To evaluate the post-marketing immunogenicity, safety and antibody persistence of the third dose (booster) of Covid-19 vaccine in patients aged 60 years or older with hypertension and/or diabetes.
After giving informed consent, patients with hypertension, patients with diabetes, patients with both diseases, and healthy controls, all aged 60 years or older, are given a third doses of the inactivated SARS-CoV-2 vaccine (Vero cells). These subjects are all from the "COVAX (HT/DM)-Wuhan" clinical trial (NCT05065892). 50% of them receive the booster vaccine 3 months after the second dose (0-1-4 schedule); 50% of them receive the booster vaccine 5 months after the second dose (0-1-6 schedule). Venous blood samples are collected before the booster dose and on day 28 after the booster dose to evaluate the immunogenicity of the vaccine. Venous blood samples are also collected on day 84/168/252/336 after the booster dose to evaluate the antibody persistence of the vaccine. Adverse events are actively recorded on a diary card once daily from day 0 to day 7 and once from day 8 to day 21 after the booster dose. Serious adverse events (SAE) are collected within 6 months after the booster dose.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
PREVENTION
Masking
SINGLE
Enrollment
1,440
Subjects receive the booster vaccine 3 months after the second dose.
Subjects receive the booster vaccine 5 months after the second dose.
Nan'an Center for Disease Control and Prevention
Quanzhou, Fujian, China
Songtao Miao Autonomous County Center for Disease Control and Prevention
Tongren, Guizhou, China
You County Center for Disease Control and Prevention
Zhuzhou, Hunan, China
Seroconversion rate
the rate of positive seroconversion against coronavirus
Time frame: Up to 28 days after the booster dose
Neutralizing antibody level
neutralizing antibody level against coronavirus
Time frame: Up to 28 days after the booster dose
Neutralizing antibody level
neutralizing antibody level against coronavirus
Time frame: Up to 84 days after the booster dose
Neutralizing antibody level
neutralizing antibody level against coronavirus
Time frame: Up to 168 days after the booster dose
Neutralizing antibody level
neutralizing antibody level against coronavirus
Time frame: Up to 252 days after the booster dose
Neutralizing antibody level
neutralizing antibody level against coronavirus
Time frame: Up to 336 days after the booster dose
Adverse events following vaccination
analyse the incidence of adverse events following immunization, both solicited and unsolicited
Time frame: Up to 6 months after the booster dose
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