Johnson & Johnson's single dose COVID-19 vaccine will first be delivered in European countries on April 19..
The vaccine was the fourth to be approved by the European Medicines Agency after the Pfizer-BioNTech, Moderna and AstraZeneca vaccines.
It is already being administered in the United States and South Africa.
The EU's agreement with the company is for 200 million doses which Johnson & Johnson has committed to deliver in 2021.
The Commission has said that 55 million doses are expected from the company by the end of June 2021 but the exact schedule of deliveries has not been made public.
The American laboratory has several agreements with laboratories and subcontractors in Europe that will be responsible for manufacturing and bottling the vaccine.
The active substance, which gives the vaccine its effectiveness, will come from the Johnson & Johnson site in Leiden in the Netherlands.
The Johnson & Johnson vaccine is based on an adenovirus viral vector that has been modified to contain the gene for the coronavirus' spike protein. The vector passes the gene into a person's cells which then produce the spike protein.
The immune system then produces antibodies to target the spike protein and recognise it in the future.
The vaccine was shown to be 67% effective at reducing the number of symptomatic COVID-19 cases.
The European Medicines Agency granted the company a conditional marketing authorisation in mid-March, stating that it met the "criteria for efficacy, safety and quality".