A randomized study comparing combined pneumococcal conjugate and polysaccharide vaccination schedules in adults.

Journal article

BACKGROUND: The widely used 23-valent plain polysaccharide vaccine (23vP) has limited effectiveness, produces short-lived immune responses, and induces attenuated antibody production after subsequent challenge with pneumococcal vaccines. Our goal was to examine whether priming with the 7-valent pneumococcal conjugate vaccine (PCV7) could enhance the immunogenicity of 23vP for the PCV7 serotypes and to investigate whether 23vP induced hyporesponsiveness could be overcome using PCV7. METHODS: We conducted an open-label randomized study that compared 3 vaccine schedules, each of which consisted of 2 doses of PCV7 and 1 dose of 23vP (23vP-PCV7-PCV7, PCV7-23vP-PCV7, PCV7-PCV7-23vP) administered over a 1-year period in a cohort of 348 adults 50-70 years of age. All vaccines were administered intramuscularly and were given 6 months apart. Blood samples were obtained prior to and 1 month after each vaccination. RESULTS: 23vP administered after priming with 2 doses of PCV7 produced significantly higher antibody concentrations for 3 of the 7 PCV7 serotypes, compared with vaccination with a single dose of 23vP; however, the same immunogenicity could be achieved with a single dose of PCV7. Prior vaccination with 23vP attenuated the antibody response to subsequent PCV7, which was not restored by additional doses of PCV7. CONCLUSION: In adults, vaccination schedules combining PCV7 and 23vP do not provide improved immunogenicity over the use of a single dose of 23vP for most of the serotypes contained in PCV7.

Authors: Lazarus, R; Clutterbuck, E; Yu, L; Bowman, J; Bateman, E

• Publication status: Published
• Journal: Clinical infectious diseases : an official publication of the Infectious Diseases Society of America
• Volume: 52
• Issue: 6
• Pages: 736-742
• Publication date: 2011-03-01
• DOI: 10.1093/cid/cir003
• EISSN: 1537-6591
• ISSN: 1058-4838
• Language: English
• Keywords: Pneumococcal Vaccines; Antibodies, Bacterial; Immunization Schedule; Immunization, Secondary; Female; Injections, Intramuscular; Vaccination; Aged; Middle Aged; Male; Humans