California COVID-19 Case Rates Now Twice Florida – Why?

A month ago, it appeared that coronavirus was heading for a long winter nap in masked and well-vaccinated California. Governor Gavin Newsom boasted that the Golden State “continues to lead the nation” as the only state to reach the Centers for Disease Control and Prevention’s yellow “moderate” level of transmission of community viruses.

But COVID-19 cases are no longer falling in California. They have climbed back up to CDC’s blood red “high” level of virus transmission as the highly contagious Delta variant continues to wreak havoc.

Meanwhile, the virus has become quiet in the Deep South states, which gave up mask orders, opposed vaccine mandates, posted lower vaccination rates and experienced major outbreaks over the summer. California’s case rate is now well above Texas’ and the double Florida’s, which along with the rest of the Gulf Coast are down to the CDC’s orange “significant” transmission level.

“There are early indications that the decline in Delta growth at the national level in the United States is complete,” said Ali H. Mokdad, a professor of health metrics at the University of Washington who runs a widely followed model projection of the course of the pandemic. Currently, 19 states have increasing transmission, including several such as California “which previously appeared to have been declining.”

And while much of Golden State’s current corona problems are driven by virus spread in the less vaccinated and restricted inland counties, the Bay Area has not been immune. Most Bay Area counties that were hoping to reach the yellow moderate level now remain stubbornly stuck in orange. Marin and Santa Cruz counties, which had reached the yellow level, is back to orange. San Francisco is the only county in yellow.

For Bay Area residents, this has real consequences. Local health officials have reintroduced the indoor face mask, regardless of vaccination status, and say they will only revoke the order after their counties have fallen below the orange level for three weeks, among other conditions.

So why are Golden Staters not reaping more rewards for their adherence to health care while the virus gives freewheeling Dixie a break?

“You pay for your success, which is strange,” Mokdad said. “You managed to control the virus, and now you have infections.”

But he and other health experts say it is not because the health guidelines are not sound. Outbreaks appear to be exacerbated when the virus runs out of enough new people without the immunity to infect. And people can gain immunity both from infection recovery and vaccines.

With higher vaccination levels than in the Southeast, California experienced a smaller wave of cases over the summer as the Delta variant ripped through the country, mostly infecting those who had not been vaccinated. Now that they have recovered, they also have immunity, which cuts off the pathways for the virus to spread.

“These regions are now partially protected by high past infection rates,” said Dr. Bob Wachter, President of the Department of Medicine at the University of California-San Francisco. “But these people, whose immunity comes from COVID, are not very well protected, and their immunity will diminish over time.”

While California’s vaccination rate compares well with many other states, it’s still not enough to snatch outbreaks. Currently, 62% of California’s total population is fully vaccinated, compared to 60% in Florida, 54% in Texas, 49% in Georgia, 48% in Louisiana, 46% in Mississippi, and 45% in Alabama. It still leaves more than one in three Californians unvaccinated.

In California, indoor face mask orders imposed over the summer to schools across the country and to other public buildings in the Bay Area and Los Angeles also helped keep the virus at bay. But the state’s unvaccinated – especially those who have not been infected – remain vulnerable.

States in the southeast that have been hammered with large increases in summer cases are now doing better, simply because with their combination of vaccinations and infections, they have fewer people left susceptible to the virus than in California, Mokdad said. But “they got there at a high price.”

Other factors also come into play. The hot, humid summers of the Southeast drive people to the air-conditioned indoors, where the virus spreads easily, while Californians enjoy moderate weather out in the surf and sand. But the autumn cold is now also bringing Californians inside.

What’s more, immunity through vaccination or infection decreases with time. Californians who were quick to line up for vaccines in early spring are now wondering how long their protection will last.

Booster shots have mainly been approved for older adults, people with weakened immunity or people with high exposure risk, which will spur their protection against infection. But among those 65 and older, only 30% in California got the extra chance, equivalent to the 29% in Texas and 27% in Florida.

Mokdad said immunization of newly eligible children and unvaccinated adults, giving booster shots and encouraging or requiring wearing masks can dull a expected increase in the number of infections in winter. Will people listen to the call?

“California has done very well over the last few months, but we still have too many unvaccinated people,” Wachter said. “People spend more time inside and are more active, and the masking is falling.”

Combined with declining immunity and low booster uptake, he said, “the end result is that we have the plateau in our improvements, both nationally and in California, and it is likely that we will soon see some significant increases.”