Evaluate Safety of GCFLU® Administered Intramuscularly in Healthy Vietnamese Volunteer Aged From 3 Years Old

Inclusion Criteria: Subject must meet all criteria below to participate in study 1. A person who is a 3-year-old or older, healthy and can be followed up for 21 days 2. Subject who gave voluntary written consent to participate in the study, and able to comply with the study requirements. With subjects aged from 3 years to below 18 years, parents/legal representative will give voluntary consent to participate in this study, and subjects from 12 to under 18 years old will give voluntary written consent for children. Exclusion Criteria: Subject have one of criteria below must not participate in study 1. Subject with a known hypersensitivity or allergic reaction to eggs or eggs products, to chicken or chicken products, to any component of the study vaccine, neomycin or gentamicin. 2. Subjects with immune system disorder including immune deficiency disease. 3. Subjects with a history of Guillain-Barre syndrome. 4. Subjects with severe chronic disease (e.g.; cardiovascular disease except for controlled hypertension, respiratory disease, metabolic disease, renal/kidney dysfunction or hemoglobinopathy etc.) who in the investigator's opinion may have a difficulty in participating in the study. 5. Subjects with hemophilia or receiving a treatment with an anticoagulant, who are at increased risk of serious bleeding during intramuscular injection. 6. Subject who had acute fever with body temperature exceeding 37.50 Celsius (armpit calculated) before vaccination with the study drug. 7. Subjects who had received other vaccination within 14 days before vaccination with the study drug, or those who had another vaccination scheduled during the study. 8. Pregnant women, breast-feeding women or women of childbearing potential who do not use an appropriate method of contraception (use of condom, intrauterine contraceptive device, or hormone contraceptives, or of a male partner had vasectomy). 9. Subjects who had participated in other clinical study within 28 days priors to vaccination with the study drug, or those who had another clinical trial scheduled during the study.