Influenza vaccination is recommended for all travellers over 6 months of age, especially for children, pregnant women, persons over 65, and those with chronic health conditions such as asthma, diabetes, lung disease, heart disease, immunosuppressive disorders, and organ transplant recipients.. Note: In the northern hemisphere the flu season typically runs from November to April. In the southern hemisphere, it runs from April to October, and year-round in the tropics. ...