Researchers are looking for volunteers to participate in a COVID-19 study that aims to further understand the body's immune system response to the virus and investigate whether antibodies offer any type of long-term immunity.

When a person gets sick, antibodies are created by the body's immune system to block the virus from being able to infect new cells. Some of these antibodies can remain in the body for a long time and, for some diseases, the presence of long-term antibodies offers protection or immunity.

It's unclear whether the presence of long-term antibodies against the coronavirus offers any type of immunity or protects people from being reinfected, according to Translational Genomics Research Institute scientist John Altin, who is leading the study.

But dozens of tests to detect antibodies in a person's blood have hit the market nationwide and there is hope that this type of testing could be used to clear people to return to work and begin to reopen the economy. These tests have varying degrees of accuracy and many haven't been reviewed by the FDA.

"New antibody tests are coming out pretty much every day," Altin said. "Even for the ones that perform very well ... it's not clear what having an antibody response means in terms of longer term protection."

Antibody tests typically only test for two types of antibodies that react to spike structures on the outside of the virus. These spikes have been targeted by many researchers because the spikes are what the virus uses to bind to and infect cells.

In contrast, the study by TGen will look at different antibodies that interact with many parts of the virus, not just the spikes. This could have crucial implications for how physicians treat the new coronavirus.

There are no proven treatments for COVID-19, but a growing number of experimental treatments involve taking plasma from recovered COVID-19 patients and injecting it into people currently suffering from the disease. The rationale behind this type of treatment is that plasma from recovered patients contains antibodies that can help others fight the disease.

"Not all antibodies are created equal," Altin said. "It's well known that antibodies can basically cure this disease ... but there are some indications that the wrong kind of antibodies could exacerbate the disease."

It's not clear yet how big of a problem bad antibodies are for COVID-19, but Altin said one example of a detrimental antibody response can be found in Dengue fever, a mosquito-born disease that causes muscle and joint pain, severe bleeding and even death. For Dengue fever, antibodies from a person's first infection actually help the virus re-infect cells in the future and can make second infections more severe and life-threatening.

As a result of the bad antibodies, "there were some vaccines that ended up causing probably more harm than good," Altin said.

By doing a more robust study of antibodies, TGen hopes to find the right protective antibodies that could be used for eventual therapies or vaccine development. This refined approach could also isolate antibodies to be manufactured as a treatment, rather than relying on donated plasma.

Manufactured treatments take more time to develop and get regulatory approval, according to Altin, whereas experimental plasma treatments can be implemented directly to patients faster.

How the study will work

TGen is partnering with City of Hope, a nonprofit clinical research center in California for this study. City of Hope is currently recruiting recovered COVID-19 patients to donate plasma as an experimental treatment forcurrent cases.

TGen will study each sample donated to create a robust profile of the antibodies present. Then the two nonprofit institutes will analyze how different types of antibodies present in the plasma may have changed the clinical outcome.

"We're trying to understand the science behind clinical work," Altin said.

By doing this, researchers hope to determine which antibodies correspond to good treatment outcomes and figure out who the best donors of plasma would be in the future.

TGen is also actively recruiting volunteers for another part of the study, which will measure antibodies in a person's blood over time and see what types of antibodies are present in the blood of recovered patients. They hope to recruit at least several hundred participants nationwide.

Study participants will be asked to complete a short online health questionnaire and will then receive a blood sample collection kit. Participants would prick their fingers and put a drop of their blood on a collection card. One week later, they would repeat the process, add the second drop of blood to the collection card and return it by mail to TGen.

"The purpose is...to look at how antibody response changes over time," Altin said. "We're initially starting simple so we're just going to get two spots one week apart from everybody ... We may in future versions of the study extend that."

One benefit of this type of citizen-science study is that the test can be done entirely within people's homes, without putting participants at risk. A shortcoming is that participants could incorrectly or inconsistently collect blood samples in a way that affects test results.

The study is funded by a grant from the California Institute of Regenerative Medicine. Recruiting enough volunteers for the study could take a few months, according to Altin. Once the study is underway, he said it would take another month or two for researchers to finish their data analysis of those samples.

To sign up for the study, participants of the study must be U.S. residents, be 18 or older, and must have tested positive for COVID-19 and then recovered.

Amanda Morris covers all things bioscience, which includes health care, technology, new research and the environment. Send her tips, story ideas, or dog memes at amorris@gannett.com and follow her on Twitter @amandamomorris for the latest bioscience updates.

Independent coverage of bioscience in Arizona is supported by a grant from the Flinn Foundation.

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