Pfizer’s (NSE:PFE) pneumococcal 13-valent conjugate vaccine Prevnar 13 is one of pharma’s bestsellers, earning nearly $6 billion last year. Now, the company has scored FDA approval for its Prevnar 20 vaccine for adults 18 and older. The vaccine is the first to offer protection against 20 serotypes of pneumococcal disease that cause the majority of pneumonia and…

Pfizer’s (NSE:PFE) pneumococcal 13-valent conjugate vaccine Prevnar 13 brought in $5.85 billion last year, but Merck (NYSE:MRK) is hoping to increase its presence in the market with its investigational 15-valent pneumococcal conjugate vaccine. Although Merck has a pneumococcal vaccine on the market known as Pneumovax 23, its sales were $1.1 billion last year. While technically a…