The subjects would be randomly divided into three groups of 60 subjects each. Group1 receives a single intramuscular dose of 0.5 ml of trivalent influenza vaccine, containing at least 15 microgram of hemagglutinin antigen per strain, Group II receives two-site intradermal dose of 0.1 ml each, containing at least 3 microgram of hemagglutinin antigen per strain per site and group III receives two-site intradermal dose of 0.2 ml each, containing at least 6 microgram of hemagglutinin antigen per strain per site. Check for HA Antibody