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

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT05072496

Enrollment

150

Registered

2021-10-11

Start date

2020-07-20

Completion date

2021-09-27

Last updated

2021-10-11

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

COVID-19

Keywords

Inactivated vaccine, cohort study, Antibody persistence, cellular immunity

Brief summary

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.

Interventions

None listed

Study design

Observational model

COHORT

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

18 Years to 59 Years

Healthy volunteers

Yes

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.

Design outcomes

Primary

Measure	Time frame	Description
Durability of humoral and cellular immune responses	12 months after fully vaccination	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.

Secondary

Measure	Time frame	Description
The dynamic variation of the level of antibody	1，3，6 , 12 month	RBD-IgG and neutralizing antibody level after vaccination at 1,3 and 6 ,12months vaccination.
Cytokine secretion by peripheral blood mononuclear cells	1,3,6,12 month	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.
TCM and TEM amount varies at different time points	1,3,6,12 month	The dynamic variation of specificity TCM and TEM after vaccination at 1,3,6 and 12 months vaccination.

Countries

China

Outcome results