The purpose of this study is to evaluate the safety and immunogenicity of concomitant administration of EV71 vaccine with measles mumps, and rubella combined live attenuated vaccine/ encephalitis live attenuated vaccine.

This study is an open-label, single-center, randomized, comparative phase IV clinical trial. The purpose of this study is to evaluate the safety andimmunogenicity of concomitant administration of EV71 vaccine manufactured by Sinovac (Beijing) Vaccine Technology Co., Ltd. with measles mumps, and rubella combined live attenuated vaccine/ encephalitis live attenuated vaccine. 360 healthy infants of 8 months old as participants are randomly assigned into three experimental groups in the ratio 1:1:1. The group I receive EV71 Vaccine (first dose)&measles mumps, and rubella combined live attenuated vaccine on day 0 and EV71 vaccine (second dose)&encephalitis live attenuated vaccine on day 30. The group II receive measles mumps, and rubella combined live attenuated vaccine on day 0 and encephalitis live attenuated vaccine on day 30. The group III receive the first and second dose of EV71 Vaccine on day 0 and day 30 respectively.

Inclusion Criteria:

• Healthy volunteer aged ≥ 8 months;
• Proven legal identity;
• Guardians of the participants should be capable of understanding the written consent form, and such form should be signed before the infant being included into this study.

Exclusion Criteria:

• Prior vaccination with EV71 vaccine;

• Prior vaccination with MMR vaccine or vaccine including mumps or measles or mumps or rubella vaccine components;

• Prior vaccination with Encephalitis B vaccine；

• Cannot be vaccinated with both arms at the same time；

• History of hand，foot and mouth disease;

• History of measles or mumps or rubella or encephalitis B；

• Allergy to gentamicin; history of allergy to any vaccine or vaccine ingredient, or serious adverse reaction(s) to vaccination, such as urticaria,difficulty in breathing, angioneurotic edema, pain, etc;

• Congenital malformations or developmental disorders, genetic defects, severe malnutrition, etc;

• Autoimmune diseases or immunodeficiency/immunosuppression;

• Severe neurological disorders (epilepsy, convulsions or convulsions) or psychosis;

• History of thyroidectomy, absence of spleen, functional absence of spleen, and any circumstances leading to absence of spleen or splenectomy;

• Diagnosed coagulation function abnormal (e.g., coagulation factor deficiency, coagulation disorder, or platelet abnormalities) , or obvious bruising or coagulation disorders;

• Any immunosuppressant, cytotoxic medicine, or inhaled corticosteroids (except corticosteroid spray for treatment of allergic rhinitis or corticosteroid treatment on surface for acute non-complicated dermatitis) in the past 6 months;

• Receipt of any of the following products:

  1. Blood product within 3 months prior to study entry;
  2. Any live attenuated vaccine within 14 days prior to study entry;
  3. Any subunit vaccine or inactivated vaccine within 7 days prior to study entry;
  4. Any other study drugs within 30 days prior to study entry;

• Acute disease or acute stage of chronic disease within 7 days prior to study entry;

• Axillary temperature > 37.0#;

• Any other factor that suggesting the volunteer is unsuitable for this study based on the opinions of investigators.