The county reported 290 more infections, raising the total since the start of the pandemic to 259,985.
Hospitalizations increased from 126 on July 20 to 143 on July 21, with the number of intensive care unit patients dropping from 59 to 35.
“Basically, this is Delta,” said Andrew Noymer, an epidemiologist and University of California–Irvine professor of population health and disease prevention, on the rising number of cases.
“The fall has come early because we have a more transmissible variant.”
Public health professionals had expected a mild summer because of vaccination rates and more outdoor activity, but that cases would increase when the temperature drops and more people head indoors and children return to school.
“COVID was ultimately going to be a seasonal phenomenon,” Noymer said. “But last summer we were punching through the seasonality because it was new and we were native to it—no immune system experience.
“But this summer we have a lot more vaccinated and some other people who are survivors of natural infection so you would expect less COVID, but it’s punching through again because we have this new variant that is highly spreadable.”
According to the weekly averages released on July 20, Orange County’s case rate per 100,000 residents increased from 2.6 to 4.9 and the test positivity rate jumped up from 1.8 percent to 3.3 percent.
The county’s Health Equity Quartile rate, which measures the disadvantaged communities hardest hit by the pandemic, increased from 1.9 percent to 3.4 percent.
The state releases weekly averages on Tuesdays.
The county had recently been reporting coronavirus statistics once per week, but switched on July 19 to releasing numbers every weekday in light of the increasing number of infections.
There were no new fatalities logged on July 21. The cumulative death toll remained at 5,136.
The death toll for July is one. The death toll for June is 15; 22 for May; 43 for April; 198 for March; 610 for February; 1,563 for January—the deadliest month of the pandemic—and 967 for December, the next deadliest.
Noymer said the death rate should increase in a few weeks or a month, but not at the level from the winter.
“I do expect the death rate to decline somewhat because the older people tend to be more vaccinated, so the cases are skewing younger,” Noymer said.
About 95 percent of the patients hospitalized are unvaccinated, according to county officials.
The high number of unvaccinated patients is “hopefully a reminder to the public that when they seek the risk of COVID, they would ask questions, get educated, and consider the voluntary vaccine,” Orange County chief executive Frank Kim said July 20.
The county had 1,851,432 fully vaccinated residents out of its 3.2 million population as of July 15, according to the Orange County Health Care Agency.
Vaccination rates have flattened to levels not seen since January when they were being rolled out mostly to seniors, first responders, and health care providers.
Orange County officials have not discussed any sort of new mask order, Kim said.