A Real-world Study to Evaluate the Safety and Immunogenicity of a Third-dose Booster After Two Doses of an Inactivated COVID-19 Vaccine

Study Overview
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Brief Summary
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This project is a prospective observational real-world study, recruiting and screening subjects who have completed 2 doses of the COVID-19 vaccine for more than 6 months and receive the third dose of the vaccine voluntarily into the clinical cohort of this study. Subjects received a third dose of the COVID-19 vaccine will be enrolled in the study and followed up for 1 year at baseline (day 0) before vaccine injection, 28 days after injection, 90 days, 270 days after injection. On the 365th day, blood samples were collected for the detection of anti-SARS-CoV-2 antibodies and other related indicators to evaluate the immune protection effect.

Official Title
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A Real-world Study to Evaluate the Safety and Immunogenicity of a Third-dose Booster After Two Doses of an Inactivated COVID-19 Vaccine

Conditions
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COVID-19, Vaccine Reaction

Intervention / Treatment
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* Biological: an inactivated SARS-CoV-2 vaccine named BBIBP-CorV


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age >18 years old, gender is not limited; Subjects who completed the second dose of COVID-19 inactivated vaccine for more than 6 months and received the third dose of the same vaccine Exclusion Criteria: allergic to the active ingredients of the SARS-CoV-2 vaccine, any of the inactive ingredients, the substances used in the production process, or those who have had allergies during previous vaccination of similar vaccines; those who have had severe allergic reactions to vaccines in the past (such as acute allergic reactions, angioedema, respiratory Difficulties, urticaria, angioedema or abdominal pain); Receiving other research drugs within 3 months ;participating in other research vaccines Or subjects in clinical trials of research drugs; other conditions that the investigator judges are not suitable for this clinical trial;

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Biological: an inactivated SARS-CoV-2 vaccine named BBIBP-CorV|Completed 2 doses of an inactivated SARS-CoV-2 vaccine more than 6 months ago and received a third dose of the vaccine|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Geometric mean titers (GMTs) | Geometric mean titers (GMTs) of serum COVID-19 neutralizing antibodies | Day 28±3 after the third dose of vaccine injection | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Geometric mean titers (GMTs) | Geometric mean titers (GMTs) of serum COVID-19 neutralizing antibodies | Day 90±7, Day 180±7, Day 270±7, Day 365±7 after the third dose of vaccine injection | 
| IgG | Serum SAS-CoV-2 IgG | Day 28±3, Day 90±7, Day 180±7, Day 270±7, Day 365±7 after the third dose of vaccine injection | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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inactive vaccine