Emerging infectious disease laboratory and diagnostic preparedness to accelerate vaccine development

Roberts, Christine C.

In the case of EIDs, it can be difficult to predict what assays will be most useful or informative or will perhaps even provide an immune correlate of protection for a vaccine in early development. Little may be known about the basic virology or immunology of a new pathogen, though the need for developing vaccines and therapeutics is urgent. 9 Some typical methods used as vaccine clinical assays are antibody-binding ELISAs, virus neutralization or bactericidal immunoassays, IFNγ-ELISpot or related cellular immune methodology using the target antigen or antigen-derived peptide pools, and detection of the pathogen through molecular or culture assays. Vaccine clinical assays measuring humoral and cellular immune responses developed early in a program will likely evolve as clinical development progresses or as the scientific knowledge base of the pathogen and relevant immunology broadens. As improvements in technology occur over time, early vaccine assays are often re-designed and bridged to assays with higher throughput, multiplexed detection, reduction of sample volumes, and automation to support testing of large numbers of specimens for late-stage clinical trials. [28] [29] [30] [31] [32] [33] [34] [35] Often, a variety of tests are evaluated early in the program and, based on the usefulness of the data, a down-selection occurs so that the most relevant few remain to support large Phase 3 clinical trials and licensure of the vaccine. 2, 35, 36 Accepted "gold standards" of immunoassays for use at the onset of an EID vaccine program are rare. Critical reagents, standards, and controls must be monitored for consistent sourcing, batch-to-batch variability and overall quality over time. The implementation of partnerships between governmental agencies, academic researchers and industry researchers to help secure these items for the identified priority pathogens before a need should arise is of great importance.