A Critical Step Forward in MERS Preparedness
In a significant advancement for global health security, a team of South Korean researchers has developed a highly sensitive, rapid antigen diagnostic test (RADT) for Middle East respiratory syndrome coronavirus (MERS-CoV). The novel test, described in a new paper published in Scientific Reports by the Korea Basic Science Institute and Korea Research Institute of Bioscience and Biotechnology, marks the first time time-resolved fluorescence (TRF) has been successfully applied to a lateral flow immunoassay (LFIA) specifically targeting MERS.
MERS, a respiratory disease with a case fatality rate of 36%, remains a World Health Organization (WHO) priority pathogen despite recent declines in reported cases. The lack of a rapid, point-of-care diagnostic test has long been a vulnerability in public health response efforts, particularly in healthcare settings and at borders. This new TRF-LFIA platform could close that critical gap.
Key Findings: 25-Fold Increase in Sensitivity
The newly developed TRF-LFIA demonstrated a detection limit of 0.1 ng/mL for MERS-CoV nucleocapsid (N) protein—25 times more sensitive than conventional cellulose nanobead-based (CNB) LFIA formats. It could detect as few as 5 × 10⁴ copies/mL of MERS-CoV in cultured samples, with high specificity and no cross-reactivity to SARS-CoV, SARS-CoV-2, or influenza viruses.
This performance leap stems from the use of Europium-based fluorescence nanoparticles and an optimized biotin-streptavidin system to orient capture antibodies, significantly improving signal-to-noise ratio and reproducibility. The most effective antibody pair (N6E6-C6D2) provided both high sensitivity and specificity, forming the backbone of the TRF-LFIA strip.
How It Works: From Sample to Result in 20 Minutes
The test functions similarly to a COVID-19 antigen test: users apply a sample to a strip housed in a plastic cassette. The test uses a biotin-labeled capture antibody and Europium-labeled detection antibody that bind to the MERS N protein. This antigen-antibody complex is detected on a test line using a portable TRF reader, which filters out background signals to improve accuracy.
Crucially, the test takes only 20 minutes to deliver results, making it suitable for point-of-care settings, border health stations, and outbreak zones.
Why This Matters for National Security and Public Health
Although overshadowed by the COVID-19 pandemic, MERS-CoV continues to pose a serious threat, particularly in the Middle East and countries with travel ties to affected regions. With a high mortality rate, zoonotic transmission from camels, and no approved vaccines or treatments, rapid identification and isolation of cases are essential.
From a national security perspective, the ability to quickly detect and contain MERS is vital for preventing widespread outbreaks, maintaining trust in healthcare systems, and protecting frontline workers. In global health strategy, scalable and deployable diagnostics are as essential as vaccines and therapeutics.
This technology could also serve as a model for RADT development against other emerging zoonotic viruses, reinforcing pandemic preparedness frameworks.
Next Steps: Validation and Deployment
While the prototype TRF-LFIA has shown excellent laboratory performance, the authors acknowledge the need for further optimization and field validation. Clinical trials with patient-derived samples, stability testing under varying environmental conditions, and cost assessments are essential steps before regulatory approval and wide-scale use.
Nevertheless, this development represents a promising leap forward in rapid diagnostic technology, one with positive implications for outbreak response, epidemiological surveillance, and frontline medical care.
Kim, M.J., Kim, H.-Y., Kim, M. et al. Development of a time-resolved fluorescence-based lateral flow immunoassay for rapid and sensitive diagnosis of Middle East respiratory syndrome. Scientific Reports, 15, 27036. https://doi.org/10.1038/s41598-025-09832-z