Breakthrough covid cases jump in Allegheny County

Breakthrough covid-19 cases in Allegheny County have risen in recent months, according to data from the Allegheny County Health Department.

Breakthrough infections accounted for 23% of cases in August, Allegheny County Health Director Dr. Debra Bogen said Wednesday as she shared the first county-specific breakthrough data.

The instances of breakthrough cases have risen since June, when they constituted 18% of cases, and July, when they made up 7% of cases, she said.

“Before June, breakthrough cases were rare,” Bogen said.

The county’s data addressed a narrower timeline than the data provided by the state Department of Health, which relied on data dating back to January, when vaccination rates were lower and the highly transmissible delta variant was not yet fueling new spikes in cases.

Acting Health Secretary Alison Beam on Tuesday said that 5.5% of covid-19 cases in the commonwealth from Jan. 1 through Sept. 7 were breakthrough cases — those that occur in fully vaccinated individuals who received their second dose of the Pfizer or Moderna vaccine or one dose of the Johnson & Johnson jab at least 14 days prior.

In more recent months, “it’s not surprising” that breakthrough numbers are rising, said Dr. Amesh Adalja, a Pittsburgh-based infectious disease expert and senior scholar at the John Hopkins Center for Health Security.

“One of the main things is the prevalence of the delta variant,” which is likely causing an increase in breakthrough cases, Adalja said.

He said people have also become more aware of breakthrough cases, leading to an influx of fully vaccinated individuals being tested for the virus “even if there wasn’t a clinical need.” Before awareness about breakthrough infections, vaccinated individuals, he said, were less likely to be tested after potential exposure.

Nonetheless, Bogen said, the data “supports what we’ve been saying for months: the vaccines work.”

In August, 10% of patients hospitalized with the virus in Allegheny County were fully vaccinated, Bogen said. Statewide, about 5% of patients hospitalized because of covid-19 were fully inoculated, according to data from the Department of Health.

Deaths among fully vaccinated individuals in Allegheny County “remain uncommon,” Bogen said.

Statewide, 97% of covid-19-related deaths occur in unvaccinated individuals, according to the Department of Health.

“Breakthrough hospitalizations and deaths were among the very elderly, frail with underlying health conditions and those with severe immune deficiencies,” Bogen said. “In other words, the vaccines continue to do their job.”

Adalja, too, said that these breakthrough cases are not a sign of vaccine failure.

“When it comes to what matters, the vaccines are holding up extremely well,” Adalja said. “The goal of the vaccines was not to prevent every breakthrough case but to make breakthrough cases very mild, to not cause serious illness, hospitalizations or death.”

This comes as the county continues to see covid-19 cases climb. The PCR positivity rate within the county, Bogen said, jumped from 5.4% last week to 6.2% this week.

Deaths increased from 11 in July to 54 in August. So far in September, the Health Department has reported 21 covid-19-related deaths, Bogen said. The average age of those who succumbed to the virus in July was 80, but it dropped to 72 in August, with deaths last month ranging from individuals ages 41 to 99.

Bogen urged “vigilance” against the virus — for both vaccinated and unvaccinated individuals. She encouraged people to wear masks, especially in crowded settings and in schools, where the state Department of Health has mandated their use.

Some virus cases, she said, have been traced back to bigger events. But there haven’t been “enormous spikes” from large gatherings like football games, she said.

Bogen, along with Allegheny County Executive Rich Fitzgerald, strongly encouraged people to get vaccinated, pointing to the data showing breakthrough infections, hospitalizations and deaths remain rare.

As more event venues, including Stage AE, the Pittsburgh Cultural Trust and some restaurants begin to require proof of vaccination, Fitzgerald said those who are unvaccinated may be incentivized to get the inoculation.

“I think the folks who aren’t vaccinated are really isolating themselves from the rest of society,” he said.

Fitzgerald said he applauded the Biden administration “for the very strong stance they have taken” in mandating that all employers with more than 100 workers require the vaccine. Allegheny County, he said, is considering making vaccination a condition of employment for its workers as more employers mandate the shots. Many major employers in the region were scrambling to process the new mandate after it was announced last week.

In Allegheny County, Fitzgerald said, nearly 75% to 80% of the eligible population — those ages 12 and older — is at least partially vaccinated.

Among county employees, about 74% are fully vaccinated, with others partially vaccinated, he said.

Fitzgerald credited the county’s “tremendous” hospital systems and relatively high vaccine uptake for helping keep hospitals in the region from being stretched thin as they have been in some parts of the country. Bogen said hospitals, including UPMC’s Children’s Hospital, “plan for surges” and can expand ICU capacities if needed.

Allegheny County on Wednesday reported 417 additional cases of covid-19, with 134 of those individuals age 18 or younger. The Health Department on Wednesday also reported 15 new deaths, all of which occurred in September.