There is evidence the Covid-19 vaccine rollout is already reducing deaths, a leading statistician has said.
Prof Jennifer Rogers said there was a sharper drop in deaths among people aged 90 and over compared with those aged 50 to 59, who had not been vaccinated.
“It definitely suggests that it is not an anomaly,” she told BBC Radio Wales.
The first minister said on Sunday that everyone aged 50 and over will receive a first dose by the end of April.
Prof Rogers, who is a member of the Royal Statistical Society, said older people “make up 10% of cases but 80% of deaths”.
Across the UK, she said there had been a 35% reduction each week for the past fortnight in the number of deaths among people aged 90 and over, compared with a 22% drop among people aged 50 to 59.
In Wales, a total of 771,651 people – 24.5% of the population – had been given their first dose of vaccine as of Sunday.
The over-70s, care home residents and staff, health and social care workers, and the clinically extremely vulnerable have already been offered the jab.
There is a similar prioritisation of vaccine rollout in England.
An updated roadmap out of lockdown in Wales is due to be published by the Welsh Government on Friday.
On Sunday, First Minister Mark Drakeford said the government will prioritise the return of three-to-seven year olds to school, along with some older children on vocational courses.
Ministers have started “cautious” talks about Wales’ tourist industry reopening in time for Easter.
People in Wales largely support remaining in lockdown for longer if it means avoiding the “emotional rollercoaster” of going in and out of tighter restrictions, according to an academic.
Simon Williams, senior lecturer at Swansea University’s school of management, told BBC Radio Wales people were not “overly optimistic” of restrictions easing significantly because they had been “burned in the past.”
Mr Williams said surveys from Public Health Wales (PHW) suggested as many as a quarter of people would be willing to stick to tighter restrictions for up to a year if it meant greater freedoms afterwards.
“So people are remarkably willing to stick in lockdown as long as it takes.”
Asked about a vaccine passport, of those people who had received the vaccine, Mr Williams said he believed “the vast majority” would be comfortable carrying “proof of immunity”.
He added it was “inevitable” for a vaccine passports to play a role in international travel in the future.
The proportion of people who have so far refused the vaccine is “negligible” and a “very, very small proportion”, according to Dr Giri Shankar, PHW incident director for Covid-19.
He told Radio Wales the first dose is “offering a level of protection” and that “all indications are suggestive of an improving picture”, but added it was important people received their second dose when called upon.
Fielding questions from listeners, Dr Shankar urged people who had previously been ill with Covid-19 to accept the vaccine.
If people who are in the top four priority groups had not been contacted about a vaccine, Dr Shankar said they should contact their local health board.
All information is available on a dedicated Welsh Government website, he added.