"I got COVID," she told her 1.6 million followers in a video posted to Instagram on Aug. 18. "I am vaccinated, and I got COVID, and it's bad."
The 45-year-old actress then described her symptoms, noting "it's hard to breathe" and felt like she had a weight on her chest. Hart—who shares sons Mason, 15, Braydon, 13, and Tucker, 8, with husband Mark Wilkerson—also expressed her concern over the potential of her family members getting infected.
"One of my kids I think has it so far," she said. "I'm praying that the other ones are OK."
The Sabrina the Teenage Witch star suspected the virus was spread at her children's school.
"I'm mad, really mad," she said, "because we tried and we took precautions and we cut our exposure by a lot. But we got a little lazy, and I think as a country we got lazy. And I'm really mad that my kids didn't have to wear masks at school because I'm pretty sure that's where this came from."
Although, Hart said her youngest child continued to wear his mask because he was used to wearing one last year.
"He came home bragging every day, 'Mom, I wore my mask.' And I was so thankful," she said. "And now, if he does get it, I can at least tell him he was a superhero to those in his classroom because he protected his teacher and his classmates from it."
Hart then expressed her frustration. "I'm just scared and sad and disappointed in myself and some of our leaders and a lot of people," she continued, "including myself."
According to the Centers for Disease Control and Prevention, "Only a small proportion of fully vaccinated people get infected (breakthrough infections), even with the Delta variant."
"Moreover, when these infections occur among vaccinated people, they tend to be milder than among those who are unvaccinated," the CDC states on its website. "However, preliminary evidence suggests that fully vaccinated people who are infected with the Delta variant can be infectious and can spread the virus to others. To reduce the risk of becoming infected with the Delta variant and spreading it to others, students, teachers, and school staff should continue to use layered prevention strategies including universal masking in schools."
In her caption, the Clarissa Explains It All alum noted she "wasn't posting this to be political or gain pity" but to share her journey.
"This isn't up for debate," she wrote, "it's just how I feel today on my page."
At the end of her video, Hart sent a message to her fans. "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. I'd hoped it was, but it's not. So, stay vigilant and stay safe."