GVGH Shigella Sonnei 1970GAHB is a vaccine aimed at preventing the disease caused by Shigella sonnei. A post-hoc analysis of subjects who participated in the parent study showed significantly different responses in subjects with detectable versus undetectable antibody titres at baseline, suggesting the possibility that the vaccine might not be sufficiently immunogenic in completely naïve adults. This study was then designed to further characterize the immunogenicity profile of the vaccine and to evaluate whether it was able to induce an immunological memory response.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
PREVENTION
Masking
NONE
Enrollment
35
Single dose administered at Day 1, by intramuscular injection.
GSK Investigational Site
Paris, France
Concentrations of Immunoglobulin (IgG) Against Lipopolysaccharide (LPS) S. Sonnei O-antigen
IgG concentrations are expressed as Geometric Mean Concentrations (GMCs), as determined by the Enzyme-linked immunosorbent assay (ELISA) with Shigella sonnei (S.sonnei) O-antigen containing Lipopolysaccharide (LPS) coating antigen. Concentrations are presented as GMCs expressed in ELISA units per milliliter (EU/mL).
Time frame: At Day 8 (7 days after vaccination)
Number of Subjects With Abnormal Haematological Test Values
Assessed haematological parameters are: basophils (BAS), eosinophils (EOS), erythrocytes (ERCS), hematocrit (HCT), hemoglobin (HGB), leukocytes (LKCS), lymphocytes (LYM), monocytes (MONO), neutrophils (NEU) and platelet (PLT).
Time frame: At Day 8 (7 days after vaccination) and Day 85 (84 days after vaccination)
Number of Subjects With Solicited Local Adverse Events
Assessed solicited local adverse events include injection site erythema, injection site induration and injection site pain. Any symptom = occurrence of the symptom regardless of intensity grade.
Time frame: From 30 minutes through Day 7 post-vaccination
Number of Subjects With Solicited Systemic Adverse Events
Assessed solicited systemic adverse events include arthralgia, chills, fatigue, headache, malaise, myalgia and oral fever. Other indicators of solicited adverse events include prevention of pain and/or fever and treatment of pain and/or fever. Any symptom = occurrence of the symptom regardless of intensity grade. Fever = body temperature (measured orally) equal to or above (≥) 38.0 °C.
Time frame: From 30 minutes through Day 7 post-vaccination
Number of Subjects With Unsolicited Adverse Events
An unsolicited adverse event (AE) is an adverse event that was not solicited using a Subject Diary and that was spontaneously communicated by a subject who has signed the informed consent. Potential unsolicited AEs may be medically attended (defined as symptoms or illnesses requiring hospitalization, or emergency room visit, or visit to/by a health care provider), or were of concern to the subject. Any = occurrence of the symptom regardless of intensity grade. Grade 3 AE = AE that prevented daily activity. Possibly/probably related AE = AE determined by the investigator as possibly related (the administration of the investigational vaccine and AE are considered reasonably related in time and the AE could be explained by exposure to the investigational vaccine or by other causes) or probably related (exposure to the investigational vaccine and AE are reasonably related in time and no alternative explanation has been identified) to the study vaccination.
Time frame: Throughout the study period (From Day 1 up to Day 85)
Number of Subjects With Serious Adverse Events (SAEs)
A serious adverse event is defined as an untoward medical occurrence that at any dose resulted in death, was life-threatening, required hospitalization or prolonged hospitalization, resulted in persistent or significant disability/incapacity, or in a congenital anomaly/birth defect; an important and significant medical event that may not be immediately life-threatening or resulting in death or hospitalization but, based upon appropriate medical judgment, may jeopardize the subject or may require intervention to prevent one of the other outcomes listed above.
Time frame: Throughout the study period (from Day 1 up to Day 85)
Concentrations of IgG Against LPS S. Sonnei O-antigen
Concentrations of IgG against S.sonnei O-antigen are presented as GMCs, expressed in ELISA units per milliliter (EU/mL).
Time frame: At Days 15, 29 and 85 (14, 28 and 84 days after vaccination)
Anti-LPS S. Sonnei IgG Geometric Mean Ratios
Within-subject Geometric mean ratios (GMRs) were computed for GMCs at 7, 14, 28 and 84 days after vaccination versus baseline (Day 1). The GMRs and 95% confidence intervals (CIs) were constructed by exponentiating the mean within-subject differences in log-transformed concentrations and the corresponding 95% CIs.
Time frame: At Days 8, 15, 29 and 85 (7, 14, 28 and 84 days after vaccination)
Percentage of Subjects With Seroresponse for Anti-LPS S. Sonnei
Seroresponse is aimed to define a significant increase in post-vaccination samples based on the biological performance of this specific serology assay and it is defined as follows: - If the baseline value is greater than 50 ELISA Units (EU) then an increase of at least 50% in the post-vaccination sample as compared to baseline \[i.e. ((Post-vac minus baseline)/baseline)100% ≥ 50%\]. - If the baseline value is less or equal to 50 EU then an increase of at least 25 EU in the post-vaccination sample as compared to baseline \[i.e. (Postvac minus baseline) ≥ 25 EU.
Time frame: At Days 8, 15, 29 and 85 (7, 14, 28 and 84 days after vaccination)
Percentage of Subjects With Anti-LPS S. Sonnei Concentrations Equal to or Above (≥) 121 EU/mL
Anti-LPS S.sonnei antibody concentrations were assessed by ELISA. The assay cut-off value was 121 EU/mL.
Time frame: At Days 8, 15, 29 and 85 (7, 14, 28 and 84 days after vaccination)
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