What are parainfluenza viruses (PIVs)?
Human parainfluenza virus is single-stranded RNA virus which infects infants and young children. This influenza-causing virus has four distinct types namely HPV-1, HPV-2, HPV-3 and HPV-4. HPV is different from influenza virus. HPV infects in fall and spring whereas influenza virus infects in winter. It mainly presents with fever, cough and runny nose. Influenza shot does not protect you from parainfluenza.