The preliminary results of a UC Berkeley study measuring the spread of COVID-19 among East Bay inhabitants were released Tuesday and showed low rates of COVID-19 positivity among participants over the summer.

The East Bay COVID-19 study, which is being conducted by UC Berkeley professor of infectious diseases and vaccinology Eva Harris and campus professor of epidemiology Lisa Barcellos, will consist of several rounds. The results were compiled from the data observed in the first round, which lasted from July to September, according to Harris.

“We are in a situation where people’s behavior is key to ending this pandemic, so any kind of surveillance data that monitors what is happening in a geographical region is super helpful,” Barcellos said. “It just adds to the body of knowledge regarding what is taking place in the community.”

Invitations to partake in this study were extended to 300,000 households in the East Bay region, according to Harris. Of the 15,000 who filled out the questionnaire, the team selected a “largely” random sample with an emphasis on minority groups, Barcellos said.

Harris added that the participants of the study were a good representation of the Bay Area in terms of demographics.

All participants in the sample were sent a biospecimen collection package that included a saliva collection vial, a nasal swab kit and a blood spot collection kit, Barcellos said. About 5,200 packages were returned, Harris noted.

“Round one results showed that, during the period, which was July to September, there was a pretty low rate of current infection across our study population in those 12 cities,” Barcellos said.

The study found that less than 1% of participants tested positive for COVID-19, and less than 1% of participants tested positive for COVID-19 antibodies, Barcello said. The presence of antibodies can help scientists track past exposure to the virus.

For those who tested positive for COVID-19 antibodies, the study found that 69% were women and 17% were Hispanic, Harris noted.

According to Barcellos, the full results collected from the first round of the study have not yet been released.

“We have a lot of additional data that we haven’t put out yet surrounding social factors and other health outcomes such as employment and how people were responding to the pandemic,” Barcellos said.

According to Harris, the study was a “Herculean” effort due to restrictions implemented by the county and UC Berkeley.

Harris added that it was difficult to spend time in communities and gain the trust of potential participants due to the shelter-in-place order. 

“Professor Harris and I are really grateful for the continued efforts of our study participants,” Barcellos said. “This is not possible without their participation and it’s really difficult to do a study of a pandemic in a pandemic and so we’re really glad they have stayed patient with our request.”