GENALYTE, BLOOD BANK TEAMING UP FOR TESTING
Effort aims to find COVID-19 survivors whose antibodies may help treatment
A partnership announced Thursday between the San Diego Blood Bank and Genalyte, a local health care diagnostics company, will enable thousands of San Diegans to get antibody testing for the novel coronavirus.
People with antibodies to the virus would be prime candidates to donate plasma — an antibody-rich fluid that is being used to treat COVID-19 patients.
Knowing who has antibodies to the virus could also help public officials assess how widely the virus has spread, how deadly it is and how many people may now be protected.
“It aligned so well with our mission and our vision of San Diego Blood Bank,” said CEO David Wellis of the partnership. “Our mission is saving lives with quality blood products and services in partnership with the community.”
Antibody antidotes
In the absence of a vaccine or widely available therapies, antibodies from COVID-19 survivors could be an important stopgap treatment. These immune proteins, which grip the surface of a virus, may block the coronavirus in patients with active infection. Treatments are already under way in San Diego and elsewhere, though, despite encouraging anecdotes, there is still limited data on how well they work.
The blood bank issued a call in mid-april for recovered COVID-19 patients to donate plasma: a pale yellow liquid rich in antibodies and other proteins, obtained by removing red
and white blood cells from blood.
San Diegans answered the call. Wellis said that about 1,800 people have signed up, and these will be the first people invited to get antibody testing. So far, the blood bank has collected plasma from more than 120 COVID-19 survivors. All of that plasma has been sent to hospitals locally and nationwide. Donor plasma can treat between one to three patients, Wellis says, depending on the amount of plasma collected and the donor’s body size.
The blood bank is eager to ramp up its plasma collection program, but it hasn’t had a way to reliably detect whether plasma has antibodies to the coronavirus.
“We don’t do that kind of testing here and were looking for a testing partner,” Wellis said. “When Genalyte came up, we thought, ‘Oh, this is the piece that fits in the puzzle.’”
Promising partnership
Genalyte’s test detects antibodies to viral proteins found on influenza, the virus that causes COVID-19 (SARS-COV-2) and coronaviruses that cause the common cold, according to CEO Cary Gunn. The company, which has a certified laboratory, has been searching for a way to bring its testing to a wider swath of the population.
“We can do 10,000 tests a day,” Gunn said. “We just don’t have people that know how to get 10,000 tests a day to us right now.”
The blood bank will probably perform around 500 blood draws a day initially, Wellis says, though he expects those numbers to ramp up. Those who’ve gone more than 28 days without COVID-19 symptoms can get their blood drawn at any of the blood bank’s centers throughout the county. Those who haven’t had symptoms for 14 to 28 days can go to a collection site at Westfield UTC in La Jolla. All blood draws will be by appointment.
Genalyte says it will get test results back to patients within one to two days. Those with the antibodies would be strong candidates to donate plasma to the blood bank; the blood bank can do 500 plasma collections a day. Positive results will be reported to the county to help local officials track the scope and severity of COVID-19, according to Wellis.
“There just hasn’t been enough testing,” Wellis said. “Death rate, infection rate — all those numbers are not real yet because we just haven’t had the volume of testing available.”
Gunn thinks his company’s test could answer another important question — whether someone has the right kind of antibodies needed for protection. The test measures antibody levels to several parts of SARSCOV-2, including a region on the viral surface known as the receptor-binding domain.
Antibodies that stick to this spot tend to block the virus, known as neutralization, so these antibodies might make someone an ideal plasma donor. But Dennis Burton, an immunologist at Scripps Research Institute, cautions that we don’t yet know the amount of antibody needed to protect patients.
“Nobody knows how much neutralization you need to protect, that’s for sure,” Burton said. “They are f lying blind on that.”
Quality control
Antibody testing has come under fire because of concerns about the accuracy of the hundreds of tests out on the market. Researchers have argued that, in some cases, a large share of positive test results could be false positives — which would mean overestimating immunity and underestimating the virus’ severity.
In light of these concerns, the Food and Drug Administration announced Monday that all commercial test manufacturers must apply for test authorization and provide evidence that their tests meet FDA standards.
Gunn is quick to point out that Genalyte has already taken great pains to validate its test. The company received FDA approval in October for a test that detects antibodies in patients with autoimmune disease. The coronavirus test uses the same type of machine, but for COVID-19.
“If you want something that’s reliable, then you pretty much need to move to a machine, and that’s because the chemistry inside of the machine is very well controlled,” Gunn said, contrasting Genalyte’s approach with the thin testing strips used in other tests.
The company ensures test quality in an unusual way — with algorithms trained to predict whether a sample has antibodies to the coronavirus. Genalyte used blood samples from hundreds of people who had never been infected with the virus as well as San Diegans who’ve recovered from COVID-19 to train these algorithms, and the company says that its test correctly identifies negative samples more than 99 percent of the time.
“This basically makes sense, but the proof is only, ‘Does it work?’” said Roger Bohn, who teaches a course on data analysis at UC San Diego. “Ninety-nine percent is great. Their sample isn’t huge, but that’s about the upper bounds of what we expect.”
Those interested can sign up online at genalytecovid19.com to make a blood draw appointment. Signups are open to everyone, though the aim is to recruit people who had COVID-19 but have been symptomfree for at least 14 days. Testing will cost $149 out of pocket, though that cost will be covered for those with health insurance.
jonathan.wosen @sduniontribune.com