Influenza Incubation Period
The incubation period for any disease is the interval between exposure to the disease-causing agent and the onset of symptoms. The influenza virus has a nearly two-day incubation period, which typically ranges from one to four days. Two days is a typical growth period for a virus that multiplies swiftly and makes multiple copies. One to four days after the virus replicates in the human body, the symptoms of influenza infection begin to manifest. People who are already infected with influenza are contagious for approximately 5 to 7 days after the onset of their symptoms.
