BRUSSELS - Cases of Omicron BA2, a COVID-19 subvariant, are rising across the European Union (EU), the European Medicines Agency (EMA) said on Thursday.

"While many EU countries are lifting restrictions, we notice that the infection rates are increasing again in some member states, partly because of the circulation of Omicron BA2, which seems to be more transmissible than other variants," Marco Cavalieri, head of the EMA's strategy on biological health threats and vaccines, told journalists here.

What matters the most, he said, is how this increase in cases will stress the healthcare systems.

The EMA called non-vaccinated citizens to get jabbed as soon as possible, emphasizing that there are now five COVID-19 vaccines authorized in the EU using different technologies.

"There is currently no evidence that immune response after vaccination is significantly different with Omicron BA2. Vaccines continue to offer high protection against hospitalization and death," he said.

The vaccines that have received conditional marketing authorization from the EMA are those produced by Pfizer/BioNtech, Moderna, AstraZeneca, Janssen and Novavax.