Sixty million doses of the Novavax coronavirus vaccine will be produced on Teesside if approval is given by the UK's medicine regulator.
The manufacturer has submitted final data on the vaccine to the Medicine and Healthcare products Regulatory Authority (MHRA) - and anticipates a "positive decision".
If successful, it would mean up to 60 million doses of the vaccine Britain has ordered would be produced by Fujifilm in Billingham.
Stanley Erck, Novavax president, said: "This submission brings Novavax significantly closer to delivering millions of doses of the first protein-based Covid-19 vaccine, built on a proven, well-understood vaccine platform that demonstrated high efficacy against multiple strains of the coronavirus."
According to the results of a phase three trial, announced in March, the jab offers 100% protection against severe disease, including all hospital admission and death.
Results released in January by Novavax on a South Africa trial showed 60% protection against mild, moderate or severe disease, where most cases were the South African variant.
Analysis by ITV News Tyne Tees health correspondent Helen Ford
This news follows a period of uncertainty for those with an interest in the Novavax COVID vaccine.
In autumn 2020, more than five hundred people in the North East joined trials of the vaccine, with fifteen thousand participants around the country.
It was widely anticipated that Novavax would complete its application for regulatory approval earlier this year. As time went on, a number of trial participants came forward to say they felt in 'limbo'. For example, with the vaccine largely unrecognised outside the UK, some said they were unable to travel abroad.
There were also concerns about the ability of volunteers to receive a 'booster' jab this autumn. Those issues were addressed earlier this month when it was announced that trial volunteers would be offered additional doses of approved vaccines.
The filing of final submissions by Novavax is also an important development in Billingham where Fujifilm Diosynth is due to manufacture millions of doses of the vaccine. It told me it's 'delighted' that Novavax has reached this 'significant milestone'. It's a view echoed by the area's MP, Alex Cunningham, who had been in contact with Novavax just days ago.
It is also important to remembering that earlier this year, it was announced that Glaxo SmithKlein in Barnard Castle would be involved in the final stages of the manufacturing process, preparing vials of the vaccine and packing them for distribution.
There is currently no indication on how long the next stage of this process will take, but attention now moves to the medicines regulator - the MHRA - for its decision.
'Huge step forward'
Stockton North MP Alex Cunningham met with Novavax’s head of government affairs on Tuesday.
Welcoming the latest milestone, he said he did not know how long the process would take but hoped production would be up and running "soon".
He added: “This announcement is good for Billingham – creating jobs for the area – and also good for our continuing efforts to protect people against coronavirus.
"We now need it approved, produced and ready to be administered to people as soon as practically possible – and I‘ll continue to monitor Novavax’s progress.”
And Tees Valley Mayor Ben Houchen said the submission was a "major step forward", adding: "The Novavax vaccine will be another weapon in our armoury against the coronavirus and I’m proud it will be produced in Fujifilm Diosynth’s world-class manufacturing here and the Teesside."
Earlier this month, it was announced thousands of people who took part in the trial will be able to have two further doses of another vaccine to enable them to travel abroad.
The fact the jab has not yet been approved means thousands of people have been unable to travel because other countries do not recognise Novavax as a valid covid vaccine.
The Department of Health said those in England who took part in the UK-based Novavax trial should be offered two doses of the Pfizer/BioNTech jab, with eight weeks between the doses.
More coronavirus vaccine news from ITV News Tyne Tees