COVID-19, SARS-CoV-2 Infection
Conditions
Keywords
mRNA vaccine, COVID-19 vaccines, SYS6006, Omicron variant, Hybrid immunity, Post-marketing surveillance, Immunogenicity, Safety
Brief summary
This is a multicentre post-marketing cohort study to evaluate the immunogenicity and safety of a single dose of mRNA SARS-CoV-2 vaccine SYS6006 in Chinese adults predominantly with hybrid immunity. A total of 2,052 adults aged 18 years and older who received one dose of SYS6006 were monitored for serious adverse events (SAEs) for 6 months. The first 60 participants comprised an immunogenicity subgroup, with blood samples collected before vaccination and at day 14, month 3, and month 6 post-vaccination to assess humoral and cellular immune responses.
Detailed description
This study evaluated the immunogenicity and safety of a single dose of the mRNA SARS-CoV-2 vaccine SYS6006 (CSPC Megalith Biopharmaceutical Co., Ltd, Shijiazhuang, China) in Chinese adults aged 18 years and older predominantly with hybrid immunity against COVID-19. Between May and August 2023, 2,052 adults in five cities of Jiangsu Province, China (Taizhou, Changzhou, Lianyungang, Suqian, and Wuxi) received one intramuscular dose of SYS6006 (30 μg mRNA/0.3 mL) and were followed for 6 months to monitor serious adverse events (SAEs). The first 60 participants comprised the immunogenicity subgroup; serum and peripheral blood mononuclear cells (PBMCs) were collected before vaccination and at day 14, month 3, and month 6 post-vaccination. Immunogenicity assessments included pseudovirus neutralizing antibody geometric mean titres (GMTs) against wild-type (WT), BA.4/5, and XBB.1.16; receptor-binding domain (RBD)-specific IgG and IgA; ACE2-RBD binding inhibition; Fc-mediated effector functions (ADCP, ADCC, ADNP); and IFN-γ/IL-2 ELISpot responses.
Interventions
BIOLOGICALSYS6006
Lipid nanoparticle (LNP)-encapsulated mRNA SARS-CoV-2 vaccine, 30 μg mRNA/0.3 mL, single intramuscular dose.
Sponsors
Jiangsu Province Centers for Disease Control and Prevention
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
1. Adults aged 18 years and over, including the elderly over 60 years and those with general underlying diseases. 2. At least 4 months since the last SARS-CoV-2 infection (or never infected), and at least 6 months since the last COVID-19 vaccination. 3. Able and willing to comply with the study procedures and to provide written informed consent.
Exclusion criteria
1. Suspected COVID-19 symptoms on the day of enrollment (e.g., dry/sore throat, cough). 2. Positive SARS-CoV-2 antigen rapid test at enrollment. 3. Prior receipt of the first COVID-19 booster dose . 4. History of severe adverse reactions or anaphylaxis related to vaccination, or known severe allergy to any vaccine component. 5. Pregnant or lactating women. 6. Any other condition that, in the investigator's judgment, makes the individual unsuitable for the study. \-
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Geometric mean titer (GMT) of neutralizing antibodies in the immunogenicity subgroup | 14 days after booster immunization | Measured in the immunogenicity subgroup at 14 days after booster immunization. |
| Incidence of serious adverse events (SAEs) | Within 6 months after the booster administration | Serious adverse events monitored for 6 months after the booster administration. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Geometric mean concentration (GMC) of serum RBD-specific IgG | Day 14 after booster immunization | GMC of serum RBD-specific IgG antibodies against WT and Omicron variants, measured by ELISA after booster immunization |
| Geometric mean concentration (GMC) of serum RBD-specific IgA | Day 14 after booster immunization | GMC of serum RBD-specific IgA antibodies against WT and Omicron variants, measured by ELISA after booster immunization |
| ACE2-RBD binding inhibition rate | Day 14 after booster immunization | Rate of inhibition of ACE2-RBD binding in serum, measured by surrogate virus neutralization / competitive binding assay after booster immunization. |
| Antigen-specific T-cell response measured by ELISpot | Day 14 after booster immunization | Frequency of antigen-specific T cells (spot-forming cells) in peripheral blood measured by ELISpot assay after booster immunization. |
Countries
China
Outcome results
None listed