The Coronavirus continues to spread across California. There have been more than 68,000 new cases in the last week and nearly 350 more deaths. Hoping to reduce the surge, Governor Gavin Newsom has ordered most people to stay home, starting Saturday, from 10 p.m. to 5 a.m.

The drugmaker Moderna announced on November 16 that its coronavirus candidate vaccine was 94.5 percent effective, joining Pfizer as a front-runner in the global race to contain a raging pandemic that has killed 1.2 million people worldwide. Both companies plan to apply within weeks to the Food and Drug Administration for emergency authorization to begin vaccinating the public.

AstraZeneca announces promising results

The biopharmaceutical business AstraZeneca announced on November 13 that early analysis of its late-stage clinical trials in Britain and Brazil showed that its coronavirus vaccine was 90 percent effective when given in one dosing regimen, but only 62 percent effective in a different regimen.

Governor Gavin Newsom announced an 11-member scientific safety review workgroup has been set up to independently review any federally approved coronavirus vaccinations, which could be available in very limited supplies sometime this calendar year.

“These experts will independently review and monitor any vaccine trials to guarantee safety, to guarantee equity, and to guarantee transparency of the distribution of our vaccines,” he said, listing UCLA, UC San Diego, Stanford, and UC Berkeley among panelists affiliations.

Despite the president’s repeated claims that a vaccine will be available in October, scientists, companies, and federal officials all say that most people won’t get one until well into next year. Mr. Newsom expects the vaccine would be widely available in the middle of next year, reports The New York Times.

Officials are also working with the Centers for Disease Control and Prevention to begin planning vaccine distribution in advance, working out the logistics of how they will supply vaccines to some 40 million residents.

“We have roughly that many people just in our health care delivery system alone,” he said in an October 19 news conference talking about the two million available vaccines for the whole state. “Don’t anticipate or expect that you can go down to a local pharmacy anytime in this calendar year and likely get a vaccination.”

How will the vaccines be distributed?

According to California health officials, who published a working draft of their vaccine distribution plan, the vaccine will be rolled out in three phases.

Phase 1A will provide the vaccine to paid and unpaid people working in health care settings who have the potential for direct or indirect exposure to patients, and for health care workers who can't work from home.

Phase 1B will provide the vaccine to other essential workers, and people at higher risk for severe COVID-19 illness, including people 65 years and older.

Phase 2 will supply the vaccine to the remainder of the Phase 1 populations that weren't able to receive a vaccine due to limited supplies. In addition, other critical populations and essential workers will be provided the vaccine. As more vaccines are available, they will be distributed to the general population.

Phase 3 will provide vaccines to the general population and make the vaccine part of routine health care practices.

What are the challenges to rolling out a vaccine?

Two coronavirus vaccine candidates now lead the pack. Moderna, a Massachusetts-based biotech firm, announced on November 16 that its vaccine is 94.5% effective in preventing COVID-19. It's the second company to report positive results from the final stage of clinical trials: On November 18, Pfizer and BioNTech reported that their vaccine was found to 95% effective.

Both Moderna and Pfizer's vaccines require two shots. Moderna's two doses are administered a month apart, while Pfizer's are given three weeks apart. The Moderna vaccine is stored frozen at minus-20 degrees Celsius, but it keeps for a month at refrigerator temperatures. This could make it easier to distribute to pharmacies and to rural areas that don’t have specialized freezers.

The vaccine from Pfizer and BioNTech must be kept at an ultracold, minus-70 degrees Celsius. The company has created its own GPS-tracked coolers filled with dry ice to distribute it.

Vaccination resistance may be a significant challenge. Overcoming this resistance may require addressing vaccine safety concerns, hostility to big pharma, religious beliefs, fear, unsubstantiated anecdotes, or political dogma. Thus, any vaccination campaign could find itself fighting on multiple fronts simultaneously.

What happens next?

Mr. Newsom said he expected the vaccine would be widely available in the middle of next year. Both Pfizer and Moderna are already mass-producing their vaccines, and Moderna officials say the company will have close to 20 million doses ready by the end of 2020.

However, it’s still not guaranteed that these vaccines will receive approval from the FDA, because more data still need to be collected, points out Dr. Chris Gill, an immunologist at Boston University who is not working on coronavirus vaccines.

Is it safe to go out for Thanksgiving?

Governor Newsom, his wife, and their four children are quarantining for two weeks after three of the kids were in contact with a California Highway Patrol officer who tested positive for Covid-19. Newsom’s office said the entire family tested negative Sunday. The CHP provides security for the governor and the first family.

With cases of COVID-19 spiking across the state, the Newsom administration announces a curfew for counties with the highest rates of transmission.

Dr. Bob Wachter, chair of the UCSF Department of Medicine, joins Marisa and Guy Marzorati to react to the announcement and shares his thoughts on Governor Newsom's leadership, coronavirus response during the presidential transition, vaccine development, and weighing joy and risk during the pandemic.

Across the country, public officials are urging people to stay home and stay safe during the upcoming Thanksgiving holiday amid a dramatic rise in new cases of COVID-19 in nearly every state.

“It’s hard to make sacrifices,” Dr. Wachter said of Thanksgiving plans this year. “But this is one that a lot of people are going to regret not having made.”