Flu 2025 Symptoms Ukraine. The infection may progress quickly to severe respiratory illness and neurologic changes (altered mental status or. Type a influenza is a common infection that can cause widespread flu outbreaks.
Both infections are caused by viruses, but their effect on individuals can vary. Trivalent flu vaccines are formulated to protect against three flu viruses (an a(h1n1) virus, an a(h3n2) virus, and a b/victoria virus).