In a rapid attempt to stanch the spread of COVID-19, Gov. Gavin Newsom on Monday issued new orders to pull the "emergency brake" on the virus, pushing San Mateo County back into the red tier or substantial risk of infection, and Santa Clara County back two tiers from orange (moderate risk) to purple (widespread risk), the most restrictive. The change is effective starting Tuesday, Nov. 17.

“We are sounding the alarm. California is experiencing the fastest increase in cases we have seen yet -- faster than what we experienced at the outset of the pandemic or even this summer. The spread of COVID-19, if left unchecked, could quickly overwhelm our health care system and lead to catastrophic outcomes. That is why we are pulling an emergency brake in the Blueprint for a Safer Economy," Newsom said. "Now is the time to do all we can -- government at all levels and Californians across the state -- to flatten the curve again as we have done before.”

The return to a red tier will mean that San Mateo County restaurants must limit indoor dining to 25% of capacity and other businesses, such as fitness centers, will face additional restrictions.

Under the purple tier, restaurants can have outdoor service only and only outdoor gatherings in Santa Clara County are allowed for places of worship, museums, family entertainment centers, movies, and professional sports (without live audiences). All retail, including shopping malls, are restricted to 25% of capacity. A full list of what's regulated can be found here.

Santa Clara County officials had already announced on Nov. 13 that they would again ban indoor dining and add other yet-to-be determined restrictions to public gatherings in response to a rapid rise in COVID-19 cases.

It was the second time in a week that the county addressed the growth in coronavirus cases. Leaders said the new restrictions come as the infection rate and hospitalizations have continued to increase since Nov. 3. The increased infection rates within the county mirror trends seen across the Bay Area, the state and in many other parts of the country, county Health Officer Dr. Sara Cody said at a press conference. Other health officers in most Bay Area counties are expected to announce similar restrictions, she said last Friday.

"Unfortunately, I'm here to deliver more sobering news," Cody said. "It is absolutely imperative that we take action now."

The local curve has been shooting "straight up" since about Nov. 3, she said. "The steepness of that curve required that we act swiftly."

On Nov. 16 during a press conference in San Jose, Cody reiterated the importance of adhering to state and county guidelines regarding social distancing, wearing masks and business compliance with restrictions.

Santa Clara County had 388 new confirmed cases on Nov. 16. Although she did not yet have a count of new hospitalizations, on Nov. 13 she said there were 110 hospitalizations, an increase from an average of 80 hospitalizations per day in October.

She added an urgency on Monday: "We have done this before. We can do this again. We need every citizen and business in our county to take this extremely seriously," she said.

Santa Clara and San Mateo counties were in the less-restrictive orange tier, but rather than waiting 72 hours to implement the new restrictions, the state has moved up enforcement to Tuesday. Santa Clara County had expected a step backward into the red tier, but the state also shortened the lag in data, which is why the county was pushed into the purple tier, County Counsel James Williams said on Monday.

Schools that have not yet opened will be prohibited from reopening until at least two weeks after the county is removed from the purple-tier designation. Those schools having already reopened can continue without interruption, and those in phased reopening can continue to reopen under their phased schedules under the state's law, he said. Elementary schools can also seek waivers based on their individual safety plans, he added.

San Mateo County’s transition back to the red tier does not impact the operation of schools or the process for returning students to in-person instruction, according to a statement from the county Office of Education. "Education is considered an 'essential' activity by the state – not a gathering – and, therefore, is not impacted by the state’s recently updated guidance on gatherings," the statement said.

Erik Burmeister, superintendent of the Menlo Park City School District, said that the model that Menlo Park City School District and others have implemented to reopen schools has managed risks and allowed students and staff to experience the benefits of in-person learning. "As a society, if we sacrifice to keep anything open during a pandemic, it should be our schools. Districts throughout San Mateo County are showing how that can be done,” he said in a statement.

Santa Clara county is working on a plan for how to distribute COVID-19 vaccines when they become available, Cody said. Since there are many different types, they will likely fit different groups and will have different storage and handling requirements, complications that will make logistics complex, she said on Monday.

Williams and Cody reiterated statements they made last Friday about the effectiveness of stepping back with more restrictions as the number of cases rise.

"One of the lessons we have learned and demonstrated in March and July (when there were also steep rises in COVID-19 cases) is that acting quickly helps bring things under control faster," Williams said last Friday regarding the county's decision to move faster to implement the restrictions than state guidelines.

Santa Clara County Board of Supervisors President Cindy Chavez said on Friday that she realizes that people are growing weary of the restrictions.

"As a community we tried really hard to fight this back," she said. "So this is really bad news and it's really hard to hear. We've all got to dig in and really double down."

She noted that many schools plan to reopen in January or this spring, but that could be hampered by the growing virus rates.

"It is a call to action," she said, "to do a little more or to return to being more vigilant if people have been slacking."

Watch the full press conference:

Find comprehensive coverage on the Midpeninsula's response to the new coronavirus by Palo Alto Online, the Mountain View Voice and the Almanac here.