BRUSSELS (Reuters) -The European Commission has approved a supply contract with U.S. firm Novavax to buy up to 200 million doses of its potential COVID-19 vaccine, the Commission said on Wednesday. The move is part of the EU's strategy to diversify its vaccine portfolio after the bloc betted heavily for the coming years on messenger RNA (mRNA) shots produced by Pfizer-BioNTech and Moderna. "Our new agreement with Novavax expands our vaccine portfolio to include one more protein-based vaccine, a platform showing promise in clinical trials," EU health commissioner Stella Kyriakides said in a statement. French drugmaker Sanofi, in partnership with...