The vast majority of Pennsylvanians who have contracted the coronavirus in 2021 were not vaccinated, state officials said Tuesday, releasing new data on infections they said should persuade all eligible residents to get their shots.

Through early September, there have been nearly 640,000 positive cases of COVID-19 across the state, close to 35,000 hospitalizations, and almost 6,500 deaths. But 97% of the deaths were in people who were unvaccinated or partially vaccinated, according to state data, as were 95% of hospitalizations and 94% of confirmed cases.

“The vaccine is continuing to do its job even against more recent variants including the delta variant,” acting Health Secretary Alison Beam said at a news conference. “No vaccine has 100% efficacy, so post-vaccination cases are to be expected. It’s important to also remember that COVID-19 vaccines were developed to help people stay out of the hospital and avoid death, not just [avoid] positive cases.”

It was the first time the state provided data on cases in vaccinated people; the data are for the entire state, including Philadelphia. The Inquirer reported in June that Pennsylvania was not tracking the so-called breakthrough cases, six months into the vaccine rollout. New Jersey and Delaware were already doing so, as were other states and even Philadelphia. They’ve also reported the vast majority of the newly confirmed cases have been in unvaccinated people.

The Department of Health preferred to focus on providing other coronavirus data, a spokesperson told The Inquirer at the time.

Since then, however, the situation has changed, due to the emergence of the highly transmissible delta variant, against which the vaccines may be slightly less effective. While fully vaccinated people are still less likely to get sick with the virus, and far less likely to be hospitalized or die if they do get infected, scientists have found that they can spread delta.

Pennsylvania’s new data showed the case rate among vaccinated residents was 819 per 100,000 and the death rate was 7 per 100,000 — making unvaccinated people seven times more likely to be infected and eight times more likely to die than those who are immunized. The state didn’t release a post-vaccination hospitalization rate.

It also isn’t complete, because only 55% of hospitals and 69% of acute-care facilities reported the required information. The Department of Health recently ordered all hospitals to begin reporting the data, which are current as of late Tuesday, and is working with those that haven’t yet complied or don’t have the capability to compile the data, which Beam said requires “multiple systems.”

Beam said her department would continue working with hospitals to improve data reporting and in the future provide more detailed information, such as linking breakthrough cases and the vaccine each patient got before becoming infected.

The data will be updated at least monthly, she said.

“The data that we have is showing once again that even as the more transmissible delta variant becomes more widespread, the COVID vaccines are safe, are effective, and help prevent serious illness and death,” Beam said.

» READ MORE: Philly-area COVID-19 cases are leveling off, but health community is ‘bracing for an uptick’ heading into fall

With delta’s emergence, case rates have risen over the summer but remain much lower in Pennsylvania than in most other states, something experts say is likely due to the state’s relatively high vaccination rates. Still, health officials have warned of the continuing rise — including among children — and urged the 35% of residents 12 and up who aren’t fully vaccinated to get their shots.

The state’s seven-day average of newly confirmed cases has been above 3,000 per day for several days. On Tuesday, more than 3,700 new cases were recorded statewide.

“Our health-care teams are tired,” said Michael Ripchinski, chief clinical officer for Penn Medicine Lancaster General Health. “They’re burned out. Our businesses are struggling to recover. Our teachers and students want to keep our schools open. Vaccines provide us with a way out of this. Vaccines enable us to return to normal.”

Major hospitals across the state are reporting an increase in unvaccinated coronavirus patients, according to the Department of Health.

“Over the past several weeks, we have seen as much as 19 times more non-vaccinated patients ages 50 and younger admitted to UPMC hospitals compared to vaccinated patients,” said Dr. Donald Yealy, chief medical officer at University of Pittsburgh Medical Center.

At Penn Medicine, Ripchinski said, unvaccinated people tend to be more likely to end up in the ICU and have longer hospital stays. Fahad Khalid, chief of hospital medicine at Penn State’s hospital, said about half of unvaccinated patients need intensive care compared with less than one-quarter during earlier surges.

The doctors said vaccinated people recently admitted to their hospitals tend to be immunocompromised or have mild cases and are admitted for an entirely different reason.

“When fully vaccinated people develop symptoms from COVID-19 in a breakthrough infection, they tend to be less severe symptoms,” Ripchinski said. “Those who are vaccinated are much less likely to be hospitalized or to die.”

Pennsylvania’s breakthrough case numbers are in line with those reported nationwide and in neighboring states, which have remained relatively consistent since the early summer.

In New Jersey, 0.35% of more than 5.3 million fully vaccinated residents have tested positive for the virus as of Aug. 30, state officials said Monday at a news briefing.

Of those, 386 have been hospitalized, they said, and 97 have died. They represent 0.007% and 0.002% of vaccinated people, respectively.

Meanwhile, in Delaware, 0.45% of its nearly 506,000 fully vaccinated residents have had confirmed virus cases as of Sept. 10.

Only 50 of these breakthrough infections resulted in hospitalizations, the state Division of Public Health said, and 25 immunized people died, though the virus might not have been the cause of death in every case.

For the week of Aug. 30 to Sept. 5, 87% of Delaware’s confirmed cases and 90% of its virus-related hospitalizations were in unvaccinated individuals, the state said.

“The number of breakthrough cases has increased over time, in Philadelphia and across the country. Epidemiologically, this is an understood phenomenon that happens when the majority of the population is vaccinated,” Philadelphia health department spokesperson James Garrow said, noting the vast majority of the city’s cases remain among people who have not been vaccinated. “More vaccinated people means more opportunities for breakthrough cases.”

“What isn’t counted in our counts of breakthroughs is severity,” he added. “It’s understood that breakthrough cases tend to be more mild than unvaccinated cases.”

The delta variant has caused an increase in testing, which appeared in the Philly region to include many vaccinated people wanting to find out if their sniffles were a cold or a breakthrough case. Still, breakthrough cases may also be underreported because people who are vaccinated may generally be less likely to get tested for COVID-19.

» READ MORE: COVID-19 cases among Pa. school-age children are 10 times higher than they were last year

The CDC only requires states to report hospitalizations and deaths among vaccinated people.

The state was one of only three that couldn’t provide those data, according to a national August analysis by the New York Times. That analysis, through early August, showed breakthrough hospitalizations and deaths made up as much as 5% or 6% of those reported in some states and less than 1% in others.

In announcing Pennsylvania’s breakthrough case data Tuesday, Beam said: “My hope is that this data encourages everyone who has not yet been vaccinated to speak to their doctor about getting the vaccine as soon as possible.”

Correction: A previous version of this article incorrectly said Pennsylvania had not released post-vaccination case and death rates and misstated the post-vaccination case rate in Delaware.