a blood collection study to assess the immunogenicity of nationally authorized homologous covid-19 booster vaccines among adult vaccinees.

Conditions: COVID-19

Summary: the purpose of this study is to assess the immunogenicity of nationally available pre-defined homologous booster vaccination of a sars-cov-2 who eua qualified vaccination in adults aged 18 years and older


Eligibility criteria:
inclusion criteria: * participant must be 18 years of age and older, at the time of signing the informed consent. * participants who are healthy or medically stable as determined by medical evaluation including medical history, physical examination, and medical judgement of the investigator. * participants who are able to attend all scheduled visits and comply with all study procedures. * participants who received primary vaccination of 1 of 6 different who eua qualified covid-19 vaccine (mrna-1273, chadox1 ncov-19, ad26.cov2.s, bnt162b2, bbibp-corv, coronavac) at least 12 weeks of gap prior to first homologous booster vaccination and with no history of other covid-19 vaccination, including booster doses. * participants who complete a qualitative test for antibody to sars-cov-2 nucleocapsid proteins at screening for assessment of previous sars-cov-2 infection. * female participants with a negative urine or serum pregnancy test at screening. * capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in this protocol. exclusion criteria: * concurrent or past sars-cov-2 infection within 12 weeks prior to the booster study vaccination confirmed by virological or serological testing . * history of congenital, hereditary, acquired immunodeficiency, or autoimmune disease. * history of bleeding disorder or thrombocytopenia which is contraindicating to take blood sample. * history of malignancy within 1 year prior to the screening (with the exception of malignancy with minimal risk of recurrence at the discretion of the investigator). * significant unstable chronic or acute illness that, in the opinion of the investigator, might pose a health risk to the participant if enrolled, or could interfere with the protocol-specified activities, or interpretation of study results. * any other conditions which, in the opinion of the investigator, might interfere with the evaluation of the study objectives (e.g., alcohol or drug abuse, neurologic or psychiatric conditions). * receipt of any medications or vaccinations intended to prevent covid-19 except for the pre-defined covid-19 vaccines expected to be given prior to screening (mrna-1273, chadox1 ncov-19, ad26.cov2.s, bnt162b2, bbibp-corv, coronavac). * receipt of any vaccine within 4 weeks prior to the booster vaccination or planned receipt of any vaccine from enrollment through 4 weeks after the booster vaccination, except for influenza vaccination, which may be received at least 2 weeks prior to the booster vaccination. * receipt of immunoglobulins and/or any blood or blood products within 12 weeks prior to the booster vaccination. * chronic use (more than 2 consecutive weeks) of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy; or long-term systemic corticosteroid therapy (≥10mg prednisone/day or equivalent for more than 2 consecutive weeks) within 12 weeks prior to the booster vaccination. the use of topical and nasal glucocorticoids will be permitted. * participation in another clinical study and or concurrent, planned participation in another clinical study with study intervention during the study period. * investigators, or study staff who are directly involved in the conduct of this study or supervised by the investigator, and their respective family members. * donation of ≥450ml of blood product within 4 weeks prior to screening, or planned donation of blood product during the study period