The BBC Radio 2 DJ revealed the news on Twitter that her sibling Frances, who has learning disabilities and diabetes, had tested positive for COVID-19 after an outbreak in her care home.
Jo tweeted: “Feel like I’m in a terrible film with bad posts.
“Late last night I got a call to say that Frances, my sister, had tested positive & has COVID.
“Our worst fears realised after keeping her safe for a year & with a vaccine so close … she’s ok so far … Everything crossed.”
Jo also revealed that she has been offered her own coronavirus jab and admits she would give it up “in a heartbeat” to protect her sister.
The 55-year-old presenter told BBC Radio 4’s Today programme: “I feel like I’m living through a nightmare. The whole weekend has been awful. It’s been really, really difficult.
“And then ironically I got a message to say that I was due to have my vaccine before my sister, who’s got learning disabilities and underlying health conditions.
“I would give up my vaccine in a heartbeat, if I could, for my sister and any of the residents in her house to have their vaccine … it does not feel right.”
Jo is keen to speak up for people like her sister “who have been overlooked”.
She said: “This happens so often people with learning disabilities are neglected, they haven’t got a voice.”
Jo admits that she is unsure why she has been called for her vaccine but believes it could be because she is classed as a carer to Frances.
She said: “I fail to understand, to be honest with you.
“Myself, my parents and the home have done everything we can to try and facilitate the vaccine coming in to the people who need it the most.”