Covid-19 and Influenza Oral Vaccine Study

September 16, 2025 updated by: Vaxine Pty Ltd

A Binded, Randomised, Controlled Cross-over Trial to Assess the Safety and Efficacy of Mucosal Covid-19 and Influenza Vaccines

The purpose of the current study is to assess the effectiveness of protein-based COVID-19 or influenza vaccines when given individually or together via oral/ sublingual mucosal route instead of intramuscular delivery. The comparator will be a seasonal influenza vaccine which will also be administered with Advax-CpG adjuvant via the oral route. This study will use a cross-over design and everyone in the study will over a space of about 4 months receive both the COVID-19 and influenza vaccines.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The SARS-CoV-2 outbreak has caused millions of deaths globally. It has a particularly high mortality rate in elderly people and those with chronic disease. SARS-COV-2 vaccines remain a key priority to help fight the current pandemic as they help reduce symptomatic infection and disease severity. However, vaccine immunity starts to wane as early as 3 months following the most recent immunisation. This rapidly waning vaccine immunity is a particular problem for the newer Omicron variants. Spikogen® vaccine is an Advax-CpG55.2 adjuvanted recombinant protein vaccine that was shown to significantly reduce infection and serious disease in a pivotal Phase 3 trial in 16,876 participants who received two intramuscular doses 3 weeks apart. SpikoGen® vaccine was licensed for use in the Middle East as a primary vaccine course in adults in October 2021. Eight million doses of SpikoGen® vaccine have subsequently been supplied to date. A booster study confirmed the safety and immunogenicity of SpikoGen® vaccine when given as a third dose intramuscular booster to adult participants who previously received two doses of either inactivated viral vaccine, adenoviral vector vaccine, mRNA or recombinant protein vaccine. While COVID-19 vaccines such as SpikoGen® vaccine have been shown to reduce the incidence of severe SARS-CoV-2 infection disease, they have less effect on SARS-CoV-2 infection or transmission. This is because intramuscular vaccines largely work by increasing antibody and T cell levels within the body, whereas what is needed to prevent infection and transmission is mucosal immunity, which means increasing immunity at the body surfaces where the virus initially gets access to the body, namely the mucosal surfaces of the nose and upper respiratory tract. To induce mucosal immunity normally requires immune cells at these respiratory tract surfaces to be exposed to the relevant viral antigen, which requires the vaccine to be applied to these surfaces in such a way as to trigger an appropriate immune response.The current study is based on the finding that an adjuvanted protein-based COVID-19 vaccine (SpikoGen®) when given as 2 sublingual doses 2 weeks apart in monkeys that had previously received a primary course of 2 intramuscular doses of the same vaccine, was safe and well tolerated and induced robust protection against challenge with the heterologous Omicron BA.5 virus. The monkeys that received the sublingual boost also showed reduced nasal virus shedding (additional details in the Investigator Brochure). This suggests an oral/ sublingual COVID-19 vaccine may also help block virus transmission. Similarly, mice that received sublingual inactivated influenza vaccine with Advax-CpG adjuvant have demonstrated robust protection against an otherwise lethal influenza infection. The purpose of the current study is to assess the effectiveness of protein-based COVID-19 or influenza vaccines when given individually or together via oral/ sublingual mucosal route instead of intramuscular delivery. The comparator will be a seasonal influenza vaccine which will also be administered with Advax-CpG adjuvant via the oral route. This study will use a cross-over design and everyone in the study will over a space of about 4 months receive both the COVID-19 and influenza vaccines.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
100

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Australia
    • South Australia
      • Adelaide, South Australia, Australia, 5042
        • Recruiting
        • ARASMI
        • Contact:
        • Principal Investigator:
          • Dimitar Sajkov, MBBS

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Able to provide written informed consent
  • Males or females 18 years of age or older
  • Understand and are likely to comply with planned study procedures and be available for all study visits.
  • Do not plan to have a non-study COVID-19 or influenza vaccine within the next 6 months.

Exclusion Criteria:

  • Allergy to COVID-19 or seasonal influenza vaccine or one of its components e.g. polysorbate 80.
  • Have received a COVID-19 or influenza vaccine or an experimental agent within 30 days prior to the study vaccination or expect to receive another experimental agent or a COVID-19 or influenza vaccine 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.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Covid-19 vaccine group
Subjects in this group will receive two sublingual doses of COVID-19 vaccine two weeks apart. Three months after the second dose they will receive two sublingual doses of influenza vaccine two weeks apart.
Biological: Covid-19 vaccine
Recombinant SARS-CoV-2 spike protein with Advax-CpG55.2 adjuvant
Other Names:
  • SARS-CoV-2 vaccine
Biological: Influenza vaccine
Inactivated seasonal influenza vaccine with Advax-CpG55.2 adjuvant
Experimental: Influenza vaccine group
Subjects in this group will receive two sublingual doses of influenza vaccine two weeks apart. Three months after the second dose they will receive two sublingual doses of COVID-19 vaccine two weeks apart.
Biological: Covid-19 vaccine
Recombinant SARS-CoV-2 spike protein with Advax-CpG55.2 adjuvant
Other Names:
  • SARS-CoV-2 vaccine
Biological: Influenza vaccine
Inactivated seasonal influenza vaccine with Advax-CpG55.2 adjuvant
Experimental: Combined vaccine group
Subjects in this group will receive two sublingual doses of combined COVID-19 and influenza vaccine two weeks apart. Three months after the second dose they will receive two sublingual doses of placebo vaccine two weeks apart.
Biological: Covid-19 vaccine
Recombinant SARS-CoV-2 spike protein with Advax-CpG55.2 adjuvant
Other Names:
  • SARS-CoV-2 vaccine
Biological: Influenza vaccine
Inactivated seasonal influenza vaccine with Advax-CpG55.2 adjuvant

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
SARS-CoV-2 Seroconversion
Time Frame: Between baseline and 2 weeks post the second dose
Proportion of study participants who seroconvert (4-fold or greater rise in serum spike antibody) by primary vaccine group
Between baseline and 2 weeks post the second dose
Influenza Seroconversion
Time Frame: Between baseline and 2 weeks post the second dose
Proportion of study participants who seroconvert (4-fold or greater rise in hemagglutinin antibody) by primary vaccine group
Between baseline and 2 weeks post the second dose
SARS-CoV-2 Seroprotection
Time Frame: Between baseline and 2 weeks post the second dose
Proportion of study participants who achieve a spike protein neutralisation titer of 32 or greater by primary vaccine group
Between baseline and 2 weeks post the second dose
Influenza Seroprotection
Time Frame: Between baseline and 2 weeks post the second dose
Proportion of study participants who achieve a hemagglutinin neutralisation titer of 40 or greater by primary vaccine group
Between baseline and 2 weeks post the second dose
SARS-CoV-2 Geometric mean titer fold change
Time Frame: Between baseline and 2 weeks post the second dose
Increase in Geometric mean titer of spike neutralisation antibodies by primary vaccine group
Between baseline and 2 weeks post the second dose
Influenza geometric mean titer fold change
Time Frame: Between baseline and 2 weeks post the second dose
Increase in Geometric mean titer of spike neutralisation antibodies by primary vaccine group
Between baseline and 2 weeks post the second dose
Safety assessment 1
Time Frame: Between time of administration of first dose and through study completion, an average of 10 months
Frequency of Adverse events by primary vaccine group
Between time of administration of first dose and through study completion, an average of 10 months
Safety assessment 2
Time Frame: Between time of administration of first dose and through study completion, an average of 10 months
Frequency of Serious Adverse events by primary vaccine group
Between time of administration of first dose and through study completion, an average of 10 months
SARS-CoV-2 infection
Time Frame: From 2 weeks post the administration of the second dose and through study completion, an average of 10 months
Frequency of SARS-CoV-2 infections in study participants by primary vaccine group, age, gender, co-morbidities, and past infection
From 2 weeks post the administration of the second dose and through study completion, an average of 10 months
Influenza infection
Time Frame: From 2 weeks post the administration of the second dose and through study completion, an average of 10 months
Frequency ofinfluenza infections in study participants by primary vaccine group, age, gender, co-morbidities, and past infection
From 2 weeks post the administration of the second dose and through study completion, an average of 10 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Antibody durability
Time Frame: From 2 weeks post the administration of the second dose and through study completion, an average of 10 months
The proportion of subjects who remain seroprotected throughout the duration of the study including broken down by primary vaccine group.
From 2 weeks post the administration of the second dose and through study completion, an average of 10 months
Seroconversion in participants with and without evidence of past infection
Time Frame: From 2 weeks post the administration of the second dose and through study completion, an average of 10 months
Antibody seroconversion in participants by primary vaccine group
From 2 weeks post the administration of the second dose and through study completion, an average of 10 months
Antibody GMT in participants with and without evidence of past infection
Time Frame: From 2 weeks post the administration of the second dose and through study completion, an average of 10 months
Antibody GMT in baseline seropositive versus negative participants by primary vaccine group.
From 2 weeks post the administration of the second dose and through study completion, an average of 10 months
Antibody correlates of protection
Time Frame: From 2 weeks post the administration of the second dose and through study completion, an average of 10 months
antibody levels in subjects with or without breakthrough infection
From 2 weeks post the administration of the second dose and through study completion, an average of 10 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Vaxine Pty Ltd

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Australian Respiratory and Sleep Medicine Institute Ltd

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Dimitar Sajkov, MBBS/PhD, ARASMI

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 1, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2025

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 7, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 7, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 9, 2024

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 17, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 16, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • Vaxine-2301

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

There is no plan to share IPD with external researchers

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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