Edinburgh author Ian Rankin says the vaccination programme "seems to be a bit of a lottery" amid frustration his son is yet to receive the jag.
26-year-old Kit has severe learning difficulties and despite living in care didn't qualify for the first priority group.
His dad says he should have been prioritised earlier, and lessons need to be learned by government so that more people aren't "forgotten".
Rankin told BBC Radio Scotland: "Our son can't look after himself and he's in the same group as us - his parents who are healthy 65-year-olds. People with learning difficulties should have been prioritised.
"My son will get the jag in the next month or so. But we should learn lessons for the future about what seems to be a bit of a lottery."
Rankin believes there should have been better communication with families throughout the whole programme.
He added: "The families and the carers have been kept out the loop.
"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."
The Scottish Government say that the priority groups are decided based on risk of mortality from Covid-19, and that risk is low in those under the age of 40. They say their focus has been on protecting those most vulnerable to losing their lives to the virus in line with the JCVI priorities.
As of February 17, 1,320,074 people have received their first dose of vaccine, with 20,409 receiving their second jag.
