"We're going to have a pretty significant surge over the next couple weeks," said UCSF's Dr. Bob Wachter.
SAN FRANCISCO (KGO) -- Will the Bay Area avoid another lockdown? One of the state's top COVID-19 experts says we need to bring back a full mask mandate to make that happen.
COVID cases and hospitalizations across the Bay Area are rising at a pace we haven't seen since the onset of our biggest surge in November.
"We're going to have a pretty significant surge over the next couple weeks and one that really surprises me," said Dr. Bob Wachter, the chair of the Dept. of Medicine and UCSF.
"This virus is just twice as good at its job."
Wachter says he was confident once San Francisco reached 70 to 75 percent of the population was vaccinated we would be in 'good shape' -- a model for the rest of the country.
"That would've been true if we're dealing with the old virus," he said. "But, we're not."
Over the past three weeks, on average new COVID infections in the Bay Area have increased five-fold and hospitalizations have more than doubled.
Stephanie: "Do you think it's possible?"
Wachter: "It sort of depends on what we do. I think we are catching this early enough and the percentage of vaccinated people is high enough that the likelihood that we're going to see a surge that threatens to overwhelm our hospitals is very low. But, it's not zero."
While Wachter is cautiously optimistic, he's also not ruling out another lockdown. He says UCSF Medical Center went from zero COVID hospital patients six weeks ago to 25 as of Tuesday morning.
"If we get back to where we were at the worst parts of the pandemic with 100 to 150 people in the hospital, then I think we have to do more than what we're doing," he said.
Stephanie: "Do you think the entire Bay Area will go back to mandating masks indoors?"
Wachter: "Oh. I think it's 100 percent likely... I think their fingers health officials have to be pretty close to the trigger on this one."
Dr. Wachter says he would be surprised if the Bay Area doesn't have a mask mandate back in place within one week.
ABC7's data analysis found the Bay Area's seven-day rolling average of new daily COVID cases jumped from 231 on July 1 to 1,335 on July 23. The average spiked more than five times in a mere three weeks.
"The surges tend to last a couple of months if you look at what we've seen so far," said Wachter. "Delta seems to last a little shorter than other surges."
Wachter says even if a sizeable portion of the population gets vaccinated today, we're still going to have one or two tough months ahead.
"Everybody needs to get vaccinated because Delta isn't the end of it," said Wachter. "There will be new variants that come out."
Wachter says certain groups will need to start getting booster shots within the next couple months. He expects it will be phased out in groups like the initial vaccination rollout.
Who is in group one? Wachter expects once a booster is authorized -- immunocompromised patients, people 70 and older, anyone who got their first shot in December or January and possibly even those who received the Johnson and Johnson vaccine, since the single-dose has a slightly lower level of protection.
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