Antibody Study Estimates 4.6% Percent Of Angelenos Have Coronavirus

LOS ANGELES (CBSLA) – An ongoing antibody study being conducted by USC and the Los Angeles County Department of Public Health estimates that 4.65% of Angelenos, or 367,000 people, have contracted COVID-19.

The results of the first phase of the study were published Monday in the Journal of the American Medical Association.

It backed up preliminary results from the study that were released a month ago which estimated that around 4.1 percent of Angelenos had contracted the disease.

The tests were conducted between April 10 and April 14 on 863 randomly selected L.A. County residents. 60% were women, 58% were white and 43% made more than $100,000 per year.

The study concluded that the range of adults in L.A. who have COVID-19 could be anywhere from 2.5% to 7%.

Through Monday, there are now at least 38,451 coronavirus cases in L.A. County and a death toll of 1,839. At least 5,835 people countywide have been hospitalized with coronavirus, which is 15% of all positive cases.

Researchers believe that the number of confirmed coronavirus cases in L.A. County is significantly lower than the actual number of people who have COVID-19. The results also imply that the fatality rate and the hospitalization rate are significantly lower than the official number, researchers said.

"The number of confirmed COVID-19 cases is a poor proxy for the extent of infection in the community," said lead investigator Dr. Neeraj Sood, a USC professor of public policy, in a statement. "We need to update models and forecasts based on new evidence. We're still far away from herd immunity or the end of the epidemic. We need to look at a longer time horizon when evaluating policy decisions."

Herd immunity occurs when at least 60 percent of a population has been infected with a disease.

A second round of testing will conducted on the study participants to continue to examine how coronavirus moves through the population.