The U.S.

FDA on Thursday approved an expanded indication for Merck & Co Inc.'s (NYSE:MRK) Capvaxive, extending its use to children and adolescents ages 2–17 with chronic conditions who have completed a primary pneumococcal vaccine series.

The decision makes Capvaxive the only pneumococcal conjugate vaccine specifically studied and indicated in the U.S. for this patient group.

Phase 3 STRIDE-13 data helped win approval.

The data evaluated Capvaxive against PPSV23 in pediatric and adolescent patients at elevated risk of pneumococcal disease due to underlying medical conditions.