New COVID-19 cases are on the rise in Pima County and across Arizona, a trend that has public health officials worried about another surge ahead of the holiday season.
In Pima County, daily case counts hit 637 on Nov. 9 – the first time daily rates topped 600 since January, according to the Arizona Department of Health Services data dashboard.
Weekly case counts have also surpassed summer 2020 levels, when cases first surged in the county.
Back then, new COVID-19 cases in Pima County peaked at about 2,500 a week in early July. During the first week of November, new COVID-19 cases topped 3,500 in the county, according to ADHS.
While it's clear cases are rising, the reason for the rapid increase is harder to pinpoint, Pima County’s Chief Medical Officer Dr. Francisco Garcia said during Tuesday’s Board of Supervisors meeting.
“It’s complicated, and it’s multifactorial, and I’m not sure that we really deeply understand this yet," Garcia said.
"But one of the things that is clear is there is waning immunity that is happening about six months after the second dose of the vaccination,” he said.
Though counts are still well below the peak of last winter’s surge, when cases rose to nearly 8,000 in Pima County and over 62,000 across the state during the first week of January 2021, Garcia said the case growth remains a concern.
“We have a residual proportion of the population that remains unvaccinated. As of (Monday), the CDC was reporting that a full 60.5 percent of the population of Pima County was fully vaccinated, but that means that 40 percent of folks are unvaccinated, and that remains a source of vulnerability and a potential threat,” Garcia said.
Hospitals, ICUs and breakthroughs
As a result of the recent case increases, hospital bed availability has decreased at medical facilities throughout the county and the state over the past three weeks.
According to a Nov. 16 memo to the Pima County Board of Supervisors, local hospitals reported having 4 percent intensive care unit availability on Nov. 14, with 25 percent of ICU beds in use by COVID patients.
Statewide, about 8 percent of Arizona’s 1,782 adult ICU beds are available, and about 32 percent were occupied by COVID patients as of Nov. 15, according to ADHS data, representing about a 20 percent increase from the beginning of the month.
During Tuesday’s board meeting, Supervisor Matt Heinz, a physician at Tucson Medical Center who represents most of Sahuarita, said he’s seen the increase in COVID hospitalizations first-hand.
“At my hospital, we have gone from one COVID unit plus part of an ICU to now an entire ICU unit plus three or four full or partially full COVID units,” he said.
“Having a near doubling of COVID patients in the past three to four weeks in my own hospital, as well as all the others in the county, is a serious problem that should not be minimized.”
Though the recent surge is largely happening among the unvaccinated – about 76 percent of all COVID cases in October occurred in individuals who were not fully vaccinated, according to the health department – Heinz emphasized that waning vaccine immunity means the county must double down on efforts to deliver booster doses to the older population.
“Where I was seeing only one or two (breakthrough cases) out of a number of months... I’ve seen half a dozen just in the past couple of weeks in my own practice, which I know is amplified beyond just me,” Heinz said.
According to ADHS data, there have been nearly 50,000 confirmed breakthrough cases – where fully-vaccinated people get COVID – reported from people who received the COVID-19 vaccine in Arizona.
According to the Pima County Health Department, about 1.25 percent of all fully-vaccinated Pima County residents have had a breakthrough case, and about 198 fully-vaccinated individuals in the county have required hospitalization since the beginning of the pandemic.
“There are older members of the county who have underlying chronic medical conditions that may make their immunity perhaps not as robust to the initial vaccinations – they are the ones coming in with breakthrough cases if they have not yet gotten a boost,” Heinz said.
In response to the rise in community transmission, the Pima County Health Department issued a public health advisory Monday strongly recommending all eligible adults get vaccinated, get boosters and get their age-eligible children vaccinated as soon as possible.
"We are seeing some of the highest COVID-19 infection rates and hospitalizations since the surge last winter," Dr. Theresa Cullen, the Pima County Health Department Director, said in the press release.
"It is likely that all residents in Pima County can be exposed to COVID-19 where they live or work, and that is why we urge 18 years and older to get their booster."
The CDC has already affirmed the need for boosters among all adults who received the single-dose Johnson & Johnson vaccine at least two months ago, as well as for those 65 and older who completed either the Moderna or Pfizer vaccine series at least six months ago. Adults who fall into certain other high-risk categories are also eligible to receive a booster within that time frame.
According to the CDC, more than 89 percent of adults aged 65 or older in Pima County are fully vaccinated, and another 10 percent have received at least one dose. But as of Nov. 2, only about 10 percent of fully-vaccinated adults in the U.S. had received a booster, including about 25 percent of those aged 65 and older.
Garcia noted Tuesday that in addition to encouraging eligible individuals to get vaccinated and boosted, the health department will also be working to ramp up testing to monitor the recent spike in cases.
Last week, the county administered nearly 33,000 diagnostic tests – about the same rate the county was testing last November – and has disseminated an additional 92,000 BinaxNOW rapid take-home tests over the past few weeks, which Garcia said will be especially useful during the holiday season.
“We need to be doing the kind of testing that provides results that are rapidly actionable so that when you got to a holiday party with your grandparents, before you walk in the door you’re able to do that rapid antigen test and figure out whether you really should be putting them at risk or not,” he said.
The health department continues to strongly recommend frequent hand-washing, wearing a mask in indoor public spaces and remaining at home if you are sick to combat the high transmission rate in the county.