The Duke and Duchess of Cambridge have urged people to get the Covid vaccine, saying it is "really important".
Prince William said the uptake so far had been "amazing" but added: "We've got to keep it going so the younger generations also feel that it's really important for them to have it."
The royal's comments came during a video call with two women who have been shielding since last March.
He also warned against fake news about the jab on social media.
More than 19.6 million people have now had their first dose of the vaccine. And the number of people who have had their second dose has topped 760,000, latest government figures show.
Prince William and Catherine spoke to Shivali Modha, who has type 2 diabetes, and Fiona Doyle, who has severe asthma, during the video call. The two women are both eligible for the vaccine as they are in priority group six, and were preparing to have their jabs.
Ms Modha, 39, from Barnet in north-west London, said she was initially anxious about having the jab after reading things on social media, but had been reassured by vaccinated family members and medics.
Prince William told her: "Catherine and I are not medical experts by any means but if it's any consolation, we can wholeheartedly support having vaccinations. It's really, really important.
"We've spoken to a lot of people about it and the uptake has been amazing so far. We've got to keep it going so the younger generations also feel that it's really important for them to have it.
"So it's great that, Shivali, you're taking the time to work it out and come to the conclusion that 'I need to do this,' because social media is awash sometimes with lots of rumours and misinformation, so we have to be a bit careful who we believe and where we get our information from.
"Especially for those who are clinically vulnerable as well, it's so important that those vaccinations are done, so good luck."
The duchess added: "I hope [the vaccine] comes as a huge relief in the end. I know there's maybe the anxiety and the worry leading up to it, but I hope for all of you it will add a bit of normality back to your lives and confidence as well as we go forward into the spring, that would be great."
Ms Modha thanked the duke and duchess for speaking with her and said she wished she could offer them a cup of tea, to which Catherine replied: "Same here."
Currently, the government's aim is to offer a jab to all over-50s by 15 April, as well as people aged 16-64 with certain underlying health conditions and unpaid carers for disabled and elderly people.
After that, they will start offering jabs to people by age group, with the hope that all adults will be vaccinated by the end of July.
There are no plans yet to vaccinate children, although trials have been announced to test the jab on children.
Earlier this week, Prince William visited a vaccination centre and spoke to staff and people waiting for their jabs.
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