The virus is spread from person to person by direct contact and by air-born droplets. Unlike the viruses that cause the cold, we can fight influenza A virus with both vaccinations and anti-viral medications. Signs and Symptoms. For 48 hours after exposure, the virus replicates and spreads throughout your body. The onset of symptoms is rapid, with high fever and chills.
Muscle aches in the back and legs, and headaches are common.
Later the throat, lungs, nose and eyes become affected. The cough can be severe and produce colored sputum. The illness usually begins to resolve in two to three days. Cough can persist for weeks. In persons who are very young, very old, or have lung disease, pneumonia and bloody coughing can develop.