Long Beach on Tuesday reported 403 new COVID-19 cases—the highest three-day total since September—as the highly-contagious omicron variant rips through Los Angeles County.

Monday’s total is more than double from a week ago, which was 182 new cases. The city’s positivity and case rate have also risen steadily and have reached their highest point since September.

The city also reported another two deaths from the virus on Monday, bringing the total number of deaths to 1,065 since the pandemic began.

Los Angeles County’s daily number of new infections, meanwhile, topped 3,000 for the fifth consecutive day. Another 25 virus-related deaths were also confirmed, for a pandemic total of 27,473.

Hospitalizations for now have remained mostly flat, but experts say hospitals could quickly become overwhelmed as more people fall ill.

Speaking before the Board of Supervisors on Tuesday, Los Angles County Health Director Barbara Ferrer said hospital beds could fill unless vaccination rates improve.

“Even if omicron causes half the severe disease delta does … it can still be a major threat for our hospital systems and our residents,” Ferrer said.

She pointed to modeling done by researchers at UC Berkeley that tracked possible hospitalization rates statewide due to the spread of the omicron variant. She said the statewide predictions indicate that with current vaccination levels, the possible hospitalization numbers are “still pretty much a nightmare scenario for our state and L.A. County.”

“We need to work right now to increase vaccinations and booster uptake,” Ferrer said. “These are key.”

According to the most recent figures, 78% of eligible Los Angeles County residents aged 5 and up have received at least one dose of vaccine, and 70% are fully vaccinated. Ferrer said more than 2 million residents have received an additional or booster dose of the vaccine.

In Long Beach, more than 77% of residents ages 5 and up have received at least one dose.

City News Service contributed to this report.