Confirmed COVID-19 cases remain high in San Diego County, with more than 7,000 cases reported for the most recent week data, and experts fear that new strains of Omicron might create a surge in infections, even among those with natural or vaccine immunity, in the coming weeks. The sub-variants BA.4 and BA.5 are quickly taking hold and, like other iterations of Omicron, are increasingly more contagious and equipped to evade existing antibodies. Experts are worried that these new strains could cause more breakthrough cases down the line, as immunity in those who are fully vaccinated or boosted wanes and additional booster shots are not yet widely available according to information about vaccine eligibility on the county's website. “We're seeing people who have been very careful for two-and-a-half years becoming infected with these strains of virus, which I think reflects their really extreme transmissibility,” said Robert Schooley, chief of the UC San Diego Health Division of Infectious Diseases. The number of daily confirmed COVID-19 cases in the county has remained fairly consistent since May when the spread of earlier variants of Omicron, BA.2 and BA.2.12.1, caused daily case numbers to climb to levels rivaling the Delta surge last summer. For the week of June 12, the county had three days in a row where the number of reported cases exceeded 1,600, similar to the daily counts at the height of the Delta wave. While the majority of cases reported by the county up to this point have most likely been earlier strains of Omicron, potential spread in the future could increase even more as BA.4 and BA.5 take hold and more activity occurs due to the lack of restrictions, experts say. MORE: https://www.cbs8.com/article/news/local/inewsource/breakthrough-covid-19-cases-could-be-on-the-horizon-for-county/509-8368c411-d2e1-46b3-9968-1b124c051df4