Point-of-care lateral flow immunoassay for diagnosis of pertussis

Pertussis (Whooping cough) is a highly contagious, airborne disease that is rapidly re-emerging as a serious public health threat in the United States. Despite high vaccine coverage, annual reported cases in the U.S. have been increasing recently, with an average of 25,000 per year from 2010-2019. This is a level unseen since the early 1960s. Diagnosis of pertussis is challenging because its early symptoms (during the contagious catarrhal stage, prior to paroxysmal cough) overlap with other respiratory diseases. This is analogous to the diagnostic challenge of COVID-19. The ongoing COVID-19 pandemic has illustrated the critical public health importance of accessible, rapid diagnostics for controlling the spread of highly transmissible respiratory diseases, a category that includes pertussis. Consequently, as with COVID-19, there is a critical need to develop improved pertussis diagnostics to enable prompt, appropriate patient treatment as well as limit needless community transmission. The project goal is a rapid, point-of-care (POC), lateral flow immunoassay (LFIA) to detect Bordetella pertussis antigen from nasopharyngeal specimens. The target population will be symptomatic patients who present in pediatrician offices, urgent care clinics, or small hospital ERs. The product will be a sensitive and specific test that enables immediate action, akin to other highly used and accepted LFIAs (e.g. COVID-19, RSV). This proposal builds on data and results from Phases I and II. First, the B. pertussis protein tracheal colonization factor A (TcfA) was identified as a specific biomarker for presence of the bacterium. Second, a library of epitope- mapped monoclonal antibodies (mAbs) with high affinity and specificity to TcfA was developed. Third, over 784 permutations of mAb combinations were evaluated for construction of a LFIA. Fourth, the prototype LFIA’s configuration was optimized for high specificity and sensitivity for detection of both purified TcfA and clinically relevant concentrations of B. pertussis cells. Fifth, the prototype LFIA showed high sensitivity and specificity for diagnosis of pertussis in a baboon model. Finally, proof-of-concept was demonstrated with patient specimens. Per the original plan, Phase IIb builds on Phases I and II to deliver an FDA-cleared diagnostic. Three aims are proposed. Aim 1 includes an FDA Pre-Submission and transitions from a research-grade, prototype LFIA to a commercial-grade product made under GMP. Aim 2 is a pre-clinical evaluation of precision and reproducibility, limit of detection, analytical specificity and inclusivity, stability, ruggedness, interfering substances, and microbial interference. Aim 3 is a clinical evaluation that will end with a FDA 510(k) Submission. If successful, this study will deliver a pertussis POC test that is easily accessible to all clinics and that provides results in an actionable timeframe – thereby reducing patient morbidity and preventing unnecessary community transmission.