LI's Melissa Joan Hart reveals she has 'bad' case of breakthrough COVID

"Sabrina the Teenage Witch Star" Melissa Joan Hart revealed in a tearful 2-minute Instagram video that she has contracted a case of breakthrough CO-VID.

"I am vaccinated and I got COVID, and it's bad," the Smithtown-raised actress said from her sickbed in the video. "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."

Hart, 45, said she likely caught the disease from one of her children who was not masked while at school.

"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," Hart said. She and her musician husband, Mark Wilkerson, have three children — Mason Walter, 15; Braydon Hart, 13, and Tucker McFadden, 8, whom she praised in the video for wearing his mask to school every day.

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

She concluded by saying the pandemic "is not over yet. I hoped it was, but it's not, so stay vigilant and stay safe."

Breakthrough cases, in which a vaccinated person can still get the disease, are rare but possible. According to the Centers for Disease Control and Prevention website, as of Aug. 9, more than 166 million people in the United States had been fully vaccinated. Of that total, the CDC said there have been 8,054 reported breakthrough COVID-19 cases.

Hart first gained fame as a teen in the early '90s as the star of the Nickelodeon sitcom "Clarissa Explains It All" which ran from 1991 to 1994. She had an even bigger success with the comedy series "Sabrina the Teenage Witch," which ran from 1996 to 2000 on ABC and then for three more seasons on The WB.