Which part of the body must influenza-B virus reach in order to survive?

Influenza-B virus has to reach the respiratory system to survive. The respiratory system is the primary site of infection for influenza viruses, including influenza B. The virus enters the body through the nose or mouth and travels down the respiratory tract, where it infects the cells of the nose, throat, and lungs. The virus replicates within these cells, causing the symptoms of influenza, such as fever, cough, sore throat, and runny nose.