Declining invasive pneumococcal disease in the U.S. elderly.

In 2000, pneumococcal conjugate vaccine (PCV7) was recommended for young children. By 2002-2003, 48.6% had been fully immunized. Using Medicare administrative, we found that the rates of invasive pneumococcal disease (IPD) hospitalizations in the elderly in the 2000-2001, 2001-2002 and 2002-2003, were 22.6, 30.2, and 40.6% lower, respectively, than during the baseline period, 1996-1997 through 1999-2000 (range 35.1/100,000 to 38.3/100,000). Pneumococcal polysaccharide vaccine (PPV23) has been recommended for the elderly, since 1989. PPV23 vaccination rates in the elderly increased by 25.2% during the baseline period but by <5% during the period PCV7 has been available. Thus, during the period that PCV7 vaccine has been used in children, rates of IPD in the elderly have declined appreciably more compared to the immediately prior period when PPV23 was the only vaccine available.