Home
Search
Study Topics
Glossary
|
|
|
|
|
Sponsored by: |
VA Medical Center, Houston |
---|---|
Information provided by: | VA Medical Center, Houston |
ClinicalTrials.gov Identifier: | NCT00304382 |
The purpose of this study is to determine whether there are differences in the level of antibody to capsular polysaccharides of S. pneumoniae or the physiological activity of such antibody after vaccinating patients who have recovered from pneumococcal pneumonia with pneumococcal polysaccharide vaccine (Pneumovax) or conjugate pneumococcal vaccine (Prevnar).
Condition | Intervention | Phase |
---|---|---|
Pneumonia Pneumococcal Infections Infections, Streptococcus Pneumoniae |
Biological: Prevnar Biological: Pneumovax |
Phase IV |
Study Type: | Interventional |
Study Design: | Prevention, Randomized, Open Label, Uncontrolled, Crossover Assignment, Efficacy Study |
Official Title: | Humoral Determinants of Immunity to Pneumococcal Infection |
Estimated Enrollment: | 114 |
Study Start Date: | January 2003 |
Primary Completion Date: | September 2006 (Final data collection date for primary outcome measure) |
Arms | Assigned Interventions |
---|---|
PPV-PCV: Experimental
Patients receive Pneumovax, and 6 months later Prevnar
|
Biological: Prevnar
0.5 ml IM into each deltoid muscle one time (or two in group PCV-PCV)
Biological: Pneumovax
0.5 ml IM one time
|
PCV-PPV: Experimental
Patients receive Prevnar, and 6 months later Pneumovax
|
Biological: Prevnar
0.5 ml IM into each deltoid muscle one time (or two in group PCV-PCV)
Biological: Pneumovax
0.5 ml IM one time
|
PCV-PCV: Experimental
Patients receive Prevnar, and 6 months later Prevnar again
|
Biological: Prevnar
0.5 ml IM into each deltoid muscle one time (or two in group PCV-PCV)
|
PCV: Experimental
Patients receive Prevnar only
|
Biological: Prevnar
0.5 ml IM into each deltoid muscle one time (or two in group PCV-PCV)
|
Streptococcus pneumoniae (pneumococcus) is the most common cause of pneumonia leading to hospitalization of adults. Resistance to infection is generally thought to be highly associated with antibody to the capsular polysaccharide (CPS). Most people who develop pneumococcal pneumonia lack antibody to the capsule of the infecting type. We have previously shown that some persons develop this infection despite the presence of antibody to the capsular polysaccharide of the infecting type. When such antibody is found, it tends to be poorly functional (DM Musher et al, J Infect Dis 182:158-167, 2000) in that it opsonizes pneumococci poorly for phagocytosis by human white blood cells in vitro, and protects mice poorly or not at all against challenge with the infecting organism.
About 20% of patients with pneumococcal pneumonia in our previous study had been vaccinated with the only vaccine currently in use for adults, namely 23-valent pneumococcal vaccine (Pneumovax [Merck]). This product consists of purified capsular polysaccharides from 23 different serotypes of S.
pneumoniae. During the past two years, with more active vaccination programs at our hospital, the proportion of pneumococcal pneumonia patients who have been vaccinated has increased to about 60%. Clearly, the vaccine has not provided a full degree of protection.
After many years of study, including one involving nearly 40,000 children in the Kaiser Permanent health care system, a new form of pneumococcal vaccine was released. In this vaccine, Prevnar [Wyeth-Lederle], capsular polysaccharide from 7 of the most common pneumococcal types were conjugated to a protein that closely resembles diphtheria toxoid. There have been suggestions that Prevnar stimulates antibody in some subjects who fail to respond to Pneumovax (DM Musher et al, Clin Infect Dis 27:1487-1490, 1998) and also that the resulting antibody may more effectively opsonize bacteria for phagocytosis.
We propose to focus the present research on persons who develop pneumococcal pneumonia, a group that is regarded as being at very high risk of reinfection. Persons who recover from pneumococcal pneumonia will be randomized to vaccination revaccination with Pneumovax or vaccination with Prevnar.
These studies will clarify whether administration of protein conjugate pneumococcal vaccine stimulates antibody in patients with pneumonia who failed to respond to prior vaccination or stimulates better functional antibody in those who have previously responded with antibody that is only poorly functional.
Our laboratory and others have shown that Prevnar successfully immunizes adults (Ahmed et al, J Infect Dis 173:83-90, 1996). The vaccine is not officially recommended for adults because antibody levels are the same after Prevnar as after Pneumovax. Such antibody may be more functional; this has not yet been determined. Prevnar contains only 7 antigens whereas Pneumovax contains 23 antigens; thus, it would be less desirable, in general, to administer this vaccine instead of Pneumovax. However, in patients who have developed pneumonia despite having received Pneumovax, the conjugate vaccine may offer an opportunity to stimulate production of effective antibody. In the proposed research, all participants will eventually receive both Pneumovax and Prevnar.
Genders Eligible for Study: | Both |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
Exclusion Criteria:
Contact: Daniel M Musher, M.D. | 713-794-7384 | dmusher@bcm.tmc.edu |
Contact: Adriana M Rueda, M.D. | 713-794-7384 | amrueda@bcm.tmc.edu |
United States, Texas | |
Michael E. DeBakey VA Medical Center | Recruiting |
Houston, Texas, United States, 77030 | |
Contact: Daniel M Musher, M.D. 713-794-7384 | |
Contact: Adriana M Rueda 713-794-7384 | |
Principal Investigator: Daniel M Musher, M.D. | |
Sub-Investigator: Adriana M Rueda |
Principal Investigator: | Daniel M Musher, M.D. | Houston VA Medical Center |
Responsible Party: | Michael E. DeBakey VA Medical Center ( Daniel M. Musher, M.D. ) |
Study ID Numbers: | H-16562 |
Study First Received: | March 16, 2006 |
Last Updated: | February 18, 2009 |
ClinicalTrials.gov Identifier: | NCT00304382 History of Changes |
Health Authority: | United States: Institutional Review Board |
Pneumococcus Pneumococcal pneumonia |
Bacterial Infections Gram-Positive Bacterial Infections Respiratory Tract Infections Respiratory Tract Diseases Streptococcal Infections |
Lung Diseases Pneumonia, Pneumococcal Pneumococcal Infections Pneumonia |
Bacterial Infections Communicable Diseases Gram-Positive Bacterial Infections Respiratory Tract Infections Respiratory Tract Diseases |
Streptococcal Infections Lung Diseases Infection Pneumococcal Infections Pneumonia |