@article {1433728,
	title = {Long-term comparative immunogenicity of protein conjugate and free polysaccharide pneumococcal vaccines in chronic obstructive pulmonary disease},
	journal = {Clin Infect Dis},
	volume = {55},
	number = {5},
	year = {2012},
	month = {2012 Sep},
	pages = {e35-44},
	abstract = {BACKGROUND: Although the 23-valent pneumococcal polysaccharide vaccine (PPSV23) protects against invasive disease in young healthy persons, randomized controlled trials in chronic obstructive pulmonary disease (COPD) have demonstrated no benefit in the intention-to-treat population. We previously reported that the 7-valent diphtheria-conjugated pneumococcal polysaccharide vaccine (PCV7) is safe and induced greater serotype-specific immunoglobulin G (IgG) and functional antibody than did PPSV23 1 month after vaccination. We hypothesized that these advantages would persist at 1 and 2 years.

METHODS: One hundred eighty-one patients with moderate to severe COPD were randomized to receive PPSV23 (n = 90) or PCV7 (1.0 mL; n = 91). We measured IgG by enzyme-linked immunosorbent assay and assessed functional antibody activity by a standardized opsonophagocytosis assay, reported as a killing index (OPK). We determined differences in IgG and OPK between vaccine groups at 1 and 2 years.

RESULTS: Relative to PPSV23, PCV7 induced greater OPK at both 1 and 2 years for 6 of 7 serotypes (not 19F). This response was statistically greater for 5 of 7 serotypes at 1 year and 4 of 7 at 2 years. Comparable differences in IgG were observed but were less often statistically significant. Despite meeting Centers for Disease Control and Prevention criteria for PPSV23 administration, almost 50\% of individuals had never been vaccinated. No differences in the frequency of acute exacerbations, pneumonia, or hospitalization were observed.

CONCLUSIONS: PCV7 induces a greater functional antibody response than PPSV23 in patients with COPD that persists for 2 years after vaccination. This superior functional response supports testing of conjugate vaccination in studies examining clinical end points.

CLINICAL TRIALS REGISTRATION: NCT00457977.},
	keywords = {Aged, Cohort Studies, Female, Heptavalent Pneumococcal Conjugate Vaccine, Humans, Immunoglobulin G, Male, Middle Aged, Phagocytosis, Pneumococcal Infections, Pneumococcal Vaccines, Proportional Hazards Models, Pulmonary Disease, Chronic Obstructive},
	issn = {1537-6591},
	doi = {10.1093/cid/cis513},
	author = {Dransfield, Mark T and Harnden, Sarah and Burton, Robert L and Albert, Richard K and Bailey, William C and Casaburi, Richard and Connett, John and Cooper, J Allen D and Criner, Gerard J and Curtis, Jeffrey L and Han, MeiLan K and Make, Barry and Marchetti, Nathaniel and Martinez, Fernando J and McEvoy, Charlene and Nahm, Moon H and Niewoehner, Dennis E and Porszasz, Janos and Reilly, John and Scanlon, Paul D and Scharf, Steven M and Sciurba, Frank C and Washko, George R and Woodruff, Prescott G and Lazarus, Stephen C}
}