Scottish crime author Ian Rankin says his son Kit has been "forgotten" as vaccines were delivered to care homes.
The 26-year-old - who has severe learning difficulties - lives in care in Edinburgh, but did not qualify in the first priority group.
Rankin told the BBC he believes those in Kit's circumstance "should have been prioritised".
The Scottish government said it had "rightly" prioritised those at higher mortality risk.
People with a "severe or profound" learning disability are in priority group six for the coronavirus vaccine.
This means Kit will receive his vaccine after his father.
Speaking to BBC Radio Scotland's Drivetime programme, Rankin said people who have family members with special needs feel "let down" by the programme.
He said: "Our son has severe learning difficulties, he has suffered epilepsy in the past, he can't look after himself in any way, shape or form, and he's in the same group as us - his parents, who are healthy 60 to 65-year-olds.
"It's a bit late now. My son will get the jab in the next month or so. But we should learn lessons for the future about what it seems to be a bit of a lottery."
A previous BBC investigation heard that not enough consideration was given to disabled people and their complex needs when lockdown came into effect - and this had a continued impact over the summer.
Rankin said he had not spoken to an MP or MSP about his family's circumstance, believing they would "just pass the buck".
While he has sympathy for the government dealing with the pandemic, he said more could have been done earlier to ensure people who are learning disabled were not as badly affected.
"The families and the carers have been kept out the loop," he said.
"Life's hard enough for them. This year has been tough without any of the usual services, treatment, education they usually get.
"The idea they're just being forgotten about sitting in isolating in their care homes.
"Both governments keep telling us it's wonderful they've got all the care homes done. No, you haven't. You've got care homes for the elderly done. There's more care homes than that out there."
'They don't have a voice'
Rankin also shared his frustration over how his son's residence was classified as a care home during lockdown but not for the vaccine programme.
"The disabled don't have a voice," he added. "They've never had a voice and laterally we're starting to hear their representatives, their family and friends, yelling".
The Scottish government said evidence suggested risk of serious Covid-19 was associated with age and that mortality is low in those aged under 40, "even for individuals with clinical risk factors".
A spokesman said: "We have rightly focused first on the people who are the most vulnerable losing their life, to stand the chance of saving as many lives of possible with the vaccine, in line with JCVI priorities.
"We have now given first doses to more than a million people, including elderly care home residents and staff, frontline health and social care workers and those who are at risk of serious harm and death from this virus."