Heterologous Booster Study of COVID-19 Protein Subunit Recombinant Vaccine in Children 12-17 Years of Age

Immunogenicity and Safety of IndoVac® as a Heterologous Booster Dose Against COVID-19 in Children 12-17 Years of Age

The goal of this clinical trial is to evaluate immune response and safety of SARS-CoV-2 subunit protein recombinant vaccine (IndoVac) as a heterologous booster dose in healthy children 12-17 years of age.

Participants who had received complete primary doses of inactivated (Sinovac®) COVID-19 Vaccine will be given IndoVac as a booster dose.

Study Overview

• Status: Completed
• Conditions: COVID-19
• Intervention / Treatment: Biological: SARS-CoV-2 subunit protein recombinant vaccine

Detailed Description

This trial is open label prospective intervention study. In this study 150 subjects who had received complete primary doses of inactivated (Sinovac®) COVID-19 Vaccine and willing to participate in the booster study by signing the consent form, will be involved in this trial.

Subject will receive one booster dose of SARS-CoV-2 subunit protein recombinant vaccine (IndoVac).

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

Contacts and Locations

Study Locations

• Indonesia
  • Jawa Barat
    • Bandung, Jawa Barat, Indonesia, 40161
      • Faculty of Medicine Universitas Padjadjaran

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 12 years to 17 years (Child)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. Clinically healthy children 12-17 years of age.
2. Subjects who have previously received complete primary series of inactivated (Sinovac®) COVID-19 vaccine with the last dose administered a minimum of 6 months prior to inclusion but not longer than 12 months prior to inclusion.
3. Parent/legal guardian and subject has been informed properly regarding the study, and signed the informed consent form (parent/legal guardian) and assent form (subject).
4. Parent and/or legal guardian will commit to comply with the instructions of the investigator and the schedule of the trial.

Exclusion Criteria:

1. Subject concomitantly enrolled or scheduled to be enrolled in another trial.
2. Subject who has received booster dose of COVID-19 vaccine.
3. Subject who has history of COVID-19 in the last 3 months (based on anamnesis or other examinations).
4. Evolving mild, moderate or severe illness, especially infectious disease or fever (body temperature ≥37.5℃, measured with infrared thermometer/thermal gun).
5. History of uncontrolled asthma, history of allergy to vaccines or vaccine ingredients, and severe adverse reactions to vaccines, such as urticaria, dyspnea, and angioneurotic edema.
6. History of uncontrolled coagulopathy or blood disorders contraindicating intramuscular injection.
7. Patients with serious chronic diseases (serious cardiovascular diseases, uncontrolled hypertension and diabetes, liver and kidney diseases, malignant tumors, etc) which according to the investigator might interfere with the assessment of the trial objectives.
8. Subjects who have any history of confirmed or suspected immunosuppressive or immunodeficient state, or received in the previous 4 weeks a treatment likely to alter the immune response (intravenous immunoglobulins, blood-derived products or long-term corticosteroid therapy (> 2 weeks)).
9. Subjects who have history of uncontrolled epilepsy or other progressive neurological disorders, such as Guillain-Barre Syndrome.
10. Subjects receive any vaccination (other than COVID-19 vaccine) within 1 month before and after IP immunization.
11. Female who are pregnant or planning to become pregnant during the study period (judged by self-report of subjects and urine pregnancy test results).
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: Primary dose of inactivated (Sinovac®) vaccine; Subject who had received a complete primary dose of inactivated (Sinovac®) vaccine	Biological: SARS-CoV-2 subunit protein recombinant 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
Immunogenicity of the candidate vaccine	Geometric Mean Titer (GMT) and GMFR of neutralizing antibody to the SARS-CoV-2	14 days after booster vaccination

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Seropositive rate of the candidate vaccine	Seropositive rate of neutralizing antibody	baseline, 14 days, 3 months, 6 months, and 12 months after booster vaccination
Seroconversion rate of the candidate vaccine	Seroconversion rate of neutralizing antibody	baseline and 14 days after booster vaccination
Seropositive rate and GMT of candidate vaccine	Seropositive rate and GMT of IgG antibody (RBD)	baseline, 14 days, 3 months, 6 months, and 12 months after booster vaccination
Seroconversion rate of candidate vaccine	Seroconversion rate of IgG antibody (RBD)	baseline and 14 days after booster vaccination
Safety of the candidate vaccine	Percentage of subjects with solicited and unsolicited Adverse Events (AE)	30 minutes, 7 days, 28 days, and until 12 months after booster vaccination
Serious Adverse Event (SAE) of the vaccine	Percentage of subjects with at least 1 SAE	until 12 months after booster vaccination

Collaborators and Investigators

• Sponsor: PT Bio Farma
• Collaborators: Universitas Padjadjaran
• Investigators: Principal Investigator: Eddy Fadlyana, MD, Universitas Padjadjaran

Study record dates

Study Major Dates

• Study Start (Actual): February 28, 2023
• Primary Completion (Actual): February 22, 2024
• Study Completion (Actual): March 18, 2024

Study Registration Dates

• First Submitted: February 13, 2023
• First Submitted That Met QC Criteria: February 13, 2023
• First Posted (Actual): February 14, 2023

Study Record Updates

• Last Update Posted (Actual): June 3, 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; Children; Heterologous; COVID-19 vaccine; healthy population
• 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-Children-0222

Drug and device information, study documents

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