AstraZeneca PLC said Monday that its Covid-19 vaccine has been granted approval in the European Union as a third dose booster for adults.

The pharmaceutical company said that its Vaxzevria vaccine can now be used as a third dose booster in patients previously given a vaccine schedule of either Vaxzevria or other EU-approved vaccines.

“Although more than 65% of the global population has received at least one dose of a Covid-19 vaccine, there remains a significant challenge to ensure people receive both their primary vaccine schedule and third-dose booster, and healthcare professionals now have greater flexibility in their choice of vaccine,” AstraZeneca said.

Write to Jaime Llinares Taboada at jaime.llinares@wsj.com; @JaimeLlinaresT