Merck gets shot in the arm with FDA approval for first pneumococcal vaccine designed for adults FiercePharmaFDA approves Merck vaccine designed to protect adults from bacteria that can cause pneumonia, serious infections 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 Bloomberg