Pneumococcal disease is blamed for more than 16,000 adult deaths in the United States each year, but experts say existing vaccines do little to alleviate what has become a $1 billion-a-year public health burden. CDC guidelines recommend a dose of pneumococcal protein-polysaccharide conjugate vaccine (PCV13) followed by a dose of pneumococcal polysaccharide vaccine (PPV23) for older adults as well as adults of any age who are immunocompromised. The vaccines have only limited effectiveness in adults, however, considering that PCV13 offers minimal protection against the non-bacteremic pneumococcal pneumonia that tends to afflict adults and PPV23 offers none. Yale University's Daniel M. Weinberger and Eugene D. Shapiro, along with Zitta B. Harboe of Denmark's Statens Serum Institut, urge the development of a new conjugate vaccine meant for exclusive use by older adults and immunocompromised adults. The formulation would differ from that currently used in vaccines that target the pediatric population, training specifically on serotypes that most commonly cause pneumococcal disease in older generations. The biggest obstacles, according to the authors, are selecting serotypes for the vaccine, getting regulatory and industry watchdogs on board, and demonstrating to manufacturers that they can expect to make a reasonable profit.