovative concept to establish global partnerships between public, private, philanthropic and civic organizations with the goal of accelerating the development of vaccines against emerging infectious diseases and strengthening vaccine access capabilities before an outbreak situation is encountered. Funding to support development teams building the infrastructure necessary for rapid vaccine design, manufacture, and clinical assessment is being provided to help ensure that we are prepared for EID outbreaks that may occur. 62 EID public health and countermeasure programs have unique challenges for diagnostic and vaccine clinical assay development purposes. 2, 39, 41, [63] [64] [65] [66] [67] [68] [69] [70] [71] There may be an incomplete understanding of the biology or epidemiology of a new pathogen, which can delay or confound the selection of a relevant vaccine target and the subsequent assay development to be used to evaluate the candidates. The field may suffer from a lack of available reagent sources or with inconsistency in quantity and quality of those available, especially early in the discovery and development process. The difficulty in obtaining or developing relevant human sample panels, reference materials and/or international standards for the evaluation of test methods add to the challenges to support assay performance from early vaccine development through licensure. 10 Although the speed at which the EID diagnostic or vaccine development field needs to move will be dependent upon the urgency of the pathogen outbreak and its impact on human life, scientific and quality principles must still apply when developing vaccine or diagnostic assays. Biological assay standardization is critical. 2, 10, 17, 71, 72 At a minimum, the development of relevant biological assays with adequate sensitivity and specificity for the application should use biostatistics to establish and verify assay performance and to maintain the ability to produce stable and reproducible results over time to support diagnostic or vaccine program needs. The criteria for acceptability of any given test system will be dependent upon the nature of the pathogen, our understanding of the immunology to fight the pathogen (both of which may be poorly understood in an EID situation) and the assay platform. If assay performance consistency and quality are not demonstrated, the validity of clinical study results may be questioned. In the execution of vaccine clinical trials, assay methodology must be accurate, specific and robust with highquality procedures in place for sample collection, processing, and storage to ensure success. 25, 26, 36, 37 The translatability of assay methodology is also important if the acceleration of vaccine development is dependent upon the use of animal challenge studies to establish efficacy or to help define a correlate of protection for an EID pathogen.