"Influenza Reinfection in Humans"

Influenza reinfection in humans occurs when someone who has previously caught the flu gets infected again at a later time. This can happen because the flu virus constantly changes its structure through mutations, making previous immunity less effective. Factors like a new virus strain, weakened immune response, or incomplete recovery can increase the risk of reinfection. Reinfections tend to happen seasonally, especially when new flu variants emerge. Vaccination and good hygiene practices can reduce the chance of catching or spreading the flu again, but reinfection remains a possibility due to the virus's ability to evolve rapidly.