The 41-year-old Good Morning Britain star — who has been vaccinated — said he felt like he had 'really bad flu' and admitted he may have relaxed his mask-wearing and hand-washing precautions in recent weeks.
Beresford tweeted: "Been in bed since last week with COVID. Feels like a really bad flu. I’ve been actively wearing my mask and washing my hands these last few months because I was on projects I couldn’t fall out of, but I know I relaxed up these last 2 weeks and here I am!"
Been in bed since last week with covid. Feels like a really bad flu. I’ve been actively wearing my mask and washing my hands these last few months because I was on projects I couldn’t fall out of, but I know I relaxed up these last 2 weeks and here I am!
— Alex Beresford (@alexberesfordTV) November 29, 2021
He added: "I wouldn’t like to imagine how much worse I would be had I not had the vaccine."
Just days ago the TV presenter, who took part in Dancing On Ice in 2018, urged others to wear their masks in a bid to save Christmas.
Watch: Alex Beresford quits social media over 'relentless' racist abuse
He tweeted: "If making masks mandatory again keeps the country moving and doesn’t stop us from seeing loved ones this Christmas, just wear one and keep another lockdown at bay!"
Last year Beresford revealed he had split from his wife Natalia, with whom he shares 11-year-old son Cruz, just two weeks before the first lockdown began.
Beresford told ITV’s Britain Get Talking podcast: “I hate quitting things,” but revealed that after he and Natalia agreed to separate, “we started to get on better”.
He added: “It removed a lot of the stress and expectation that a relationship can bring.”
Earlier this year Beresford revealed he has faced “relentless racism” since speaking up for Meghan Markle on Good Morning Britain.
The row ended with Morgan storming off and he later quit the show over his refusal to apologise for saying Markle had lied in the interview.
Beresford told The Telegraph: "Since then, I have been subjected to relentless racism myself on social media.
"I am a strong person, but I am not made of steel."
Read more: Keira Knightley 'feeling rubbish' with COVID
Beresford’s cousin Nathaniel Armstrong, 29, was stabbed to death in west London in March 2019, just days after the presenter made an impassioned on-air speech about knife crime.
Watch: Piers Morgan quit GMB after clashing with Alex Beresford in a debate about Meghan Markle