Evaluation of immunogenicity and safety of inactivated COVID-19 vaccine (BBIBP-Cov) coadministered with rabies vaccine.

The participants aged ≥18 who had received two doses of inactivated COVID-19 vaccine were recruited and randomly assigned to one of three study groups: Co-Ad group, COVID-19 vaccine group and Rabies vaccine group.

The participants in Co-Ad group and COVID-19 vaccine group received a booster dose of inactivated COVID-19 vaccine.The participants in Co-Ad group and Rabies vaccine group received three doses of rabies vaccine for pre-exposure immunization. The participants in Co-Ad group received the first dose of rabies vaccine (Day 0) and the inactivated COVID-19 vaccine simultaneously.

Any local or systemic adverse events after vaccination will be recorded.

Inclusion Criteria:

• Participants aged ≥18.
• Have the ability to understand the study procedures, voluntarily sign informed consent.
• Be able and willing to complete the entire study plan during the study follow-up period.
• Participants have not received any rabies vaccine.
• Participants have received 2 doses of inactivated COVID-19 vaccine for 6-12 months.
• The time interval between the last vaccination is ≥14 days.
• Body temperature < 37.3 °C confirmed by clinical examination before enrollment .

Exclusion Criteria for the first dose:

• Participants who have received the third dose of COVID-19 vaccine.
• Participants who have previously been infected with COVID-19 or who have tested positive for SARS-CoV-2.
• Having a history or family history of convulsions, epilepsy, encephalopathy and psychosis.
• Being allergic to any component of vaccines and a history of severe allergic reactions to any vaccine.
• Participants are suffering from immunodeficiency, receiving immunosuppressant therapy (oral steroid hormones) during treatment for malignancy, or having low immunity due to HIV within 14 days before enrollment, or having congenital immune disorders in close family members.
• Injection of non-specific immunoglobulin within 1 month before enrollment.
• Participants are suffering from acute febrile diseases and infectious diseases, or have used anti-inflammatory/antiviral/antipyretic/antiallergic drugs within 3 days before enrollment.
• A history of clearly diagnosed thrombocytopenia or other clotting disorders that may contraindicate subcutaneous injection.
• Participants with severe chronic diseases or acute episodes of chronic diseases, hypertension or diabetes that cannot be controlled by drugs.
• Participants with infectious, suppurative and allergic skin diseases.
• Pregnant and lactating women.
• Other Participants whose physical conditions, as determined by the investigator, are not suitable for inclusion in clinical studies.

Exclusion criteria for the second or third dose:

• Participants who had vaccine-related serious adverse reactions after vaccination.
• Systemic adverse reactions/anaphylaxis with severity ≥3 after vaccination as determined by the investigator.
• Participants experienced new conditions that met the "exclusion criteria for the first dose ".
• Other reasons for exclusion considered by the investigator.