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OpenTrials
Completed

NCT Number: NCT05542862

Booster Study of SpikoGen COVID-19 Vaccine

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.

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Key information

Conditions

COVID-19 Coronaviridae Infections Coronavirus Infections Infections Lung Diseases Nidovirales Infections Pneumonia Pneumonia, Viral RNA Virus Infections Respiratory Tract Diseases Respiratory Tract Infections Virus Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 3

Primary location

ARASMI

Adelaide, South Australia, 5042, Australia

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

SpikoGen vaccine

Biological

Recombinant spike protein based Covid-19 vaccine

Other names: Covax-19

Primary outcomes

  1. Seroconversion

    Time frame: Between baseline and 4 weeks post the booster dose

    Proportion of study participants who seroconvert (4-fold or greater rise in serum spike antibody) by primary vaccine group

  2. Seroprotection

    Time frame: Between baseline and 4 weeks post the booster dose

    Proportion of study participants who achieve a spike protein neutralisation titer of 32 or greater by primary vaccine group

  3. Geometric mean titer fold change

    Time frame: Between baseline and 4 weeks post the booster dose

    Increase in Geometric mean titer of spike neutralisation antibodies by primary vaccine group

  4. Safety assessment 1

    Time frame: Occurring within 7 days after booster dose.

    Frequency of Adverse events by primary vaccine group

  5. Safety assessment 2

    Time frame: Between time of administration of booster dose and through study completion, an average of 3 months

    Frequency of Serious Adverse events by primary vaccine group

  6. SARS-CoV-2 infection

    Time frame: Between time of administration of booster dose and through study completion, an average of 3 months

    Frequency of SARS-CoV-2 infections in study participants by primary vaccine group, age, gender, co-morbidities, and past infection

  7. Antibody durability

    Time frame: Between time of administration of booster dose and through study completion, an average of 3 months

    The proportion of subjects who remain seroprotected throughout the duration of the study including broken down by primary vaccine group.

  8. Seroconversion in participants with and without evidence of past infection

    Time frame: Between baseline and 4 weeks post the booster dose and through study completion, an average of 3 months

    Spike antibody seroconversion in baseline nuclear protein antibody positive versus negative participants by primary vaccine group

  9. Seroprotection in participants with and without evidence of past infection

    Time frame: Between baseline and 4 weeks post the booster dose and through study completion, an average of 3 months

    Spike antibody seroprotection in baseline nuclear protein antibody positive versus negative participants by primary vaccine group

  10. Spike antibody GMT in participants with and without evidence of past infection

    Time frame: Between baseline and 4 weeks post the booster dose and through study completion, an average of 3 months

    Spike antibody GMT in baseline nuclear protein antibody positive versus negative participants by primary vaccine group.

Secondary outcomes

  1. Antibody correlates of protection

    Time frame: Baseline and 4 weeks post the booster dose, and through study completion, an average of 3 months

    SARS-CoV-2 antibody levels in subjects with or without breakthrough SARS-CoV-2 infection

Sponsors and collaborators

Lead sponsor

Vaxine Pty Ltd

Industry

Collaborators

  • Australian Respiratory and Sleep Medicine Institute
  • Cinnagen

Registry information

Official study title

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

Important dates

Study start
2022
Primary completion
2023
Study completion
2025
First posted
Sep 16, 2022
Registry last updated
Sep 17, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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