Rival drugmakers are seeking to upend Pfizer Inc.’s dominance of the $7 billion worldwide market for pneumonia vaccines, launching what is shaping up to be one of the industry’s fiercest battles.
Merck & Co. has already introduced a new competitor to Pfizer’s Prevnar vaccine franchise, while GSK PLC and Vaxcyte Inc. are among companies developing shots that aim to win sales by protecting against even more strains of the pneumonia virus.
