A COVID-19 antibody study in Ventura County found that less than 1.3 percent of individuals tested in a two-week period had antibodies in their blood, indicating a small percentage of the population has been infected with the virus.

The study, conducted by a group of local universities, companies and public agencies, tested 6,794 people between June 22 and July 6. Of them, 87 had developed protective antibodies in their blood.

Matthew Fienup, executive director of the Center for Economic Research and Forecasting at California Lutheran University, one of the universities involved in the study, said the researchers were surprised at how few people tested positive for antibodies.

“This provides evidence that the very early and very complete shutdowns which were imposed in Ventura County succeeded in slowing the transmission of the disease,” he said in an email to the Business Journal.

However, he added the low rate of positivity also means much of the population is still at risk of contracting the virus. That could imply economic lockdowns into the future.

“We simply can’t afford to lock the economy down as we did in early spring, so a highly targeted approach will be required in order to protect the lives and livelihoods of those who are most at risk in the county.”

The study took place over a two-week period, representing one incubation cycle, or the average time it takes for a person to be exposed to the virus, develop symptoms and recover.

Participants who reported their race or ethnicity as Hispanic, Black, or other non-Hispanic, had higher positivity than those reporting as White or Asian (1.8 percent, 2.3 percent, and 1.9 percent, respectively, compared to 1 percent and 0.9 percent).

The research group comprises the University of California Irvine, University of California Los Angeles, California Lutheran’s Center for Economic Research and Forecasting, 11Health, the Ventura County Healthcare Agency, Oxnard Fire Department, Ventura City Fire Department and others.

Testing consisted of a blood withdrawal and a questionnaire and was conducted for free at several temporary centers throughout the county.