NEW YORK (AP) ¿ Pfizer Inc. said Friday European regulators have approved a new version of its children's pneumococcal vaccine, Prevenar 13. The vaccine is approved for children aged 6 weeks to 5 years to prevent pneumococcal disease, as well as pneumonia and middle ear infections caused by related strains of the bacterium. Pneumococcal disease can also cause meningitis and blood infections. The European Commission's approval was based on late-stage clinical studies of more than 7,000 children that showed the drug's safety and effectiveness, Pfizer said in a statement. The drug was developed by Wyeth. New York-based Pfizer, the world's largest drugmaker, bought Wyeth for $68 billion in a deal completed earlier this year. Wyeth said in September that European Union regulators had recommended approval of Prevenar 13. The original vaccine, Prevenar, was Wyeth's second best-selling drug, with $2.7 billion in revenue in 2008 as the world's best-selling vaccine. The original version blocks seven strains of pneumococcal bacteria. The new version blocks a total of 13 strains. The vaccine is still being reviewed by the U.S. Food and Drug Administration.