SAN FRANCISCO (KGO) -- As COVID-19 cases surge in many parts of the Midwest and East Coast, the Bay Area is in good shape. But good enough to avoid a fourth wave, or is that still possible?
"I think it's a distant possibility," said UCSF Epidemiologist Dr. George Rutherford. "That's not to say it couldn't happen in other parts of the state or neighboring parts of the west."
RELATED: COVID-19 surges across multiple states as California numbers continue to drop
Rutherford explains it all comes back to the rate of transmission.
According to ABC7's analysis, over the past week, most of the Bay Area reported a less than 1% increase in case rates per 100,000 people. Napa and Solano counties reported around a 2% increase.
"Two is almost nothing," Rutherford said. "In some of the Midwestern counties, case rates were reaching 56% at some points."
While most of the Bay Area's case rates have stabilized, there are still a record number of COVID-19 variants circulating in California.
RELATED: California doctor not worried about a 4th wave explains why you shouldn't be, either
Rutherford spoke on what he expects to happen if we were to see a fourth wave.
"If it were to happen, it would happen sooner rather than later," he said. How soon? As soon as two weeks.
Rutherford explains it's all about the pace of vaccinations, and right now is the most vulnerable time as California waits for additional vaccine supply to meet the demand of those eligible.
Gov. Gavin Newsom said Tuesday that California received 2.4 million vaccines this week. The hope is that supply will grow to 3 million per week by early May.
"There's not a lot of transmission going on right now, but there's still 2,500 new COVID-19 cases per day in California," said Rutherford. "We want it to be at zero."
RELATED: These 5 states accounted for 43% of new COVID-19 cases in the U.S. in the past week
UCSF Dr. Monica Gandhi explains the only way to get close to zero is by reaching herd immunity.
"You reach a certain point of the population that's vaccinated and you keep your prudent restrictions on which we need to do, then cases start coming down because vaccines do stop transmission," said Gandhi.
As of Wednesday, 43% of Californians have received at least one dose.
Rutherford said California will be closer to herd immunity levels once at least 60% of the state's population has received at least one dose. At that point, it's estimated those who have naturally-acquired immunity will raise the state's immunity level from 60% closer to 80%.
Having trouble loading the tracker above? Click here to open it in a new window.
RELATED STORIES & VIDEOS:
- Map shows which counties can, can't reopen under reopening tiers
- Cheat sheet: What you can and can't do after being fully vaccinated
- How to register for a COVID-19 vaccine in every Bay Area county
- Map shows everywhere you can get a COVID-19 test in the Bay Area
- Interactive map shows what's closed and what's reopening in the San Francisco Bay Area
- Data tracker: Coronavirus cases, deaths, hospitalizations in every Bay Area county
- Third stimulus check calculator: See how much you could get
- COVID-19 Diaries: Personal stories of Bay Area residents during pandemic
- Get the latest updates on California EDD, stimulus checks, unemployment benefits
- Coronavirus origin: Where did COVID-19 come from?
- What is a COVID-19 genetic, antigen and antibody test?
- What does COVID-19 do to your body and why does it spread so easily?
- Coronavirus Timeline: Tracking major moments of COVID-19 pandemic in San Francisco Bay Area
- Coronavirus Doctor's Note: Dr. Alok Patel gives his insight into COVID-19 pandemic