Booster Study of SpikoGen COVID-19 Vaccine

NCT05542862 | Completed Phase 3 DMC

• 1 other identifier: AUST-C19-booster
• Study Type: interventional
• Target: 81
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

COVID-19

Keywords

covid-19; vaccine; adjuvant; Spikogen; Advax; CpG55.2

Outcome Measures

Primary Outcomes (10)

• 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 Outcomes (1)

• Antibody correlates of protection

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

Study Arms (1)

SpikoGen vaccine

EXPERIMENTAL

Single booster dose of SpikoGen Covid-19 vaccine

Biological: SpikoGen vaccine

Interventions

SpikoGen vaccine BIOLOGICAL

Recombinant spike protein based Covid-19 vaccine

Also known as: Covax-19

SpikoGen vaccine

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Vaxine Pty Ltd: lead
• Australian Respiratory and Sleep Medicine Institute Ltd: collaborator
• Cinnagen: collaborator

Study Sites (1)

ARASMI

Adelaide, South Australia, 5042, Australia

Location

Related Publications (6)

• Tabarsi P, Anjidani N, Shahpari R, Mardani M, Sabzvari A, Yazdani B, Roshanzamir K, Bayatani B, Taheri A, Petrovsky N, Li L, Barati S. Safety and immunogenicity of SpikoGen(R), an Advax-CpG55.2-adjuvanted SARS-CoV-2 spike protein vaccine: a phase 2 randomized placebo-controlled trial in both seropositive and seronegative populations. Clin Microbiol Infect. 2022 Sep;28(9):1263-1271. doi: 10.1016/j.cmi.2022.04.004. Epub 2022 Apr 15.

  PMID: 35436611 BACKGROUND

• Tabarsi P, Anjidani N, Shahpari R, Roshanzamir K, Fallah N, Andre G, Petrovsky N, Barati S. Immunogenicity and safety of SpikoGen(R), an adjuvanted recombinant SARS-CoV-2 spike protein vaccine as a homologous and heterologous booster vaccination: A randomized placebo-controlled trial. Immunology. 2022 Nov;167(3):340-353. doi: 10.1111/imm.13540. Epub 2022 Jul 13.

  PMID: 35758850 BACKGROUND

• Li L, Honda-Okubo Y, Baldwin J, Bowen R, Bielefeldt-Ohmann H, Petrovsky N. Covax-19/Spikogen(R) vaccine based on recombinant spike protein extracellular domain with Advax-CpG55.2 adjuvant provides single dose protection against SARS-CoV-2 infection in hamsters. Vaccine. 2022 May 20;40(23):3182-3192. doi: 10.1016/j.vaccine.2022.04.041. Epub 2022 Apr 18.

  PMID: 35465982 BACKGROUND

• Li L, Honda-Okubo Y, Huang Y, Jang H, Carlock MA, Baldwin J, Piplani S, Bebin-Blackwell AG, Forgacs D, Sakamoto K, Stella A, Turville S, Chataway T, Colella A, Triccas J, Ross TM, Petrovsky N. Immunisation of ferrets and mice with recombinant SARS-CoV-2 spike protein formulated with Advax-SM adjuvant protects against COVID-19 infection. Vaccine. 2021 Sep 24;39(40):5940-5953. doi: 10.1016/j.vaccine.2021.07.087. Epub 2021 Aug 3.

  PMID: 34420786 BACKGROUND

• Tabarsi P, Anjidani N, Shahpari R, Mardani M, Sabzvari A, Yazdani B, Kafi H, Fallah N, Ebrahimi A, Taheri A, Petrovsky N, Barati S. Evaluating the efficacy and safety of SpikoGen(R), an Advax-CpG55.2-adjuvanted severe acute respiratory syndrome coronavirus 2 spike protein vaccine: a phase 3 randomized placebo-controlled trial. Clin Microbiol Infect. 2023 Feb;29(2):215-220. doi: 10.1016/j.cmi.2022.09.001. Epub 2022 Sep 10.

  PMID: 36096430 BACKGROUND

• Honda-Okubo Y, Sajkov D, Wauchope B, Turner JV, Vote B, Antipov A, Andre G, Lebedin Y, Petrovsky N. Immunogenicity and safety study of a single dose of SpikoGen(R) vaccine as a heterologous or homologous intramuscular booster following a primary course of mRNA, adenoviral vector or recombinant protein COVID-19 vaccine in ambulatory adults. Vaccine. 2025 Mar 7;49:126744. doi: 10.1016/j.vaccine.2025.126744. Epub 2025 Feb 5.

  PMID: 39914274 DERIVED

MeSH Terms

Conditions

COVID-19

Interventions

SARS-CoV-2 recombinant spike protein with delta inulin and CpG-ODN adjuvant vaccine

Condition Hierarchy (Ancestors)

Pneumonia, Viral; Pneumonia; Respiratory Tract Infections; Infections; Virus Diseases; Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; RNA Virus Infections; Lung Diseases; Respiratory Tract Diseases

Study Officials

• Dimitar Sajkov, MD/PhD

  ARASMI

  PRINCIPAL INVESTIGATOR

• Nikolai Petrovsky, MD/PhD

  Vaxine Pty Ltd

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: NA
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: All subjects will receive the same single intervention with analysis groups being based on the type of primary vaccine received

Study Record Dates

• First Submitted: September 8, 2022
• First Posted: September 16, 2022
• Study Start: September 7, 2022
• Primary Completion: December 31, 2023
• Study Completion: September 16, 2025
• Last Updated: September 17, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

AU (1)