Generate an appropriate single-sentence summary for the given text such that it includes the main topic of the text.

Health boards have called on people to contact them if they have not yet had an appointment for a jab. It comes as the number of people who have died with coronavirus in Wales passed 5,000. In north Wales, Betsi Cadwaladr University Health Board, said it had appointments available this week. The call comes after it was confirmed more than 600,000 people in Wales have been given their first dose of a Covid vaccine as Wales overtook the other UK nations for the first time in the percentage of the population getting a first jab dose. People aged over 70, or in high priority groups, had been urged not to call their GPs or health board for an appointment, with letters being sent to households. But health boards in Wales have now put out messages urging those in the top priority groups - over 70s, those classed as "extremely clinically vulnerable", and any NHS or social care workers - who have not been contacted to get in touch. However, they have warned they were being "inundated with calls" and urged those who were not yet due the vaccine to wait to be contacted. On Monday, the UK government urged people over the age of 70 in England, who had not yet been given an appointment, to contact their health board "urgently". Cardiff and Vale University Health Board urged people in priority groups one-four to get in touch, with people aged 75 or over being told to call their GPs. "We will start scheduling cohorts 5, 6, and 7 from 15 February and will update you on how you will be contacted," the health board said. Hywel Dda health board chief executive Steve Moore said he was confident everyone in groups one-four would have been offered the vaccine in the west Wales area by Monday. Anyone aged 70-74, or classed as clinically extremely vulnerable, or shielding, are being urged to contact the health board's booking centre. "However, people change phone numbers or move to a new house and may not always update their contact details with health services," he said. "This is why we want to make absolutely sure no one has missed an appointment for their vaccination." There had previously been criticism that the vaccination rollout in Wales had faced a slower start than the rest of the UK. Wales' aim is to ensure just under 750,000 people - including health workers and people aged over 70 - get a first dose by mid-February. A Welsh Government spokesperson said: "We have been asking people to wait until contacted directly by the NHS. However, as the pace of our vaccination programme increases, we are starting to ask people over 70 to get in touch if they haven't been invited for their vaccination."

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
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People over the age of 70 or extremely high risk living in parts of Wales are being urged to call the NHS to book in for their Covid-19 vaccination.