The chair of Care Forum Wales said it is a "race against time" to ensure those who need the vaccine most are able to get it as soon as possible.
Mario Kreft raised concerns that the vaccine might be too late in reaching vulnerable residents at a time when many care homes across Wales are at crisis point.
Mr Kreft said: “It’s clearly fantastic news that the Oxford-AstraZeneca coronavirus vaccine has been approved but it’s vitally important that it is rolled out very quickly because were are now in a desperate race against time, especially since this new super-strain of Covid-19 is so highly infectious and out of control, with community transmission rampant.
“Every care home manager will have everything crossed that the vaccine reaches their residents before the virus. There is great trepidation in the social care sector that it might not come soon enough.
“Residents in all care homes should be given absolute priority – along with the staff who provide care for them. Because of their age and infirmity, our vulnerable residents are uniquely at risk from this deadly virus."
The Health Minister said the Oxford-AstraZeneca vaccine will arrive "in small quantities initially, with more of our population-based allocation arriving each week."
The Oxford-AstraZeneca vaccine's approval has been described as a "game changer", with the UK having ordered 100 million doses of the vaccine - enough to vaccinate 50 million people.
Residents and staff in care homes for older people are at the top of the priority list for those receiving the vaccine.