The Younger star took to Instagram Story on Friday to reveal that she contracted a breakthrough case of the coronavirus and detailed her symptoms.
"That delta...she's a little b*tch," Duff, 33, wrote alongside a photo of herself laying in bed. "Symptoms: bad headache. No taste or smell. sinus pressure. Brain fog. Happy to be vaxxed."
According to the CDC, breakthrough cases are COVID-19 infections that happen in people who have been fully vaccinated. There will be a small percentage of fully vaccinated individuals, as "no vaccines are 100 percent effective at preventing illness." Some, however, may be asymptomatic or illness will be "less severe for those who are vaccinated."
Duff's news comes just days after she started production on her new show, How I Met Your Father. On Tuesday, she shared a behind-the-scenes pic from the set. In the snap, she's accompanied by her co-stars, Francia Raisa, Chris Lowell, Suraj Sharma, Tien Tran, Tom Ainsley and Brandon Micheal Hall.
"Who’s ready for us???" Duff captioned the pic. "We may or may not have been sitting in front of a certain someones apartment…."
Meanwhile, Duff isn't the first celebrity to contract a breakthrough case of COVID-19. Melissa Joan Hartrevealed her diagnosis on Instagram earlier this week, telling her followers in a video, "I am vaccinated and I got COVID and it's bad."
"It's weighing on my chest. It's hard to breathe," she said, adding that she, as well as one of her kids, contracted the virus due to her sons' return to school.
Shortly after her first post, Hart provided an update to her followers, telling them that she was "feeling better today," and encouraging them to "mask up, isolate, and test constantly!"