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.”
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 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 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.
The three-and-a-half minute video 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”.
‘Biggest roadblock in TV history’
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.”