Asthma
Conditions
Keywords
preschool asthma, sequential pneumococcal immunization, immunogenicity, safety
Brief summary
Asthma is a major health problem in preschool children. Infections by pneumococci a the most frequent cause of airway infections, which tend to cause worsening of asthma. Vaccination against pneumococci is recommended by scientific boards and the medical community, in order to reduce the burden of disease. Data on the immunogenicity and safety of pneumococcal immunization in preschool asthmatics are scarce.
Detailed description
Respiratory infections are major triggers of exacerbations in preschool asthma. Many countries' guidelines recommend immunization against pneumococci for patients suffering from chronic airway disease. Also the interval between priming and booster is a matter of debate. We immunize a large group of preschool asthmatics (2-5 years old) sequentially: one dose of seven-valent pneumococcal conjugate vaccine (PCV-7) followed by a single dose of 23-valent pneumococcal polysaccharide vaccine (PPV-23). We randomly assign half of the vaccinees to receive PPV-23 eight weeks after PCV-7 (group A), and the rest to a 10-month interval (group B). Pneumococcal antibody concentrations to serotype 4, 5, 6B, 7, 9V, 14, 18c, 19F, and 23F are determined initially, after two, and 12 months after PCV-7. Local and systemic reactions to each vaccine are recorded.
Interventions
Sponsors
Johann Wolfgang Goethe University Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
2 Years to 5 Years
Healthy volunteers
No
Inclusion criteria
* asthma classified according to the Global Initiative on Asthma (GINA) °1-2
Exclusion criteria
* antecedent pneumococcal immunization
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Immunogenicity of Pneumococcal Vaccination | 12 months | we performed pneumococcal serotype specific ELISA according to WHO's criteria for protective threshold values (\>0.35 µg/ml). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Number of Vaccinees With Adverse Events | 12 months | we evaluated the safety and tolerability of sequential pneumococcal immunization as to local and systemic adverse events. |
Participant flow
Recruitment details
11/2005-09/07: 70 outpatients (2-5-yo)with \>3 asthma episodes during 12 months. Exclusion: pneumococcal immunization,severe/unstable asthma, systemic steroids, preterm birth (\<37 weeks of gestation), low birthweight (\<2500 g), major congenital abnormalities, and known intolerance towards ingredients of the pneumococcal vaccines.
Participants by arm
| Arm | Count |
|---|---|
| Group A Pneumococcal Immunization (2 mo) one dose of pneumococcal conjugate vaccine followed after 2 months by one dose of pneumococcal polysaccharide vaccine | 36 |
| Group B Pneumococcal Immunization (10 mo) one dose of pneumococcal conjugate vaccine followed after 10 months by one dose of pneumococcal polysaccharide vaccine | 34 |
| Total | 70 |
Baseline characteristics
| Characteristic | Group B Pneumococcal Immunization (10 mo) | Group A Pneumococcal Immunization (2 mo) | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 34 Participants | 36 Participants | 70 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 0 Participants | 0 Participants | 0 Participants |
| Age Continuous | 3 years STANDARD_DEVIATION 0.7 | 3 years STANDARD_DEVIATION 0.5 | 3 years STANDARD_DEVIATION 0.6 |
| Region of Enrollment Germany | 34 participants | 36 participants | 70 participants |
| Sex: Female, Male Female | 16 Participants | 15 Participants | 31 Participants |
| Sex: Female, Male Male | 18 Participants | 21 Participants | 39 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 0 / 0 |
| serious Total, serious adverse events | 0 / 0 |
Outcome results
Primary
Immunogenicity of Pneumococcal Vaccination
we performed pneumococcal serotype specific ELISA according to WHO's criteria for protective threshold values (\>0.35 µg/ml).
Time frame: 12 months
Population: we performed a power calculation in advance. To demonstrate a difference wit p\<0.05, we would require 30 subjects per arm each. Thus and to allow potential drop-outs, we included 35 subjects per arm.
| Arm | Measure | Value (GEOMETRIC_MEAN) |
|---|---|---|
| Group A Pneumococcal Immunization (2 mo) | Immunogenicity of Pneumococcal Vaccination | 0.05 [µg/ml] |
| Group B Pneumococcal Immunization (10 mo) | Immunogenicity of Pneumococcal Vaccination | 0.05 [µg/ml] |
Secondary
Number of Vaccinees With Adverse Events
we evaluated the safety and tolerability of sequential pneumococcal immunization as to local and systemic adverse events.
Time frame: 12 months
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Group A Pneumococcal Immunization (2 mo) | Number of Vaccinees With Adverse Events | 0 participants |
| Group B Pneumococcal Immunization (10 mo) | Number of Vaccinees With Adverse Events | 0 participants |