FDA approves Merck pneumococcal disease vaccine designed for adults CNBCMerck’s vaccine approval poses threat to one of Pfizer’s top-selling products MarketWatchNew Merck pneumococcal vaccine wins FDA approval STATMerck Wins US Approval for Pneumonia Vaccine to Rival Pfizer’s BloombergMerck gets shot in the arm with FDA approval for first pneumococcal vaccine designed for adults FiercePharma