In 2008, ACIP reviewed evidence indicating that asthma is an independent risk factor for pneumococcal disease among adults. ACIP also reviewed evidence demonstrating an increased risk of invasive pneumococcal disease among smokers. Consequently, ACIP includes both asthma and cigarette smoking as indications for pneumococcal vaccination among adults age 19 through 64 years. People with these conditions should receive either a single dose of PCV20 alone, or a dose of PCV15 followed one year later by PPSV23. If they have already received PPSV23, but have not had a conjugate vaccine, they should receive either a single dose of PCV20 or a single dose of PCV15 at least one year following their dose of PPSV23.