A question the state needs to answer to address the continuing concerns around COVID-19 is this: What percentage of the population has been infected with the novel coronavirus SARS-CoV-2? Working on an assumption that infection with the virus confers at least some immunity, knowing how many Arkansans, as a percentage, are at risk should play into public policy in dealing with the pandemic and its aftereffects.
Researchers at the University of Arkansas for Medical Sciences have adapted a test that gives a highly accurate measurement of antibodies to the virus — the blood protein produced to fight infection. The ELISA (enzyme-linked immunoassay) test, as the laboratory element to UAMS College of Public Health’s study of the prevalence of infection in Arkansas, will analyze serum taken from 7,500 Arkansans chosen randomly by the college from now until December.
Like many scientists at UAMS, Karl Boehme, whose research specialty is in reoviruses, and Craig Forrest, who studies gammaherpes viruses, have retooled their research to address the clinical and epidemiological challenges the new coronavirus presents. Unlike quick-result antibody tests in use by such places as blood banks, Boehme and Forrest’s assay — adapted from one developed by colleagues at Mount Sinai Hospital in New York — is a “sandwich” of antibodies, enyzmes and antigens that will provide more than the yes/no answer to the question of infection by SARS CoV-2. UAMS’ more thorough assay will measure both the quality and quantity of COVID-19-specific antibodies. Not only will the results be accurate, Dr. Josh Kennedy, who studies viruses that cause the common cold and is an allergist and immunologist, says it may indicate the most effective convalescent plasma that should be used for transfusion in COVID-19 patients.
By early August, UAMS will be able to use a robotic-assisted immunoassay machine to process as many as 2,500 samples a day. That will allow large samples from places like schools and workplaces to be assessed for past infection.
The Arkansas Department of Health is seeing an active infection rate of between 5 and 15 percent in the last month of testing, and an overall rate of 7.5 percent. The antibody test should broaden the picture of occurrence in the population of the virus, and, assuming that the antibodies convey some measure of immunity, the percentage of the population still vulnerable to SARS-CoV-19. That’s information public health experts need to advise the government on policy to prevent disease spread.
Once a vaccine is developed, the UAMS’ assay can be used to follow vaccinated patients to determine the efficacy of the vaccine and if and when boosters might be required.
As with the flu vaccine, a vaccine would not prevent infection but lessen its effects. As Kennedy put it, “The goal might not be that Frank walking down the street doesn’t get COVID, he might still. But as long as Frank doesn’t end up in the hospital on a ventilator we’ve made a huge difference in Frank’s life.”
The seroprevalence study at the College of Public Health is being led by Dean Mark Williams and Associate Dean Benjamick Amick with epidemiology Department Chair Dr. Wendy Nembhard, Dr. Victor Cardenas, Lori Fischbach and James Selig. Dr. Ericka Olgaard and assistant professor Jeff Moran are overseeing the robotic component. Dr. Jessica Snowden is overseeing pediatric participation. Fred Prior, chair of the department of biomedical informatics, is also a collaborator. The research was supported by\ Arkansas CARES (Coronavirus Aid, Relief and Economic Security Act) federal dollars and the UAMS Translational Research Institute.
The work at UAMS, including the development of the assay and the robotic machine, is a boon to preparedness in Arkansas, Boehme said. “COVID-19 is the fifth major viral emergence in humans of the 21st century,” he said. “Having a lab set up and with equipment, protocols and procedures in place makes us infinitely more prepared to provide similar serologic tests and track the infection when the next viral pandemic shows up … and it will.”