The Coalition for Epidemic Preparedness Innovations (CEPI) established the Centralized Laboratory Network (CLN) in March 2020 in response to the SARS-CoV-2 pandemic. Initially, the network comprised a few high-quality laboratories located in North America, Europe, and Asia (1, 2). CEPI's primary goal was to ensure that all transferred assays to these facilities used the same methods, materials, reference standards, and controls to standardize vaccine evaluation. This approach aimed to streamline and harmonize the assessment of vaccine candidates, enabling more efficient and reliable comparisons between different vaccines under development. During the SARS-CoV-2 pandemic, the CLN played a crucial role by offering free testing of all samples for vaccine developers, regardless of their size, location and funding status (2, 3). This commitment to providing free testing ensured that developers, especially those with limited resources, could access the necessary services to advance their SARS-CoV-2 vaccine candidates. After our significant contribution to controlling the SARS-CoV-2 pandemic, the CLN has expanded significantly, becoming the largest global network conducting global vaccine testing with 17 laboratories from 13 different countries announced so far. To date, five members of the CLN are in Low-and Middle-income Countries (LMICs) including Bangladesh, India, Kenya, Senegal, and Uganda, indicating an expansion in scale and geographical reach into the Global South. This expansion strengthens CEPI-CLN's ability to standardize and accelerate the evaluation of vaccines against epidemic and pandemic diseases. By expanding into the Global South, the CLN reduces sample transfer and testing times, potentially accelerating vaccine development against emerging infectious diseases. In addition, we ensure that vaccine developers in each geographic region have access to the same level of resources. CEPI-CLN is poised to continue its vital role in accelerating the development of vaccines against emerging infectious diseases. Our network currently standardizes the assessment of vaccine efficacy against rare but potential diseases including Lassa, Nipah, Monkeypox, Sudan, Marburg, MERS, and others, ensuring uniformity and accelerating standardized assays for vaccines.

To date, thousands of SARS-CoV-2 samples from many vaccine developers have been tested within the CEPI-Centralized Laboratory Network. To convert data from each clinical assay to international standard units, the WHO international standard and the CEPI standard generated by the Medicines and Healthcare products Regulatory Agency were run in multiple facilities to determine the conversion factor for each assay. Reporting results in international units advances global understanding of SARS-CoV-2 immunity and vaccine efficacy, enhancing the quality, reliability, and utility of clinical assay data.

Background: An effective vaccine against Nipah virus (NiV) is crucial due to its high fatality rate and recurrent outbreaks in South and Southeast Asia. Vaccine development is challenged by the lack of validated accessible neutralization assays, as virus culture requires BSL-4 facilities, restricting implementation in resource-limited settings. To address this, we standardized and validated a pseudotyped virus neutralization assay (PNA) for assessing NiV-neutralizing antibodies in BSL-2 laboratories. Methods: The NiV-PNA was validated following international regulatory standards, using a replication-defective recombinant Vesicular stomatitis virus (rVSV) backbone dependent pseudotyped virus. Assessments included sensitivity, specificity, dilutional linearity, relative accuracy, precision, and robustness. The assay was calibrated using the WHO International Standard for anti-NiV antibodies and characterized reference sera to ensure reliable performance. Findings: Preliminary evaluation of the developed NiV-PNA showed 100% sensitivity and specificity across 10 serum samples (5 positive, 5 negative), with a positive correlation to a calibrated reference assay (R² = 0.8461). Dilutional linearity (R² = 0.9940) and accuracy (98.18%) were confirmed across the analytical titer range of 11-1728 IU/mL. The assay also exhibited high precision, with intra-assay and intermediate precision geometric coefficients of variation of 6.66% and 15.63%, respectively. Robustness testing demonstrated minimal variation across different pseudotyped virus lots, incubation times, and cell counts. Conclusions: The validated NiV-PNA is a reproducible and scalable assay platform for quantifying NiV neutralizing antibodies, offering a safer alternative to virus culture. Its validation and integration into the CEPI Centralized Laboratory Network will enhance global capacity for vaccine evaluation and outbreak preparedness.

The CEPI Centralized Laboratory Network implemented key steps in the transfer and monitoring of the developed immunological SARS-CoV-2 assays to ensure standardization across all the facilities of the network. This comprehensive evaluation reinforces the reliability of the generated data and establishes a solid foundation for a standardized approach, enabling precise inter-laboratory comparisons and contributing to the overall integrity of our network’s clinical results. Herein, we will provide a brief elaboration on the specific measures and procedures implemented to standardize the transfer of assays across our network.