Coronavirus Antibody Testing To Begin In Sonoma County

SONOMA COUNTY, CA — Coronavirus antibody testing is set to begin soon in Sonoma County. Testing for antibodies is to take place daily starting Saturday at the Public Health Lab in Santa Rosa, with plans for strategically expanding this service at select hospitals and health centers in the county.

"The new antibody testing is part of a larger surveillance effort to better understand the spread of the virus," county health officials said. "We initially plan to perform approximately 110 antibody tests per day with the goal of testing 3,500 people within the next four weeks as all testing sites become operational."

The first phase of antibody testing will be for first responders such as paramedics, EMTs, firefighters and law enforcement, as well as people who previously tested positive for COVID-19 and have since recovered.

First responders are considered high-risk for exposure to the coronavirus and thus have a greater likelihood than the general population of having contracted COVID-19 and subsequently developing antibodies, the county said.

The prioritized testing is also reserved for high-risk groups that include family/household members and close contacts of people who previously tested positive for the virus. Sonoma County Department of Health Services will contact residents who have recovered from COVID-19 and their close contacts to schedule an antibody test.

The testing is not currently for the general public and is being done for surveillance purposes. The county says it will use antibody test data to evaluate its efforts toward slowing the spread of the coronavirus, and to help county officials make decisions about reopening.

Once more antibody testing sites and increased appointment capacity become available, the county says it will provide more information to the general public.

Antibody Testing: What To Know

According to the county, the antibody test does not check for the presence of the virus itself; rather, it reveals if a person's immune system has responded to the infection.

Depending on when someone was infected and the timing of the test, the test may not find antibodies in someone with a current COVID-19 infection because it can take one to three weeks after infection for antibodies to be detected.

The antibody tests processed at the Sonoma County Public Health lab require a blood draw from a vein. The test has a high-degree of accuracy, meaning that nearly 90 percent of those who test positive for antibodies had COVID-19 and nearly 100 percent of those who test negative did not have the virus.

While antibodies consist of proteins that typically help fight off infections, the county says it is not yet known if having antibodies to the coronavirus can protect someone from getting infected with the virus again, or how long that protection might last.