A star-filled video urging people from ethnic minority communities to get the Covid vaccine will be shown across the UK's main commercial TV channels later.
Sanjeev Bhaskar, Meera Syal and Romesh Ranganathan are among the celebrities who feature in the video, which has previously been released online.
More stars have been added to the version that will be screened on ITV, Channel 4 and Channel 5 at 21:56 GMT.
STV and various Sky TV channels will also take part in the TV "roadblock".
The film will not be shown on the BBC because the corporation's charter prevents it from taking part in campaigns, but the issues it raises and some of the participants will feature on BBC TV and radio programmes on Thursday.
Citizen Khan creator Adil Ray, who co-ordinated the video, said: "We are in unprecedented times and the fact remains this pandemic disproportionately affects people from ethnic minority communities.
"It's heartening to see all the major broadcasters come together in an equally unprecedented television broadcast at this crucial time."
The campaign comes amid growing concern about the uptake of Covid vaccines among black, Asian and other ethnic minority communities in the UK. Official figures suggest that people from ethnic minorities are less likely to get vaccinated.
The latest evidence comes from a study published overnight of GP records looking at vaccine take-up among people.
Fake news about the vaccine has been a particular problem in the South Asian community, and is addressed in the #TakeTheVaccine video.
"There's no chip or tracker in the vaccine to keep watching where you go," says comedian Ranganathan in the film. "Your mobile phone actually does a much better job of that."
The video also rebuts claims that the vaccine contains animal products and is not halal, or that it causes infertility.
'Degree of separation'
Ranganathan told BBC Breakfast on Thursday he and his brother had to sit down with their mother - who has previously appeared on his show The Ranganation - to talk through her concerns about the vaccine.
"My mum is a key worker, where she works it's a lot of people from South Asian backgrounds and so my brother and I were obviously very worried about her and we just assumed that she was going to be willing and ready to take the vaccine," he said.
"And then when it came down to us actually discussing it with her, she said, 'I've actually got some doubts', and so it took us by surprise but we were able to talk to her about and explain the various issues and now she feels OK to take it."
He added: "But it just feels so heart-breaking to me that people from ethnic minorities are inflicting a degree of separation upon themselves from not trusting in this, and I understand all the reasons why - I've heard all the arguments - but I just feel so strongly that we need to make sure we dispel some of these myths, so that people are getting involved and we can get ourselves out of this pandemic."
'Fighting two pandemics'
Appearing on the programme alongside the comedian, Dr Farzana Hussain said she hoped that such celebrities could have a key influence.
When asked if she had noticed a shift in attitudes yet, she replied: "Not hugely sadly, I know it's still early days and I think that's why it's so important to keep repeating the message.
"I have an 18-year-old-son and he would never take a message from me or a doctor, but when I told him that I was going to be on TV with Romesh, he was so excited about it.
"We obviously have a place as doctors, but I think everybody has a place, and I think this message is going to be a long, hard one.
"As Dr Nikki Kanani - our GP leader - has said: we are fighting two pandemics here. We're fighting the Covid virus, but we're also fighting this huge tsunami of misinformation that's coming out."
Singer Beverley Knight, Olympic heptathlete Denise Lewis, historian David Olusoga and actor Hugh Quarshie are among the stars in the video's latest version.
The three-and-a-half minute broadcast will also be shown at a webinar event addressing vaccine hesitancy in ethnic communities, to be introduced by the Prince of Wales on Thursday morning.
In his video address, Prince Charles will say he has been "saddened" by "the variable uptake of the vaccines which finally offer us a way out of the suffering of the past year".
Speaking to Radio 4's Today programme, broadcaster and historian David Olusoga said he understood why people from ethnic minority backgrounds may be wary, due to the "entanglements in history between the history of medicine and the history of colonialism and racism".
"There is a history that is well known, and that helps fuel people who are spreading misinformation," he said. "But the reality is that although there is a chequered and disturbing history, vaccines are safe, are necessary and are the key to ending this pandemic."
Olusoga said he was also "very happy to take part" in order to help avoid a "double tragedy".
"We know from studies that there is a lower uptake of the vaccine amongst BAME (black and ethnic minority) communities and we also know that BAME communities have suffered disproportionately so I just want to help in a small way to avert what will be a double tragedy," he continued.
"There's already been a falling of this pandemic more heavily on the shoulders of minority communities."
"I hope that this campaign will make people realise that vaccinations are safe and that they are effective and that people should go and get the vaccine with confidence"@thequeenmehreen discusses how disinformation surrounding the Covid vaccine has impacted the BAME community. pic.twitter.com/ChmMyYnNXr— BBC Morning Live (@BBCMorningLive) February 18, 2021
ITV chief executive Carolyn McCall said Thursday's simultaneous broadcast would ensure the campaign's message reached "the most people at the same time".
Alex Mahon, her Channel 4 counterpart, said: "We're delighted to be able to help get this important message far and wide at such a critical time."
Sky's Stephen van Rooyen, meanwhile, said the network was "proud to be part of the biggest roadblock in television history".
BBC director general Tim Davie added: "We know there is lots of misinformation online and elsewhere. That's why the BBC will be looking at the issues raised so extensively."