heterologous boost immunization with an aerosolised ad5-ncov after two-dose priming with an inactivated sars-cov-2 vaccine

Conditions: COVID-19

Summary: this is a multicenter, open-label, partially radomized, parallel-controlled clinical trial to evaluate the safety and immunogenicity of heterologous prime-boost immunization with an aerosolised adenovirus type-5 vector-based covid-19 vaccine (ad5-ncov-ih) after two-dose priming with an inactivated sars-cov-2 vaccine (icv) in adults aged 18 years and above. 10420 healthy subjects aged over or equal to 18 years whom have received two doses of icv before 6 months or more, will be recruited from six provinces in china in this study.of them, 10000 eligible participants in an open cohort will receive a booster dose of ad5-ncov-ih to evaluate the safety profile. another 420 participants were involved in immunogenicity cohort and randomized in a ratio of 1:1 to receive a boost of ad5-ncov-ih or icv. the icv homologous to the priming series will be supplied as the booster. the occurrence of adverse reactions within 28 days and serious adverse events within 6 months after vaccination will be observed in all participants. in addition, blood and saliva samples will be collected from all participants in immunogenicity cohort on the day 0 before and 14, 28 and month 3 and 6 after the booster vaccination. each subject will remain in this study for approximately 6 months.


Eligibility criteria:
inclusion criteria: * health subjects aged ≥18 years. * have received two-dose inactivated sars-cov-2 vaccine before 6 months or more. * the subject can provide with informed consent and sign informed consent form (icf). * the subjects are able to and willing to comply with the requirements of the clinical trial program and could complete the 6-month follow-up of the study. exclusion criteria: * have the medical history or family history of convulsion, epilepsy, encephalopathy and psychosis. * be allergic to any component of the research vaccines, or used to have a history of hypersensitivity or serious reactions to vaccination. * women with positive urine pregnancy test. * have acute febrile diseases and infectious diseases. * axillary temperature\>37.0℃. * have serious cardiovascular disease, such as arrhythmia, conduction block, myocardial infarction, severe hypertension that cannot be controlled by medication (systolic blood pressure ≥180mmhg and/or diastolic blood pressure ≥110mmhg when measured in the field). * have severe chronic diseases or condition in progress cannot be smoothly controlled, such as asthma, diabetes, thyroid disease. * congenital or acquired angioedema / neuroedema. * have the history of urticaria 1 year before receiving the investigational vaccine. * have asplenia or functional asplenia. * patients with chronic obstructive pulmonary disease, pulmonary fibrosis and other pulmonary abnormalities. * have history of sars-cov-2 infection or covid-19. * have symptoms of upper respiratory tract infection. * have traveled to medium or high risk areas or traveled abroad in the past 21 days, and epidemiologically contacted with sars-cov-2. * any medical, psychological, social, or other conditions that, in the investigator's judgment, are inconsistent with the protocol or affect the subject's informed consent.

Keywords: sars-cov-2 aerosolised covid-19 vaccine recombinant ad5 vector inactivated vaccine safety immunogenicity