The 2019 novel-coronavirus (2019-nCov) is the cause of a cluster of unexplained pneumonia that started in Hubei province in China. It has manifest into a global health crisis with escalating confirmed cases and spread across many countries.

In view of the fact that there is currently no effective antiviral therapy, the prevention or treatment of diseases caused by COVID-19 can be tough for current treatment.

This study is a phase I clinical trial of booster vaccination of adenovirus type-5 vectored COVID-19 vaccine 6 months after prime vaccination. The investigators intent to evaluate the safety and immunogenicity of booster vaccination of adenovirus type-5 vectored COVID-19 vaccine in healthy adults aged aged 18-60 years.

The 2019 novel-coronavirus (2019-nCov) is the cause of a cluster of unexplained pneumonia that started in Hubei province in China. It has manifest into a global health crisis with escalating confirmed cases and spread across many countries.

In view of the fact that there is currently no effective antiviral therapy, the prevention or treatment of diseases caused by COVID-19 can be tough for current treatment.

This is a single-center, open-label phase I clinical trial of booster vaccination in healthy 18 to 60 years of age, inclusive, who has been prime vaccinated with adenovirus type-5 vectored COVID-19 vaccine. This clinical trial is designed to assess the safety and immunogenicity of booted vaccination of adenovirus type-5 vectored COVID-19 vaccine manufactured by Beijing Institute of Biotechnology and CanSino Biologics Inc.

Inclusion Criteria:

• Participants who has received prime vaccination of adenovirus type-5 vectored COVID-19 vaccine
• Able to understand the content of informed consent and willing to sign the informed consent
• Negative in HIV diagnostic test.
• Axillary temperature ≤37.0°C.
• General good health as established by medical history and physical examination.
• Able to complete 12 months visit

Exclusion Criteria:

• Family history of seizure, epilepsy, brain or mental disease
• Subject allergic to any component of the investigational vaccine, or a more severe allergic reaction and history of allergies in the past.
• Woman who is pregnant, breast-feeding on day of enrollment, or become pregnant during the next 12 months
• Any acute fever disease or infections.
• History of SARS
• Major congenital defects or not well-controlled chronic illness, such as asthma, diabetes, or thyroid disease.
• Serious cardiovascular diseases, such as arrhythmia, conduction block, myocardial infarction, severe hypertension without controllable drugs, etc.
• Hereditary angioneurotic edema or acquired angioneurotic edema
• Urticaria in last one year
• No spleen or functional spleen.
• Platelet disorder or other bleeding disorder may cause injection contraindication
• Faint at the sight of needles.
• Prior administration of immunodepressant or corticosteroids, antianaphylaxis treatment, cytotoxic treatment in last 6 months.
• Prior administration of blood products in last 4 months
• Prior administration of other research medicines in last 1 month
• Prior administration of attenuated vaccine in last 1 month
• Prior administration of inactivated vaccine in last 14 days
• Current anti-tuberculosis prophylaxis or therapy
• According to the judgement of investigator,various medical, psychological, social or other conditions, those could affect the subjects to sign informed consent.