Findings from a coronavirus antibody study released by Miami-Dade County Friday revealed that approximately 6 percent of the county’s population, or approximately 165,000 people, have COVID-19 antibodies. That percentage lines up with findings in Santa Clara, Los Angeles, and New York State (excluding the hot spots around New York City).
There are a few methodology differences between the Florida study and others completed to date:
UM researchers say their findings are more robust than most because they used Florida Power & Light to generate phone numbers in targeted demographic areas, leading to a more randomized selection of participants.
The study, spurred by Miami-Dade County officials, will be an ongoing weekly survey based on antibody testing — randomly selecting county residents to volunteer pinpricks of their blood to be screened for signs of a past COVID-19 infection, whether they had tested positive for the virus in the past or not. The goal is to measure the extent of infection in the community.
By testing of 1,400 adults for a population of just over 2 million, Miami-Dade’s sample size is far greater than Los Angeles County’s study, which tested approximately 830 adults to represent a population of 6 million.
An interesting finding from the Florida study is that about half of the people who tested positive didn’t have any symptoms in the 14 to 17 days before the test. It’s unclear whether those people had ever had symptoms, but gives insight into how many people have been infected but were asymptomatic.
Erin Kobetz, the lead researcher on the study, said that the study follow certain participants to measure their antibodies over time, and will expand to include voluntary testing in hard-hit areas.
Of course, officials say that even with these results it’s more important than ever to “stay the course” and practice social distancing.