Jo Whiley felt "utterly powerless and angry" when her sister was unable to get a coronavirus vaccine.
The 55-year-old DJ's younger sibling Frances, 53, has genetic disorder Cri Du Chat syndrome, which results in delayed development, and though care home residents were among the first to be eligible for the jabs when the programme was rolled out in the UK in December, her sister's local GP insisted she wasn't "in the right tier" to be vaccinated.
She told Good Housekeeping magazine: "I remember watching breakfast TV and they were saying: 'Everyone in care homes is being vaccinated.'
"I thought, 'Hang on, Frances is in a care home - no they're not'. When I contacted her GP, they just said, 'She's not in the right tier; we can't do anything.' "
While awaiting her vaccine, Frances was admitted to hospital after falling seriously ill when she contracted the virus following an outbreak in her home, and her battle with the illness only made Jo feel more angry on the behalf of people with disabilities, who she felt had been "neglected".
She said: "I felt utterly powerless and angry, too. As the nightmare unfolded and Frances became ill, I had this rage inside me. I realised how people with disabilities had been neglected, because they don't have a voice."
The BBC Radio 2 presenter hailed her husband Steve Morton for his strength and support over the last year.
She said: "Because we're so different, I'm quiet and calm and Steve's loud and vivacious. I also now appreciate what a good team we are.
"When we were going through these horrific decisions with Frances, he was there, asking the right questions and helping my parents. I saw a strength in him that I'd never seen before."
Frances ultimately recovered from the virus and went on to be vaccinated in March.
