"I think as a country we got a little lazy and I'm really mad that my kids didn't have to wear a mask at school," Melissa Joan Hart said

Melissa Joan Hart has contracted a breakthrough case of COVID-19.

The Sabrina the Teenage Witch alum, 45, revealed her diagnosis in two-minute video shared to her Instagram on Wednesday, saying that she likely caught the respiratory virus from one of her children.

"I am vaccinated and I got COVID, and it's bad," she said told fans. "It's weighing on my chest. It's hard to breathe. One of my kids, I think, has it so far. I'm praying that the other ones are okay."

The actress — who shares sons Tucker McFadden, 8, Braydon Hart, 13, and Mason Walter, 15, with husband Mark Wilkerson — went on to explain that she and her family had taken precautions throughout the pandemic, but "got a little lazy" as restrictions were lifted.

"I think as a country we got a little lazy and I'm really mad that my kids didn't have to wear a mask at school. I'm pretty sure where this came from," she said.

Melissa Joan Hart

Hart then applauded her youngest son for continuing to keep up with masking, saying that he wore one to school every day "because he was used to it from last year."

"I just really hope my husband and the other ones don't get it, because if someone has to be taken to the hospital, I can't go with them," she said.

"I'm just scared and sad, and disappointed in myself and some of our leaders," Hart continued. "I just wish I'd done better, so I'm asking you guys to do better. Protect your families. Protect your kids."

"It's not over yet," she added of the ongoing pandemic. "I hoped it was, but it's not, so stay vigilant and stay safe."

Breakthrough cases — COVID-19 infections that occur in people who have been fully vaccinated against the virus — are rare, but possible and expected, as the vaccines are not 100% effective in preventing infections. Still, vaccinated people who test positive will likely be asymptomatic or experience a far milder illness than if they were not vaccinated. The majority of deaths from COVID-19, around 98 to 99%, are in unvaccinated people.

COVID-19 cases had been on the decline as Americans got vaccinated, dipping down to around 11,000 a day in early June. But as the delta variant became the dominant strain in the United States, cases again soared back to levels not seen since February, when the vaccines were not readily available to all Americans. The biggest increase in cases have been in southern states like Louisiana, Missouri, Arkansas and Florida, all of which have some of the lowest vaccination rates in the country.

Currently, children under the age of 12 are at risk of contracting the virus as they are not eligible to receive the vaccine.

As a precaution, the Centers for Disease Control and Prevention (CDC) have recommended universal indoor masking for all regardless of vaccination status.

As of Thursday, 51.1 percent (169.5 million) of the nation's populace is fully vaccinated against COVID-19, according to data from the CDC, while 60.2 percent (199.8 million) have received at least one dose.

As information about the coronavirus pandemic rapidly changes, PEOPLE is committed to providing the most recent data in our coverage. Some of the information in this story may have changed after publication. For the latest on COVID-19, readers are encouraged to use online resources from the CDC, WHO and local public health departments. PEOPLE has partnered with GoFundMe to raise money for the COVID-19 Relief Fund, a GoFundMe.org fundraiser to support everything from frontline responders to families in need, as well as organizations helping communities. For more information or to donate, click here.