Homologous Booster Study of COVID-19 Protein Subunit Recombinant Vaccine

Immunogenicity & Safety of IndoVac® as a Homologous Booster Dose Against COVID-19 in Adults Aged 18 Years and Above in Indonesia

Open-label, prospective intervention study of IndoVac® as a single, homologous booster dose

Study Overview

• Status: Completed
• Conditions: COVID-19
• Intervention / Treatment: Biological: SARS-CoV-2 Subunit Recombinant Protein Vaccine

Detailed Description

This trial is open-label, prospective intervention study. A total of 150 subjects who had previously received complete primary doses of IndoVac® in phase III and are willing to participate in the study by signing the consent form, will be involved in this trial. The regimen of the vaccine 0.5 ml injected as a single booster dose.

Evaluation will be conducted for safety and immunogenicity for all subjects. Safety evaluation include AEs until 28 days post booster dose, with AESIs and SAEs throughout the trial. Immunogenicity evaluation will compare pre-booster antibody titer (baseline) to post- booster antibody titer at 14 days, 28 days, 3 months, 6 months, and 12 months timepoint. Interim evaluation will be performed at 14 days post booster dose for Emergency Use Authorization (EUA) consideration. All subjects will be followed up until 12 months post booster dose.

• Study Type: Interventional
• Enrollment (Actual): 150
• Phase: Phase 2

Contacts and Locations

Study Locations

• Indonesia
  • Central Java
    • Semarang, Central Java, Indonesia
      • Faculty of Medicine Diponegoro University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. Clinically healthy subjects aged 18 years and above.
2. Subjects had previously received complete primary doses of IndoVac® with the last dose administered minimum 12 months but no longer than 18 months prior to inclusion.
3. Subjects have been informed properly regarding the study and signed the informed consent form.
4. Subjects will commit to comply with the instructions of the investigator and the schedule of the trial.

Exclusion Criteria:

1. Subjects concomitantly enrolled or scheduled to be enrolled in another trial.
2. Subjects had received booster dose of COVID-19 vaccine.
3. History of COVID-19 within 3 months prior to enrollment (based on anamnesis or other examinations).
4. Evolving mild, moderate, or severe illness, especially infectious disease, or fever (body temperature ≥37.5°C, measured with infrared thermometer/thermal gun).
5. Women who are pregnant or planning to become pregnant during the study period (judged by self- report of subjects and urine pregnancy test results).
6. History of uncontrolled asthma, allergy to vaccines or vaccine ingredients, and severe adverse reactions to vaccines, such as urticaria, dyspnea, and angioneurotic edema.
7. History of uncontrolled coagulopathy or blood disorders contraindicating intramuscular injection.
8. Patients with serious chronic diseases (serious cardiovascular diseases, uncontrolled hypertension or diabetes, liver or kidney diseases, malignant tumors, etc.) which according to the investigator might interfere with the assessment of the trial objectives.
9. History of confirmed or suspected immunosuppressive or immunodeficient state or in the previous 4 weeks had received a treatment likely to alter the immune response (intravenous immunoglobulins, blood-derived products, or long- term corticosteroid therapy (> 2 weeks)).
10. History of uncontrolled epilepsy or other progressive neurological disorders, such as Guillain- Barre Syndrome.
11. Subjects had received any vaccination (other than COVID-19 vaccine) within 1 month before IP immunization.
12. Subjects plan to move from the study area before the end of study period.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Participants who previously completed primary doses of vaccine	Biological: SARS-CoV-2 Subunit Recombinant Protein Vaccine; SARS-CoV-2 RBD subunit recombinant protein, manufactured by PT Bio Farma

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Neutralizing antibody before and at 14 days after booster dose	Geometric Mean Titer (GMT) and Geometric Mean Fold Ratio (GMFR) of SARS-CoV-2 neutralizing antibody against Omicron variant	Baseline, 14 days after booster dose

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Safety after booster dose	Number and percentage of subjects with solicited and unsolicited Adverse Events (AEs), Serious Adverse Events (SAEs), Adverse Events of Special Interest (AESIs)	Baseline to 12 months after booster dose
Neutralizing antibody at 28 days after booster dose	Geometric Mean Titer (GMT) and Geometric Mean Fold Ratio (GMFR) of SARS-CoV-2 neutralizing antibody against Omicron variant	Baseline, 14 days, 28 days after booster dose
RBD-binding IgG antibody before, at 14 days and 28 days after booster dose	Geometric Mean Titer (GMT) and Geometric Mean Fold Ratio (GMFR) of SARS-CoV-2 RBD-binding IgG antibody	Baseline, 14 days, 28 days after booster dose
Antibody persistence at 3, 6, and 12 months after booster dose	Geometric Mean Titer (GMT) and Geometric Mean Fold Ratio (GMFR) of SARS-CoV-2 RBD-binding IgG antibody	Baseline, 3 months, 6 months, 12 months after booster dose

Collaborators and Investigators

• Sponsor: PT Bio Farma
• Investigators: Principal Investigator: Yetty Movieta Nency, MD, Faculty of Medicine Universitas Diponegoro

Study record dates

Study Major Dates

• Study Start (Actual): July 25, 2023
• Primary Completion (Actual): August 31, 2024
• Study Completion (Actual): September 5, 2024

Study Registration Dates

• First Submitted: July 5, 2023
• First Submitted That Met QC Criteria: July 5, 2023
• First Posted (Actual): July 6, 2023

Study Record Updates

• Last Update Posted (Estimated): June 5, 2025
• Last Update Submitted That Met QC Criteria: June 2, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Keywords: Booster; COVID-19 vaccine
• Additional Relevant MeSH Terms: Respiratory Tract Infections; Infections; RNA Virus Infections; Virus Diseases; Respiratory Tract Diseases; Lung Diseases; Pneumonia, Viral; Pneumonia; Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; COVID-19
• Other Study ID Numbers: CoV2-Booster 0323

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No