NEW YORK – A new study by researchers at New York Blood Center (NYBC) found a wide range of antibody levels in recovered COVID-19 patients, suggesting varying levels of immunity to prevent future infections. The study, which is publicly available on preprint server medRxiv and is undergoing peer-review, is the first in the United States to look at antibody levels using commercially available clinical antibody testing platforms and antiviral activity in COVID-19 convalescent plasma donors.

Specifically, NYBC studied seven different COVID19 testing assays measuring antibody levels and the performance characteristics of each test to show a wide range of antibody values from convalescent plasma donors. The study also shows that neutralizing antibody levels, which indicate the ability for antibody to prevent infection, strongly correlated with some antibody tests.  These data will be helpful to estimate the level of immunity in patients and may be critical for interpreting antibody results as early evidence of vaccine efficacy. Thus, the study may help establish a valuable ‘roadmap’ for clinicians to interpret COVID19 antibody tests results.

“New York Blood Center is proud to leverage our expertise in virology, immunology and test and device development to offer major and rapid contributions to the fight against COVID-19,” said Christopher D. Hillyer, MD, President and CEO, of New York Blood Center. “This research has important implications for public policy as we navigate our way through this pandemic. Restarting the economy based on inaccurate serology testing or poorly understood results could have devastating consequences. There is no room for error.”

NYBC maintains the nation’s largest public bank of COVID-19 convalescent plasma, which it accessed for this research. Investigators determined levels of antibodies in convalescent plasma samples and correlated those measurements with neutralization activity, testing whether the antibodies could  block the virus from entering cells. A large proportion of recovered patients had modest antibody levels and higher titer antibody levels correlated well with neutralizing antibody.  Further research is needed to determine the minimum threshold necessary to accurately predict immunity.

In addition to this research, NYBC is also developing two novel SARS-CoV-2 vaccine candidates that are currently in pre-clinical studies and is also investigating biomarkers that may determine individuals at risk for severe disease. To support NYBC’s COVID-19 research, visit our .

COVID-19 RESEARCH REPOSITORY