Scientists say effective control of COVID-19 depends on universal use of serological standards

Despite the growing volume of data from results of hundreds of COVID-19 serology test kits, experts say the differences among testing platforms mean the data is difficult to compare, limiting the potential to leverage existing data to guide public health decisions. The World Health Organization’ International Standard for SARS-CoV-2 is a tool that can help researchers reporting data in the same units.   

In a Personal View commentary published earlier this year in Lancet Microbe, scientists from the Frederick National Laboratory’s Vaccine, Immunity and Cancer Directorate and international collaborators encouraged their colleagues worldwide to adopt the WHO International Standard, a pool of validated biological material from COVID-19 patient samples that enables comparison of serology data gathered by multiple laboratories. 

“Standardization is key if we want to leverage serology data to inform public health decisions,” said Ligia Pinto, Ph.D., who leads the Vaccine, Immunity and Cancer Directorate. 

Standardized SARS-CoV-2 serology tests generate valuable data 

To conduct serological testing, researchers examine blood samples for the presence of antibodies, proteins produced by the immune system in response to foreign substances, like viruses. Serological testing can be used to monitor exposure to infections and to test the effectiveness of a vaccine response.  

As a result, serology proved an essential tool for public health measures during the pandemic. Early in the pandemic, assays developed by companies worldwide were quickly validated, then made available through the Food and Drug Administration’s Emergency Use Authorization program to enable rapid and widespread testing. Hundreds of antibody tests were developed for SARS-CoV-2. Aggregating test results produces an informative amount of data that can be used to track a pandemic and vaccine responses across the population.  

Non-standardized assays are barrier to data analyses 

However, serological testing data related to SARS-CoV-2 varies worldwide, in part due to an assortment of testing methods and other factors, making it difficult to compare data from different studies. The WHO created the International Standard for SARS-CoV-2, giving researchers testing material as a tool to calibrate their secondary, or national standards to it.  

Following a crush of requests for the International Standard from laboratories using it for purposes other than secondary standards calibration, the WHO standard was depleted in August 2021. It took a year to develop, test and release a second International SARS-CoV-2 Standard. 

Pinto and the FNL team had previously developed the U.S. Human SARS-Cov-2 Serology Standard, calibrated to the International Standard, and made it available to the research community until the second WHO standard was released. The FNL standard has been used by more than 180 laboratories in the U.S. and abroad.  

Declaring critical need for widespread use of standards 

Pinto and team and collaborators from the U.K. Health Security Agency and the U.K. Department of Health and Social Care published their Personal View to spotlight the available standards and their appropriate use, and to share publicly available resources in one place to make standardization easier for serology laboratories worldwide to access. 

“This paper is important and relevant as it summarizes key information related to serology standards, which are critical for testing harmonization efforts and the ability to compare serology data between different studies and vaccines for pandemic pathogens or for any [other] infectious diseases,” Pinto said. 

To Pinto, standardization is essential to serology work and is the foundation for generating reliable data that can be used to inform public health policy. 

“Standardization is what allows harmonization of testing across laboratories and then being able to leverage more data that’s being collected as the data is reported in that same language,” she said. 

Pinto’s team is a leader in the field of serology standardization, with previous experience in HPV serology. The team helps coordinate the NCI Serological Sciences Network for COVID-19 (SeroNet) and has long-standing global partnerships, positioning it to develop standards for existing and emerging diseases as needs arise.