Study on Antibody Persistence and Immune Memory of Inactivated COVID-19 Vaccine

A Prospective Cohort Study on Antibody Persistence and Immune Memory After Two Doses of Inactivated COVID-19 Vaccine in 150 People

The study describe 1 year durability of humoral and cellular immune responses in 150 individuals who received COVID-19 inactivated vaccine. all participants were recruited aged between 18 and 59 years old. Every participant was familiarized with the aim of the study and asked to sign an informed consent agreement, and be required blood sampling at the day 0 of first dose vaccine and 1 month, 3 months, 6 months and 12 months after fully vaccination separately. From every sample, 10 ml, 10 ml, and 5 ml were dispensed in three vacuum blood collection tubes. Peripheral blood lymphocytes cell (PBMC) were isolated with the two 10 ml samples contained heparin to detect immune memory cells and cytokines. RBD-IgG and neutralizing antibody be detected by 5ml sample from separating gel vacuum tubes. every individual conducted a detailed analysis comparing neutralizing antibody, TEM, TCM , and report on the cellular and humoral immunity 1 year after accept COVID-19 vaccine.

Study Overview

• Status: Completed
• Conditions: COVID-19

• Study Type: Observational
• Enrollment (Actual): 150

Contacts and Locations

Study Locations

• China
  • Beijing, China
    • Beijing Center for Disease Control and Prevention

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 59 years (ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

The healthy people aged between 18 and 59, and have not been infected with COVID-19, have not been vaccinated with COVID-19 vaccine, and agree to collect blood samples.

Description

Inclusion Criteria:

• Working at the CDC
• Between the ages of 18 and 59
• Healthy
• Not vaccinated with COVID-19 vaccine
• Agreed to take a blood sample

Exclusion Criteria:

• who cannot take the COVID-19 vaccine due to some personal reasons
• history of SARS-CoV, SARS-CoV-2, or Middle East respiratory syndrome infection
• high-risk epidemiology history within 14 days before enrolment (eg, travel or residence history in communities with case reports, or contact history with someone infected with SARS-CoV-2)
• axillary temperature of more than 37·0℃
• history of allergy to any vaccine component.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Durability of humoral and cellular immune responses	The humoral immunogenicity outcomes include the RBD-specific IgG titers and neutralising antibodies amounts at 1, 3, 6, and 12 months after the second shot. The positive cutoff for RBD-specific IgG antibodies was defined as the sample cutoff (S/CO) value ≥1.0. Seroconversion of neutralising antibodies was defined as a change from seronegative at baseline to seropositive or a four-fold titre increase. The positive cutoff of the titre for neutralising antibodies was 1/4. The cellular immune response outcomes measured by ICS assays across the blood collection time points.the percentage of RBD-specific CD4+ CD8+ memory T cells after vaccination.	12 months after fully vaccination

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The dynamic variation of the level of antibody	RBD-IgG and neutralizing antibody level after vaccination at 1,3 and 6 ,12months vaccination.	1，3，6 , 12 month
Cytokine secretion by peripheral blood mononuclear cells	To study the cytokine production of PBMC after stimulation with RBD after vaccination at 1,3,6 and 12 months vaccination,for examples IL-2,IL-5,IFN and GrB.	1,3,6,12 month
TCM and TEM amount varies at different time points	The dynamic variation of specificity TCM and TEM after vaccination at 1,3,6 and 12 months vaccination.	1,3,6,12 month

Collaborators and Investigators

• Sponsor: Centers for Disease Control and Prevention, China

Study record dates

Study Major Dates

• Study Start (ACTUAL): July 20, 2020
• Primary Completion (ACTUAL): August 30, 2021
• Study Completion (ACTUAL): September 27, 2021

Study Registration Dates

• First Submitted: September 29, 2021
• First Submitted That Met QC Criteria: October 8, 2021
• First Posted (ACTUAL): October 11, 2021

Study Record Updates

• Last Update Posted (ACTUAL): October 11, 2021
• Last Update Submitted That Met QC Criteria: October 8, 2021
• Last Verified: October 1, 2021

More Information

Terms related to this study

• Keywords: cohort study; Antibody persistence; cellular immunity; Inactivated vaccine
• Additional Relevant MeSH Terms: Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; RNA Virus Infections; Virus Diseases; Infections; Respiratory Tract Infections; Respiratory Tract Diseases; Pneumonia, Viral; Pneumonia; Lung Diseases; COVID-19
• Other Study ID Numbers: BJCDCWJ202101

Drug and device information, study documents

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