BRUSSELS (AP) — The European Commission has secured an agreement with Pfizer-BioNTech for an extra 4 million doses of COVID-19 vaccines to tackle a surge of coronavirus clusters that have prompted border restrictions. The doses are expected to be delivered before the end of March. The EU’s executive arm is worried by the worsening situation in several areas, mainly due to the spread of new variants. It also does not want virus clusters to prompt more border restrictions. The EU has cited Tyrol in Austria, Nice and Moselle in France, Bolzano in Italy and some parts of Bavaria and Saxony in Germany as places where COVID-19 hospitalizations have been on the rise.