Lupe Fierro, a medical assistant with El Rio Community Health, administers at a COVID-19 vaccination at a pop-up clinic at the Primavera Foundation Homeless Intervention & Prevention Drop-In Center.

COVID-19 cases in Arizona and Pima County have continued to break into an upward trend.

Average daily cases have risen faster in Arizona than the wide majority of states over the previous two weeks, ranking in the top seven states across the country. This is according to data compiled by the New York Times as of Nov. 5.

“This was unexpected,” said Dr. Joe Gerald, an associate professor with the University of Arizona’s College of Public Health. “Something happened in the second week of October to fundamentally change the balance of forces between accelerating transmission and stalling transmission.”

After cases spiked about 44% in Pima County the week of Oct. 17-23, they rose the next week again, this time by 4% to about 2,500 cases, according to data from the Arizona Department of Health Services.

Cases have been rising in most Arizona counties, like Coconino County and Maricopa County. Statewide, cases rose 10% the week of Oct. 24-30 to around 18,400 cases. The week before they had risen 15%.

Gerald called this spike a temporary setback to the state’s underlying gradual improvement in the medium term.

“I think it’s temporary,” he said. “I don’t think it’s a fundamental dynamic change, but I don’t expect us to start improving quickly either. So we’re in this in-between zone where it could be worse, but it could be a lot better, too.”

It was an abrupt rise in cases that happened without any warning, he said, adding that he can’t point to a single explanation for why it happened, since school was already in session and there wasn’t a major holiday or policy change.

Age doesn’t explain the sudden spike either, he said, adding that cases are going up proportionally across all age groups.

“Everybody is going up,” he said. “So we can’t look to what might be going on in workplaces or schools or universities to point the finger at this one.”

Pima County health officials partially attributed the spike to outbreaks of COVID-19 cases in schools that children have brought home to their families.

“A significant increase in the number of cases (is) happening in schools right now,” said Brian Eller, the county Health Department’s school liaison. “Just this last week. We’ve seen an increase by 738 cases within the school systems.”

‘People need to vaccinate’

Statewide and across Pima County vaccinations also increased the week of Oct. 17-23, but it didn’t change the overall vaccination rates in these places by much from last week.

In Pima County, still about 69% of people who are eligible for the vaccine, those who are 12 years and older, have been fully vaccinated, according to Pima County Health Department Director Dr. Theresa Cullen.

Statewide, still about 62% of the eligible population has been fully vaccinated, according to data from ADHS.

“This is a call to the community that people need to vaccinate,” Cullen said. “COVID continues to be a disease primarily of the unvaccinated and it is a very good finder of people that are unvaccinated.”

Those eligible also need to get their COVID-19 vaccine boosters, Cullen said. “If they are six months after the completion of their series, we know that there is a drop-off in antigenicity, which means you have less protection.”

Adults who received Pfizer or Moderna’s vaccine are eligible six months after getting fully vaccinated if they are 65 or older, or if they fall into other high-risk categories.

All adults who received the Johnson & Johnson vaccine are eligible for a booster two months after receiving the initial shot.

Even though vaccine protection wanes after a certain amount of time, researchers still don’t know just how many breakthrough cases are contributing to the latest wave of cases in Arizona, Gerald said.

This is because the ADHS has not linked vaccination data with data on cases for researchers to examine, he said, although he hopes state health officials will do so in the coming weeks.

Those who have been fully vaccinated and got a booster shot have very effective immunity against COVID-19 and are very unlikely to get infected, Gerald said.

If they do get infected they are very unlikely to develop severe illness, even if they are at higher risk of severe illness due to age or an underlying medical condition, he said.

There will be exceptions, he said, adding that a very small number of vaccinated people will still get infected and a small portion of them will end up in the hospital.

“If it gives you a greater peace of mind to avoid certain high-risk situations like going to bars, nightclubs or indoor dining ... I think it’s reasonable to continue participating in those mitigation behaviors that bring you peace of mind,” he said.

Hospitals stable

Hospital capacity seems to be stable in Pima County, but it could quickly turn into a crisis, Cullen said. “As we approach the winter, we remain very concerned about that possibility”

Weekly hospitalizations have not yet followed cases into an uptrend in Pima County or Arizona.

Statewide deaths have been in a slight downward trend since mid September and countywide deaths have been in a straightforward downward trend since September.

If deaths increase, they will lag behind cases by a couple weeks.

While deaths have not spiked, they are still high, Gerald said.

“There’s a lot of virus still out there and we need to do more to keep ourselves, families, communities safe,” he said. “We need to do more because COVID-19 is continuing to ravage our communities and causing substantial morbidity and mortality.”


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Contact reporter Alex Devoid at adevoid@tucson.com or 573-4417. On Twitter: @DevoidAlex