This study is a first-in-human (Phase 1) study using three dose levels of an investigational vaccine directed against Staphylococcus aureus (SA3Ag). This study is primarily designed to assess how safe and well tolerated SA3Ag is, but will also describe the immune response over 12 months elicited by SA3Ag. Additionally, this study will assess the effect of SA3Ag vaccine on the number of Staphylococcus aureus bacteria that naturally occur on the skin and within the nose and throat.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
TRIPLE
Enrollment
449
In stage 1, each subject will receive 1 injection (0.5 mL) of one of the following doses: Low dose level 10 μg of CP5 and CP8 and 20 μg of rClfAm Mid-dose level 30 μg of CP5 and CP8 and 60 μg of rClfAm High dose level 100 μg of CP5 and CP8 and 200 μg of rClfAm In stage 2 the subject will receive 0.5 mL IM of the same dose level he/she received in stage 1.
Blood for immunogenicity will be taken at timepoints throughout stage 1 and stage 2. Blood for hematology will be done in a select subset of subjects in stage 1.
Colonization swabs will be taken at timepoints throughout stage 1 and stage 2.
In stage 1, each subject will receive 1 injection (0.5 mL) of one of the following doses: Low dose level 10 μg of CP5 and CP8 and 20 μg of rClfAm Mid-dose level 30 μg of CP5 and CP8 and 60 μg of rClfAm High dose level 100 μg of CP5 and CP8 and 200 μg of rClfAm In stage 2 the subject will receive one injection of 0.5 mL IM of the placebo.
Blood for immunogenicity will be taken at timepoints throughout stage 1 and stage 2. Blood for hematology will be done in a select subset of subjects in stage 1.
Colonization swabs will be taken at timepoints throughout stage 1 and stage 2.
In both stage 1 and stage 2, recipients will receive one injection (0.5 mL) IM of 150 mM (isotonic) NaCl for a total of 2 injections throughout the study.
Blood for immunogenicity will be taken at timepoints throughout stage 1 and stage 2. Blood for hematology will be done in a select subset of subjects in stage 1.
Colonization swabs will be taken at timepoints throughout stage 1 and stage 2.
In stage 1, each subject will receive 1 injection (0.5 mL) of one of the following doses: Low dose level 10 μg of CP5 and CP8 and 20 μg of rClfAm Mid-dose level 30 μg of CP5 and CP8 and 60 μg of rClfAm High dose level 100 μg of CP5 and CP8 and 200 μg of rClfAm In stage 2 the subject will receive no vaccine.
Blood for immunogenicity will be taken at timepoints throughout stage 1 and stage 2. Blood for hematology will be done in a select subset of subjects in stage 1.
Colonization swabs will be taken at timepoints throughout stage 1 and stage 2.
In stage 1, recipients will receive one injection (0.5 mL) IM of 150 mM (isotonic) NaCl. In stage 2 the subject will receive no vaccine.
Blood for immunogenicity will be taken at timepoints throughout stage 1 and stage 2. Blood for hematology will be done in a select subset of subjects in stage 1.
Colonization swabs will be taken at timepoints throughout stage 1 and stage 2.
Pfizer Investigational Site
Herston, Queensland, Australia
Pfizer Investigational Site
Adelaide, South Australia, Australia
Pfizer Investigational Site
North Adelaide, South Australia, Australia
Pfizer Investigational Site
Prahran, Victoria, Australia
Pfizer Investigational Site
Subiaco, Western Australia, Australia
The primary immunogenicity endpoint in stage 1 is antigen-specific antibody levels using an Ig binding assay (Ig titers) 28 days after vaccination at visit 1 in the 50- to 85-year age stratum at each vaccine group (3 SA3Ag dose levels and placebo).
Time frame: 1 month
The primary comparison of interest is a 2-fold increase in Ig titers relative to baseline for each antigen.
Time frame: 1 month
The secondary immunogenicity endpoints are Ig titers for each antigen (CP5, CP8, and rClfAm) 28 days after vaccination in the 18- to 24-year age stratum at each dose level cohort.
Time frame: 1 month
Ig titers for each antigen 28 days after the booster dose.
Time frame: 7 months
The safety endpoints are solicited and unsolicited AEs, SAEs, and hematologic and urine parameters.
Time frame: 12 months
OPA titers for each antigen 28 days after vaccination in both age strata at selected dose level cohort(s).
Time frame: 1 month
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