Spikogen Booster Study

Study Overview
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Brief Summary
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The purpose of the study is to assess the effectiveness of Spikogen vaccine when used as a 3rd or 4th dose booster in adults who have been previously vaccinated with any Covid-19 vaccine types, including mRNA vaccine, adenoviral vector vaccines, recombinant protein vaccines, or inactivated virus vaccines.

Detailed Description
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Currently in Australia, mRNA, adenoviral vector and recombinant protein vaccines have provisional approval for use as 3rd or 4th booster doses. This study will provide important data on the use of Spikogen as an alternative recombinant protein booster vaccine. The study will provide data in ambulatory adults on the safety and effectiveness of Spikogen vaccine when administered as a single intramuscular booster dose in those who previously vaccinated with mRNA vaccine in comparison to those immunised with other Covid-19 vaccine platforms.

Official Title
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Immunogenicity and Safety Study in Ambulatory Adults of a Single Intramuscular Dose of SpikoGen Vaccine as a Heterologous or Homologous Booster Dose Following Completion of a Primary Course of Covid-19 Vaccine

Conditions
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COVID-19

Intervention / Treatment
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* Biological: SpikoGen vaccine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Able to provide written informed consent Males or females 18 years of age or older Have previously had a primary course of Covid-19 vaccine with the most recent dose no less than 3 months previously. Understand and are likely to comply with planned study procedures and be available for all study visits. Exclusion Criteria Allergy to Spikogen vaccine or one of its components, e.g. polysorbate 80. Have received an experimental agent within 30 days prior to the study vaccination or expect to receive another experimental agent during the trial reporting period. Any serious medical, social or mental condition which, in the opinion of the investigator, would be detrimental to the subjects or the study.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Intervention Model: Single Group Assignment
Interventional Model Description: All subjects will receive the same single intervention with analysis groups being based on the type of primary vaccine received
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: SpikoGen vaccine<br>Single booster dose of SpikoGen Covid-19 vaccine | Biological: SpikoGen vaccine<br>* Recombinant spike protein based Covid-19 vaccine<br>* Other names: Covax-19;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Seroconversion | Proportion of study participants who seroconvert (4-fold or greater rise in serum spike antibody) by primary vaccine group | Between baseline and 4 weeks post the booster dose | 
| Seroprotection | Proportion of study participants who achieve a spike protein neutralisation titer of 32 or greater by primary vaccine group | Between baseline and 4 weeks post the booster dose | 
| Geometric mean titer fold change | Increase in Geometric mean titer of spike neutralisation antibodies by primary vaccine group | Between baseline and 4 weeks post the booster dose | 
| Safety assessment 1 | Frequency of Adverse events by primary vaccine group | Occurring within 7 days after booster dose. | 
| Safety assessment 2 | Frequency of Serious Adverse events by primary vaccine group | Between time of administration of booster dose and through study completion, an average of 3 months | 
| SARS-CoV-2 infection | Frequency of SARS-CoV-2 infections in study participants by primary vaccine group, age, gender, co-morbidities, and past infection | Between time of administration of booster dose and through study completion, an average of 3 months | 
| Antibody durability | The proportion of subjects who remain seroprotected throughout the duration of the study including broken down by primary vaccine group. | Between time of administration of booster dose and through study completion, an average of 3 months | 
| Seroconversion in participants with and without evidence of past infection | Spike antibody seroconversion in baseline nuclear protein antibody positive versus negative participants by primary vaccine group | Between baseline and 4 weeks post the booster dose and through study completion, an average of 3 months | 
| Seroprotection in participants with and without evidence of past infection | Spike antibody seroprotection in baseline nuclear protein antibody positive versus negative participants by primary vaccine group | Between baseline and 4 weeks post the booster dose and through study completion, an average of 3 months | 
| Spike antibody GMT in participants with and without evidence of past infection | Spike antibody GMT in baseline nuclear protein antibody positive versus negative participants by primary vaccine group. | Between baseline and 4 weeks post the booster dose and through study completion, an average of 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Antibody correlates of protection | SARS-CoV-2 antibody levels in subjects with or without breakthrough SARS-CoV-2 infection | Baseline and 4 weeks post the booster dose, and through study completion, an average of 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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covid-19, vaccine, adjuvant, Spikogen, Advax, CpG55.2