BRUSSELS, July 18 (Reuters) - The European Commission said on Monday it has secured about 54,000 additional doses of the monkeypox vaccine developed by biotech firm Bavarian Nordic as concern mounts over the disease amid a spike in cases.

The supply deal follows an initial contract signed in June, when the European Union ordered about 110,000 doses of Bavarian Nordic's vaccine.

"I am concerned by the increasing number of monkeypox cases in the EU," EU health commissioner Stella Kyriakides said, adding that there were now over 7,000 cases reported in the EU, marking a nearly 50% increase from last week.

Under the initial order, the EU has so far delivered around 25,000 doses to six member states, the Commission said in a statement.

Vaccines are delivered prioritising countries on the basis of needs and the number of cases.

Norway and Iceland are also entitled to receive monkeypox vaccines, in addition to the 27 EU states. (Reporting by Francesco Guarascio; editing by Catherine Evans and Mark Heinrich)