The vaccine can now be used as a booster following the two-dose Vaxzevria schedule or by those who have been vaccinated by an mRNA vaccine, such as the ones by Pfizer and BioNTech or Moderna.
Drugmaker AstraZeneca's Covid-19 jab has won approval for use as a booster or third jab in the European Union.
"AstraZeneca's Covid-19 vaccine, Vaxzevria, has been granted approval in the EU by the EMA as a third dose booster in adults," the British drugs giant said in a statement on Monday.
"Healthcare professionals can now use Vaxzevria as a third dose booster in patients previously given a primary vaccine schedule of either Vaxzevria or an EU-approved mRNA Covid-19 vaccine," it added.
EU watchdog European Medicines Agency had revealed the news on Thursday, weeks after it backed the use of Pfizer-BioNTech's Comirnaty as a booster for adults previously inoculated with other vaccines.
The EMA had concluded there was a "substantial body of evidence demonstrating an increased immune response after a third dose booster with Vaxzevria", the company statement said.
Fight against Covid-19
AstraZeneca rapidly developed its successful Covid-19 jab alongside the University of Oxford during the pandemic.
The group announced last month that Vaxzevria sales jumped fourfold to $1.15 billion in the first quarter, despite a 40 percent decline in Europe where the pandemic has been curbed by vaccinations.
AstraZeneca also said in April that Covid revenues including Vaxzevria would drop this year as the health crisis recedes.
Several vaccine makers have indicated that most vaccinations this year will be booster shots, or first inoculations for children that are still gaining regulatory approvals globally.