Trial NCT04551547
Publication Wang L, Nat Commun, 2022
Dates: 2020-12-12 to 2020-12-20
Funding: Mixed (National Key Research and Development Program and Beijing Science and Technology Program. The first author and five other authors are/were affiliated to Sinovac Biotech Ltd. or Sinovac Life Sciences Co., Ltd, Beijing, China.)
Conflict of interest: Yes

Methods
RCT
Location : Single center / China
Follow-up duration (months): 1
1.5 mcg CoronaVac 10 months (n=96)
3.0 mcg CoronaVac 10 months (n=96)
1.5 mcg CoronaVac 12 months (n=96)
3.0 mcg CoronaVac 12 months (n=96)
Inclusion criteria
  • Healthy children and adolescents aged 3–17 years
  • the subject and/or guardian can understand and voluntarily sign the informed consent form (double sign required for 8-17 years old)
  • proven legal identity.
Exclusion criteria
  • Travel history / residence history of communities with case reports within 14 days
  • History of contact with a SARS-CoV-2 infection (positive in nucleic acid test) within 14 days
  • Have contacted patients with fever or respiratory symptoms from communities with case reports within 14 days
  • Two or more cases of fever and / or respiratory symptoms in a small contact area of volunteers, such as home, office etc. within 14 days
  • History of SARS-CoV-2 infection
  • History of asthma, history of allergy to the vaccine or vaccine components, or serious adverse reactions to the vaccine, such as urticaria, dyspnea, and angioedema
  • Congenital malformations or developmental disorders, genetic defects, severe malnutrition, etc.
  • Autoimmune disease or immunodeficiency / immunosuppression
  • Severe chronic diseases, severe cardiovascular diseases, hypertension and diabetes that cannot be controlled by drugs, liver or kidney diseases, malignant tumors, etc.
  • Severe neurological disease (epilepsy, convulsions or convulsions) or mental illness
  • Thyroid disease or history of thyroidectomy, spleenlessness, functional spleenlessness, spleenlessness or splenectomy resulting from any condition
  • Diagnosed abnormal blood coagulation function (eg, lack of blood coagulation factors, blood coagulopathy, abnormal platelets) or obvious bruising or blood coagulation
  • Immunosuppressive therapy, cytotoxic therapy, inhaled corticosteroids (excluding allergic rhinitis corticosteroid spray therapy, acute noncomplicated dermatitis superficial corticosteroid therapy) in the past 6 months
  • Physical examination has clinically significant abnormal hematology and biochemistry laboratory test results that exceed the reference value range (only applicable to phase I clinical trials): Blood routine test: white blood cell count, hemoglobin, platelet count
  • Detection of blood biochemical indicators: alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), creatinine (CR), fasting blood glucose
  • Urine routine index: urine protein (PRO)
  • History of alcohol or drug abuse
  • Receipt of blood products within in the past 3 months
  • Receipt of other investigational drugs in the past 30 days
  • Receipt of attenuated live vaccines in the past 14 days
  • Receipt of inactivated or subunit vaccines in the past 7 days
  • Acute diseases or acute exacerbation of chronic diseases in the past 7 days
  • Axillary temperature >37.0°C
  • Already pregnant (including a positive urine pregnancy test) or are breastfeeding, planning to get pregnant within 3 months
  • According to the investigator's judgment, the subject has any other factors that are not suitable for participating in the clinical trial.
Interventions
Intervention
1 IM dose of 1.5mcg, 10 months following completion of the primary series
1 IM dose of 3mcg, 10 months following completion of the primary series
Control
1 IM dose of 1.5mcg, 12 months following completion of the primary series1 IM dose of 3mcg, 12 months following completion of the primary series
Participants
Randomized
384 participants
Characteristics of participants
Type of participants: Children and adolescents
N=384
184 males
Pregnant women: 0
Immunocompromized patients: 0
Mean age:
Age range: 3-17
Description of participants
Children and adolescents aged 3-17 years without previous history of SARS-CoV-2 infection at a single center in China.
Primary outcome
In the register
1)Safety index-incidence of adverse reactions [ Time Frame: Day 0-28 after each dose vaccination ] 2) Immunogenicity index-seroconversion rates of neutralizing antibody [ Time Frame: The 28th day after the second dose vaccination ] Neutralizing antibody assay will be performed using the micro-neutralization method. Seroconversion will be defined as a change from seronegative (<1:8) to seropositive (≥1:8), or ≥4 fold increase from baseline.
In the report
1) incidence rate of adverse reactions that occurred within 28 days after the third dose 2) immunogenicity following a third dose of CoronaVac
Documents
available

Protocol

Yes. In English

Statistical plan

Yes

Data-sharing stated: Yes, This clinical trial is ongoing, and all the individual participant data cannot be available until the immune persistence evaluation is conducted.
Data accessibility: Researchers who provide a scientifically sound proposal will be allowed to access to the de-identified individual participant data. These proposals will be reviewed and approved by the sponsor, investigators and collaborators on the basis of scientific merit. To gain access, data requestors will need to sign a data access agreement. Proposals should be directed to gaoq@sinovac.com. Corresponding author is Qiang Gao: gaoq@sinovac.com
Risk of bias
Overall
The overall risk of bias reported in the table corresponds to the highest risk of bias for the outcomes assessed for the systematic review
Some concerns
General comment In addition to the published article, the study registry was used in data extraction and risk of bias assessment. The target sample size (n=552) specified in the registry was not achieved (n=480). The article presented interim analyses for a study with ongoing follow-up.