Researching a pandemic: Miami-Dade and UM antibody survey switches to a better test
Miami-Dade County’s antibody blood survey that estimated about 165,000 people had been infected by the novel coronavirus has been placed on hold after federal regulations spurred county officials and University of Miami researchers to switch tests.
The change, prompted by an early May update from the Food and Drug Administration, does not invalidate the first three weeks of testing, which extrapolated that about 6.5% of the county population had already been exposed to the new virus, according to the lead researcher, Dr. Erin Kobetz. She said the change to a more reliable test reflects the flexibility that was always built into the study’s design, a necessity of doing research as a pandemic unfolds in real time.
“We were always aware that there might be a need for us to modify how we were approaching community surveillance, given new knowledge that we couldn’t anticipate at the outset,” Kobetz said.
The rolling survey was announced in late March and started in April, using a rapid finger-prick test developed by BioMedomics. The test came under scrutiny for its chance of producing false positive results, but UM researchers countered that they had further validated the test to understand its limitations and then adjusted for those statistically.
Many scientists and public health officials have scrutinized rapid antibody tests, but they generally agreed they could be suitable for certain population health surveys if other adjustments were made.
Random selection of subjects
In Miami-Dade, countywide finger-prick testing was conducted by randomly selecting people in various areas using phone numbers generated by Florida Power & Light, a selection process that earned praise from scientists. The survey ran three consecutive weeks in April, surveying more than 2,000 people, before the guidance from the FDA came on May 4.
Those guidelines, issued in the midst of a still largely unregulated antibody testing frenzy, stated that antibody testing should be restricted to federally certified labs. Though there was still room for interpretation, UM researchers and county officials decided to heed the call.
“We’re trying to have the most rigorous surveillance that doesn’t fall prey to unnecessary criticism,” Kobetz said.
Kevin Lynskey, the director of the Miami-Dade Water and Sewer Department who is leading the county’s involvement in the project, said he is working to locate a lab that uses a more advanced test designed by Roche, a Swiss healthcare giant. That test, though still lacking full FDA approval, is far less likely to produce false positives, and meets the current guidelines.
The study, meanwhile, is on pause as researchers figure out how the more involved method of antibody testing, which will now require a blood draw, will change the drive-up design, where randomly selected residents drove to a local library, slid down their car windows and stuck their hand out the window.
A COVID-19 patient
Bruce Barham, 70, was one of the randomly selected. He lives in Miami’s Upper East Side, but he never wondered whether he had the antibodies — Barham had tested positive for COVID-19 in late March and even donated his plasma through OneBlood when he heard it could help others.
Barham was intrigued by the antibody testing when he got the call. He said he was tested at the Lemon City Library.
“They had the results almost immediately, but they emailed me the results,” Barham said. “About 10 days after that, they called me back and said, ‘Would you participate in a follow-up?’ ”
That follow-up, which was intended to measure how Barham’s and others’ antibodies changed over time, might not come anytime soon, Kobetz said. It’s one of several aspects her team is reconsidering as they work to figure out how the study will evolve.
“We’re trying to balance our desire for wanting to get back into the field as soon as possible with our approach to how we do it so that it’s as correct as possible, given the limitations of what we all know and don’t know,” she said.
Kobetz, a University of Miami professor of medicine and public health sciences who will become vice provost of research in June, stressed that the survey is a hybrid of sorts: a real-time study that delivers near-immediate results, weighted with as much academic and scientific rigor as possible.
“We don’t have the luxury of a peer review,” she said. “We’re doing it ourselves in real time to ensure that we provide credible results that can inform public health planning.”
This story was originally published May 19, 2020 at 2:44 PM.
