Experts study COVID-19 antibodies

Posted at 12:01 AM, Apr 29, 2020
and last updated 2020-04-29 00:01:23-04

TAMPA, Fla.— Healthcare researchers are trying to learn more about antibody testing as tests roll out on the market, including what it could mean for someone’s potential immunity and what it could say about the community.

USF and Tampa General Hospital are among those studying antibodies for the new virus, and how protective and effective they truly are.

“This is a new pathogen so we don’t know when the antibodies come up, if they’re any good, if they’re protective,” said Dr. Kami Kim, the Director of the Division of Infectious Disease & International Medicine at USF.

She’s leading a study looking at viral and blood samples from COVID-19 patients. She said they want to know if antibodies come up in everyone infected with the virus, if the antibodies can protect from future infection and what’s the timing of a positive diagnostic COVID-19 test versus when antibodies come up.

“For those who have the higher antibodies, can we measure 'the good antibodies' and see if there’s any correlation with their titer. So in other words, the level of antibodies and whether they have what we consider our protective properties and that would be useful as far as counseling patients or healthcare workers or first line workers sort of how vulnerable they are,” said Dr. Kim.

It’s one of several research projects ongoing.

“Antibody testing is a very interesting frontier in this pandemic,” said Dr. Seetha Lakshmi, an assistant professor at USF and associate hospital epidemiologist at TGH.

She and a team of researchers started testing about 3,000 healthcare workers this week from USF and TGH who enrolled in a study. Their goal is to better understand what’s happening in the community, whether the antibodies are helpful and what level is needed for them to actually be helpful.

“In an idealistic state we would be finding the right antibodies knowing how much amount is in the blood and knowing that it will protect you. So there multiple layers we need to answer and the scientific community’s working very hard on answering questions right now but we don’t have answers to those questions right now,” Dr. Lakshmi said.

While government officials look at what next phases in the state may be, they’re also looking to use antibody testing.

“If you’re able to do a study about the society as a whole determine what percentage has antibodies that gives us a sense of how a virus has moved through a given community,” said Governor Ron Desantis during a news conference at Tampa General Hospital on Monday.

Florida is anticipating its first shipment of antibody tests in May, and they will be sent out as they are received, according to information from the Florida State Emergency Operations Center joint information center on COVID-19.

“The state is working to secure all available resources to conduct testing efforts across the state, including antibody testing. The department will review FDA approved Emergency Use Authorized manufacturers for antibody testing,” the center said in a statement.
Last week, Miami-Dade County and the University of Miami Miller School of Medicine completed a second round of COVID-19 community testing, examining whether someone had produce antibodies. The study suggested the number of infections is potentially more than 16 times the number of those captured from testing sites and local hospitals.

Hillsborough County leaders received insight on antibody testing during an Emergency Policy Group meeting Monday.

“The problem there is these antibody tests have flooded the market primarily from China and they are not accurate. So it has to be an accurate test, FDA approved done in a pre approved laboratory after it’s been validated. And even with that there are going to be a fair number of false positives, false reassurances because of cross reactivity with what’s called endemic coronaviruses, the common cold coronavirus.” Dr. Charles Lockwood, dean of USF Health Morsani College of Medicine, told EPG members.

So far the FDA has issued emergency use authorizations for at least six companies for an antibody test. It’s also providing more regulatory flexibility.

According to the FDA, it doesn’t plan to object to the development and use of antibody tests that have not been reviewed by the FDA, so long as the test is validated, notification is provided to the FDA and specific information is included, including similar to this list the FDA provided:
* This test has not been reviewed by the FDA.
* Negative results do not rule out SARS-CoV-2 infection, particularly in those who have been in contact with the virus. Follow-up testing with a molecular diagnostic should be considered to rule out infection in these individuals.
* Results from antibody testing should not be used as the sole basis to diagnose or exclude SARS-CoV-2 infection or to inform infection status.
* Positive results may be due to past or present infection with non-SARS-CoV-2 coronavirus strains, such as coronavirus HKU1, NL63, OC43, or 229E.

Last week, the World Health Organization said there is no evidence people who have recovered from COVID-19 and had antibodies were protected from a second infection, in reference to governments considering antibodies as a basis for people to travel or return to work.

But on Tuesday, the tests may have become more available to the general public.

Quest Diagnostics announced the rollout of consumer initiated antibody testing. The companies program allows a patient to request and purchase a test online. A physician will issue an order, if appropriate.

"While the science on COVID-19 is evolving, testing for antibodies may identify people who have likely been exposed to COVID-19 and might have mounted an immune response to the virus.  Our goal is to empower individuals and their physicians to make informed decisions about their risk of infection and of spreading the virus"  said Jay Wohlgemuth, M.D., Senior Vice President and Chief Medical Officer for Quest Diagnostics, in a news release.
But while research carries on in Tampa, experts say more information is needed.

“It’s one dot in making the full picture so we need more dots to connect to make the full picture,” said Dr. Lakshmi.