Merck pits its pneumococcal shot against Pfizer's mammoth Prevnar in head-to-head ph3

Merck & Co. has a big target in mind for its pneumococcal conjugate vaccine V114: no less than Prevnar 13, the world's best-selling shot. And now, the U.S. drugmaker has put V114 a phase 3 course that includes a head-to-head trial against the Pfizer shot.