“This unusually early case of influenza concerns me that everyone eligible to receive their flu vaccination should do it as soon as possible; flu is a really serious illness even for those who are relatively fit and well. "Vaccines should prevent you from catching the flu and reduce symptoms should you become infected. She added: "Secondary to getting your flu vaccination is prioritising your sleep. "Particularly prior to getting a vaccine; research suggests that a good night sleep before vaccination increases the chance you’ll make a good immune response. "The power of good sleep should not be underestimated.