Hundreds of YNHH health care staff, COVID-19 patients given antibody tests

Researchers hope the tests will answer questions about the nature of the global pandemic, such as whether people exposed to the virus are immune to reinfection.
Collage of blood samples and Yale New Haven Hospital entrance.

(Image credit: Kristin Hynes/

Healthcare workers and COVID-19 patients at Yale New Haven Hospital (YNHH) have begun receiving blood tests designed by Yale scientists to detect antibodies to the virus, yielding information researchers hope will answer important questions about the nature of the global pandemic.

The new serum antibody tests would reveal which healthcare workers were exposed to the virus in the past and might have immunity to re-infections, potentially allowing them to safely work around COVID-19 patients. Giving the test to patients with a confirmed diagnosis of COVID-19 will help establish its accuracy. The new test, intended for research purposes, has not yet been approved for use in the clinic. Data generated by the tests will ultimately help researchers answer various questions presented by the novel coronavirus, the most pressing of which are whether people exposed to the virus are immune to re-infection and whether antibodies against the virus can paradoxically worsen illness.

We want to know what proportion of people were infected and if antibodies protect you from re-infection once you come out of lockdown,” said Yale’s Albert Ko, department chair and professor of epidemiology (microbial diseases) and of medicine (infectious diseases).

Ko and team are also investigating whether antibodies against the SARS-CoV-2 virus can in some cases be harmful by helping trigger the devastating “cytokine storm” immune response that can fill lungs with fluid and shut down major organs, including the heart and kidneys.

Understanding the quality of a patient’s antibody response is therefore very important in giving assurance that a person is immune,” said Aaron Ring, assistant professor of immunobiology. “Also, if harmful antibody responses can be identified, this may suggest new therapeutic strategies for COVID-19.”

The new blood serum test can pick up antibodies generated by the immune system in the days and weeks following infection with COVID-19. However, the lack of antibody tests, and questions about their accuracy, have limited their widespread use. 

While the Food and Drug Administration is expected to approve antibody tests this week, the lack of testing capability prompted a team of Yale researchers headed by Ko, Ring, and members of their clinical and research groups — including YNHH physician Camila Odio, associate research scientist Arnau Casanovas Massana, and bioengineering graduate student Feimei Liu — to get a head start on the process. They have already examined antibody responses to a coronavirus protein in hundreds of patient and healthcare worker samples, and they are now bringing new tests online to check whether antibodies are produced in response to other viral proteins as well. 

One key question they hope to answer is whether antibodies generated by COVID-19 actually prevent re-infection, as they do against strains of flu virus. If so, policymakers may be able to relax social distancing guidelines for those who possess these antibodies, and allow them to re-enter the workforce. However, common cold viruses, for instance, also generate antibodies but they do not protect people from re-exposure.

Not all antibodies are created equal,” Ko said.

The data generated by antibody tests might help guide in the development of vaccines, Ko said.

We need to know what drives protective responses to the virus to help spur vaccine development,” he said.

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Part of the In Focus Collection: Yale responds to COVID-19

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