Related Experiment Video
Updated: Jun 4, 2026

Experimental Human Pneumococcal Carriage
Published on: February 15, 2013
A randomized study comparing combined pneumococcal conjugate and polysaccharide vaccination schedules in adults
Rajeka Lazarus1, Elizabeth Clutterbuck, Ly-Mee Yu
1Oxford Vaccine Group, University of Oxford, Oxford, UK. rajeka.lazarus@doctors.net.uk
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.
Related Concept Videos
Bioavailability Study Design: Single Versus Multiple Dose Studies
Vaccinations
Bioavailability Study Design: Healthy Subjects Versus Patients
Pneumonia V: Nursing management and Prevention
The nurse must practice strict medical asepsis and adhere to infection control guidelines to minimize healthcare-associated infections.
Enhance airway patency
Position the patient correctly to facilitate drainage of the affected lung segments. Manual or mechanical percussion and vibration can also be employed.
Dosage Regimens: Designs and Approaches
Streptococcal Pharyngitis

