The vaccine could be approved for use by the middle of next month.
The Europeans Medicines Agency has announced that pharmaceutical firm Janssen has applied for conditional authorisation for its Covid-19 vaccine.
The regulator said it had received a request for a conditional marketing authorisation which would be processed on an "accelerated timetable".
It said a decision to approve the jab developed by Johnson & Johnson, the parent company of Janssen, could be made by the middle of March.
"The EMA’s human medicines committee (CHMP) will assess the vaccine, known as Covid-19 Vaccine Janssen, under an accelerated timetable," the EMA said in a statement.
"The Committee could issue an opinion by the middle of March 2021, provided the company’s data on the vaccine’s efficacy, safety and quality are sufficiently comprehensive and robust.
"Such a short time for evaluation is only possible because EMA has already reviewed some data during a rolling review. During this phase, EMA assessed quality data and data from laboratory studies which looked at how well the vaccine triggers the production of antibodies and immune cells that target SARS-CoV-2 (the virus that causes Covid-19).
"The Agency also looked at clinical safety data on the viral vector used in the vaccine."
Approval for the vaccine depends on the agency's evaluation of the vaccine's efficacy, safety and quality.
The vaccine was shown to be 66% effective in preventing Covid-19 infections and was 100% effective in preventing hospitalisation and death, in a trial of 44,000 people.
Ireland, as part of an EU deal, is in line for roughly 2.2 million doses of the vaccine pending approval.
The Johnson & Johnson vaccine differs from the Pfizer/BioNTech, Moderna and AstraZeneca vaccines due to the fact it is a single dose vaccine, while all the other approved vaccines in the EU are two dose vaccines.
