DAVENPORT, Iowa — Local researchers say those who have recovered from COVID-19 develop antibodies, but they may only last for a certain period of time.
At the Mississippi Valley Regional Blood Center Dr. Louis Katz has been studying COVID-19 and it's antibodies.
"They're designed to stick to the bug and make it easier for white cells in the immune system to see it and kill it," Dr. Katz explains. "It's the immune system's attempt to get rid of it."
If a recovered COVID-19 patient wants to donate their plasma through the blood center, they have to show a positive COVID-19 test (a PCR).
"Then we have some sense that what we are sending to the hospitals actually has what we think it has," says Dr. Katz.
Dr. Katz says the sickest patients have the highest antibody count; that's why the blood center asks hospitals to refer their patients to donate.
"These are patients that were very ill and they had to go through that battle," explains Amanda Hess, Director of Donor and Public Relations for the Mississippi Valley Regional Blood Center for the central Illinois community.
"The hospitals know that they were sick, they know their test results, and it makes it very very simple," says Dr. Katz.
But how long do the disease fighting proteins last? Dr. Katz says the antibodies start coasting down two to three months after infection depending on how sick an individual is - it all depends on the person.
"It depends on what antibody you are measuring, depends what test you are using to measure it, depends on how sick you were, depends when you had the infection, lots of different answers to the question," Dr. Katz explains.
Hess says donors should come to the blood center 28 days after they recover from COVID-19. Around 450 recovered COVID-19 patients have donated through all the Mississippi Valley donation centers. Dr. Katz says those donors return every 1 to 2 weeks to make a donation.
"We are starting to see their antibody levels - with the testing we are doing - drifting down at about the 5th or 6th or 7th donation," says Dr. Katz.
Dr. Katz says they haven't asked anyone to leave the COVID-19 plasma program, but that could change in the next months.
"As our supply builds we are going to get more strict and require higher and higher antibody levels," Dr. Katz explains.
He also says there are no documented reinfections yet, but that could change. He continues to recommend people wear masks and social distance. He says half of the positive COVID-19 cases in Scott County appeared in July alone.