MedPath

Immunogenicity and Safety of a Third Dose of COVID-19 Vaccine(Vero Cell), Inactivated in the Elderly

Phase 4
Completed
Conditions
COVID-19
Interventions
Biological: COVID-19 Vaccine (Vero cell), Inactivated
Registration Number
NCT05398926
Lead Sponsor
Sinovac Life Sciences Co., Ltd.
Brief Summary

This is an open phase Ⅲ clinical trial of COVID-19 vaccine (Vero cell), inactivated manufactured by Sinovac Research \& Development Co., Ltd.The purpose of this study is to evaluate Immunogenicity and safety of a third dose at different times after two-dose of COVID-19 vaccine (Vero cell), Inactivated in the Elderly Aged 60 years and above.

Detailed Description

This study is an open phase Ⅲ clinical trial. The main purpose of this study is to evaluate Immunogenicity and safety of a third dose at different times after two-dose of COVID-19 vaccine (Vero cell), Inactivated manufactured by Sinovac Research \& Development Co., Ltd. in the elderly aged 60 years and above.A total of 400 subjects aged 60 years and above who had received two doses of COVID-19 vaccine(Vero Cell), inactivated manufactured by Sinovac Research \& Development Co., Ltd. between 3 - 6 months ago (100 subjects for 3 months, 4 months, 5 months and 6 months,respectively) will be enrolled and receive a third dose of two-dose of COVID-19 vaccine (Vero cell), inactivated were enrolled.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
400
Inclusion Criteria
  • Subjects aged 60 years and above;
  • Provide legal identification;
  • Have completed two-dose of COVID-19 vaccine (Vero cell), inactivated manufactured by Sinovac Research& Development Co., Ltd. for 3~6 months(The interval between two doses was 21~35 days);
  • Be able to understand and voluntarily sign the informed consent form and be willing to complete the study according to the research plan.
Exclusion Criteria
  • History of SARS-CoV-2 infection(laboratory confirmed);
  • Those who have received COVID-19 vaccine from other manufacturers other than Sinovac Research& Development Co., Ltd., or who have received booster immunization with COVID-19 vaccine after two doses of COVID-19 vaccine (Vero cell),inactivated manufactured by Sinovac Research& Development Co., Ltd.;
  • History of serious adverse reactions to the vaccine or vaccine components, such as urticaria dyspnea and angioneuroedema;
  • 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;
  • Immunosuppressive therapy, cytotoxic therapy, inhaled corticosteroids(excluding allergic rhinitis corticosteroid spray therapy, acute noncomplicated dermatitis superficial corticosteroid therapy) in the past 6 months or plan to receive these treatments during the study period;
  • Receipt of blood products within in the past 3 months or plan to receive these treatments during the study period;
  • Receipt of other investigational drugs in the past 30 days;
  • Receipt of attenuated live vaccines in the past 14 days,or receipt of inactivated or subunit vaccines in the past 7 days;
  • Onset of various acute or chronic diseases within 7 days prior to the study;
  • Axillary temperature >37.0°C;
  • According to the investigator's judgment, the subject has any other factors that are not suitable for participating in the clinical trial.

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Experimental group 3 (5-month interval)COVID-19 Vaccine (Vero cell), Inactivated100 subjects who have received two doses of COVID-19 vaccine (Vero cell), Inactivated will receive a 3rd dose of the vaccine (5-month interval).
Experimental group 1 (3-month interval)COVID-19 Vaccine (Vero cell), Inactivated100 subjects who have received two doses of COVID-19 vaccine (Vero cell), Inactivated will receive a 3rd dose of the vaccine (3-month interval).
Experimental group 2 (4-month interval)COVID-19 Vaccine (Vero cell), Inactivated100 subjects who have received two doses of COVID-19 vaccine (Vero cell), Inactivated will receive a 3rd dose of the vaccine (4-month interval).
Experimental group 4 (6-month interval)COVID-19 Vaccine (Vero cell), Inactivated100 subjects who have received two doses of COVID-19 vaccine (Vero cell), Inactivated will receive a 3rd dose of the vaccine (6-month interval).
Primary Outcome Measures
NameTimeMethod
Immunogenicity index-GMT of neutralizing antibodiesAt 14 days after vaccination

GMT of neutralizing antibodies at 14 days after vaccination

Immunogenicity index- GMT of neutralizing antibodiesAt 28 days after vaccination

GMT of neutralizing antibodies at 28 days after vaccination

Safety index-Incidence of adverse reactions0~28 days after vaccination

Incidence of adverse reactions 0\~28 days after vaccination

Secondary Outcome Measures
NameTimeMethod
Immunogenicity index-GMT of neutralizing antibodiesDay 0 before vaccination and 180 days after vaccination

GMT of neutralizing antibodies before vaccination and at different points after vaccination.

Immunogenicity index-4-fold increase rate of neutralizing antibodiesAt 14 days and 28 days after vaccination.

4-fold increase rate of neutralizing antibodies at different points after vaccination.

Safety index-Incidence of adverse reactions0~7 days after vaccination

Incidence of adverse reactions 0\~7 days after vaccination.

Immunogenicity index-seropositive rate of neutralizing antibodiesDay 0 before vaccination and 14 days, 28 days and 180 days after vaccination

Seropositive rate of neutralizing antibodies of neutralizing antibodies before vaccination and at different points after vaccination

Safety index-Incidence of serious adverse events6 months after vaccination

Incidence of serious adverse events 6 months after vaccination.

Trial Locations

Locations (1)

Yongde Center for Diseases Control and Prevention

🇨🇳

Lincang, Yunnan, China

© Copyright 2025. All Rights Reserved by MedPath