This study is a randomized, controlled, open-label phase Ⅳ clinical trial of a live attenuated mumps vaccine manufactured by Sinovac (Dalian) Vaccine Technology Co., Ltd. The purpose of this study is to evaluate the immunogenicity and safety of the booster doses of a mumps vaccine administrated alone and concomitantly with a quadrivalent inactivated influenza vaccine in healthy junior high school students. And the cross-neutralization of mumps vaccine immune serum and mumps virus strains

This study is an open-lable, randomised, controlled phase Ⅳ clinical trial in healthy junior high school students to the immunogenicity and safety of the booster doses of a mumps vaccine (MV) administrated alone and concomitantly with a quadrivalent influenza vaccine (QIV) in healthy junior high school students. The experimental vaccine was manufactured by Sinovac (Dalian) Vaccine Technology Co., Ltd. A total of 400 healthy students will be enrolled, including 300 students who have received one dose of mumps-containing vaccine (MCV) before vaccination, and 100 students who have received two doses of mumps-containing vaccine before vaccination. 300 students with a history of 1 dose of MCV will be randomly divided into 3 groups in a ratio of 1:1:1, and will receive 1 dose of MV alone, 1 dose of QIV alone, or 1 dose of MV and 1 dose of QIV simultaneously. Students with a history of 2 doses of MCV received 1 dose of MV alone. Blood samples were collected before and 30 days after vaccination. Pre-vaccination blood samples were used to detect antibody levels of measles, mumps, influenza and varicella, and post-vaccination blood samples were used to detect mumps antibodies and/or influenza antibodies corresponding to the vaccination.

Inclusion Criteria:

• Healthy junior high school students;
• subjects and/or guardians who can understand and voluntarily sign the informed consent form (For subjects aged 8-17 years, both subjects and guardians need to sign the informed consent form)
• Provision of valid identification.;
• History of 1 or 2 doses of mumps-containing vaccine;

Exclusion Criteria:

• History of mumps or have completed 3 doses of mumps-containing vaccine;
• Receipt of the current seasonal influenza vaccine (except subjects in Arm 4)
• History of asthma or allergy to the vaccine or vaccine components, or serious adverse reactions to the vaccine, such as urticaria, dyspnea,and angioedema;
• Congenital malformations or developmental disorders, genetic defects, severe malnutrition;
• Autoimmune disease (such as systemic lupus erythematosus) or a state of immunodeficiency / immunosuppression (such as AIDS, after organ transplantation);
• Severe chronic diseases, severe cardiovascular diseases, hypertension and diabetes that cannot be controlled by drugs, liver or kidney diseases, malignant tumors, etc.;
• Severe neurological disease (epilepsy, convulsions or convulsions) or mental illness;
• Thyroid disease or history of thyroidectomy, asplenia, functional asplenia, any condition resulting in asplenia or splenectomy;
• Abnormal coagulation function diagnosed by a doctor (such as coagulation factor deficiency, coagulation disease, platelet abnormality) or obvious bruising or coagulation disorder;
• Immunosuppressive therapy, cytotoxic therapy, inhaled corticosteroids (excluding corticosteroid spray therapy for allergic rhinitis, topical corticosteroid therapy for acute uncomplicated dermatitis) within the past 6 months;
• Receipt of blood products in the past 3 months;
• Receipt of other investigational drugs in the past 30 days;
• Receipt of attenuated live vaccines in the past 28 days;
• Receipt of inactivated or subunit vaccines in the past 7 days;
• Onset of various acute or chronic diseases within 7 days prior to the study;
• Axillary temperature >37.0°C;
• Participation in other clinical trials before enrollment and during the follow-up period, or a plan to participate in other clinical trials within 3 months.
• Any other factors that are unsuitable for participating in this clinical trial according to the investigator's judgment