Douglas Birdt started a Facebook group titled Breakthrough COVID-19 Cases.

"The reason I started the group is because there really isn't any places where people with breakthrough cases can talk with other people who have breakthrough cases,” said Birdt.

With almost 100 people in the group, members share the concern and shock associated with being vaccinated and infected, though the chances of people getting COVID-19 while vaccinated always existed.

"Vaccines can prevent infection, very rarely does that happen. It can prevent all disease, very rarely does that happen. It can prevent severe disease, hospitalization and death. That's the bucket we're trying to be in,” said Upstate Medical University Chief of Infectious Diseases Dr. Stephen Thomas.

He said the term "breakthrough" causes too much confusion about what's happening. He said vaccinated people getting COVID-19 is not unusual. No vaccine is 100% effective.

"What matters is your endpoint. What are you measuring?” said Thomas.

The Centers for Disease Control reported that as of July 12, nearly 5,500 vaccinated people in 48 states were diagnosed with the coronavirus and were either hospitalized or died. Of that, just over 5,000 were hospitalized and 1,063 of those hospitalized died.

That's out of the 159 million people vaccinated in the U.S., and as the delta variant is being transmitted in communities.

"Even with that. All three vaccines are very protective against the delta variant, and again, will reduce the risk of serious illness, hospitalization and death, which brings it back to if you're vaccinated, you're more protected than someone who's not,” said Dr. Phillip Falcone, chief medical officer at St. Joseph’s Health.

New York has seen an uptick in positive cases and hospitalizations.

The Associated Press reported that 8,700 vaccinated people tested positive in New York, though that data does not specify the type of infection and does not include hospitalizations.

As of this week, federal health officials say the delta variant is responsible for 83% of all COVID-19 cases in the U.S.

Unvaccinated people make up more than 97% of all COVID-19 related hospitalizations.

"It could happen here. It's just a matter if people have the will to not let it happen, which I hope people will have the will to do. We did it once. We're in this situation because people made good decisions, so hopefully, they can do it again."