Here’s when local experts say the delta surge could peak in the SF Bay Area


The highly contagious delta variant is driving a wave of new COVID-19 cases across the San Francisco Bay Area, setting a key to a long-awaited “return to normal life.”

In the three largest regions, Alameda reported an average of seven days off 19.6 case per 100,000 residents on Monday, Santa Clara 11.6 per 100,000 and San Francisco 27.9, according to the state COVID dashboard. For perspective, these counties were all reported less than 2 cases per 100,000 on June 1st.

The good news is that deaths are incredibly low and hospitalizations are not nearly as high as they were at the January peak because of high vaccination rates in the region. But the wave is still regarding, triggering new mask warrants, putting people who aren’t vaccinated at risk and leading many to ask, “Will this end? When can I put away my mask again?”

We spoke with several local experts to get their perspective.


When will the virus rise?

As with all COVID predictions, experts cannot provide a timeline and certainty as multiple factors, including the person’s behavior and vaccination rates, are at play that could change the course of the virus. “Essentially I don’t know when the peak will occur and there are many unknown factors that will determine that,” Dr. Annie Liu, an infectious disease doctor at Stanford’s infectious disease clinic, wrote in an email.

Dr. Julie Parsonnet, an infectious disease physician at Stanford’s infectious disease clinic, offers optimism because of the region’s high vaccination rate. In San Francisco, 70% of all residents completed a series of shots. That number rises up 78% when you only look at residents 12 and older.

“Unfortunately, I don’t have a crystal ball and try to never predict the future,” Parsonnet wrote in an email. “However, the rate of transmission depends on the number of susceptible individuals. Sensitivity depends on vaccination status, underlying immune status, and willingness to use masks and avoid high-risk environments. Given the relatively high rate of vaccination in SF and the renewal of masking. indoors, I imagine the peak will come relatively soon, in the next week maybe. “

Dr. George Rutherford, an infectious disease physician at UCSF, said that models developed in collaboration with UCSF and UC Berkeley set new cases to reach their peak in “the next week, mid- to late August.” He said the models are based on immunity and how many people mix.

Rutherford said hospital admissions are likely to rise early in mid-September.

How will this peak be different than the one in January?

While cases are rising rapidly, experts agree the delta peak will be less severe than a January’s because of vaccinations, which are proven to prevent serious illness and death. Even though people who are vaccinated occasionally become infected, so-called breakthrough tools rarely lead to serious illness or death, The Centers for Disease Control and Prevention said.

“This peak will and is different from the one in January as hospitalized by following cases along the same trajectory,” Dr. Monica Gandhi, an infectious disease expert at UCSF, explains. “With relatively high vaccination rates in the Bay Area, hospital admissions remain much more controlled being with the high cases last January – this‘ decoupling ’of cases from hospital admissions is certainly not complete, but the connection is detachment . “

Parsonnet said the Bay Area’s peak trajectory looks similar to one that has unfolded in the United Kingdom, where a delta wave is driving down. “If you look at the UK, although they did have a summer peak, the death rates were very low compared to the winter and I expect SF will be similar,” he said.

When do you think the indoor mask term will fall?

Experts agreed that counties throughout the Bay Area are likely to release the mask warrant in accordance with the CDC guidelines based on the number of new cases occurring in the community.

“When, as there is now, there is greater than‘ substantial ’transmission (> 50 cases per 100,000 per week or> 8% positivity rate), masks will be required indoors,” Parsonnet wrote. “San Francisco is now, I believe, in about 34 cases per 100,000 per day or> 200 per week. So they have a way to go to get low and release the indoor mask warrant. Maybe sometime in September. ” (San Francisco reported an average of 28 cases per day Monday.)

Gandhi agrees: “Although some experts have argued for a hospital metric (<5 hospital admissions / 100K population) to release the restrictions, the CDC will be on a metric case and recommend masking of the substantial or secondary transmission area," he said. write in an email. . “... So I’m sure the Bay Area will follow CDC guidelines and release the mask warrant once [we're] below the substantial level to moderate level of transmission. "

Rutherford predicted the mask’s term should rise in “mid-October,” adding, “That’s a wild guess.”

He said: “I think we have to see what happens on schools and children’s first vaccinations.” “Nobody likes it, but you don’t want to take it off and then have to put it back.”

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