The Virus Structure

---

Schematic Model for Influenza Virus Particles

The center or core of the influenza virus contains genetic material called ribose nucleic acid or RNA. The influenza virus RNA contains all the genes necessary for the virus to survive and reproduce within host cells.

Each strand of the influenza virus RNA is covered with a protein coat called nucleoprotein.

The entire core of the virus is covered by another layer of material, called the matrix protein membrane. The matrix protein membrane in turn is covered by a fatty or lipid envelope. Two different types of protein molecules, called the hemagglutinin or H protein and the neuraminidase or N protein protrude through the fatty envelope like spikes. The H and N proteins help the influenza virus attach to and enter the cells which it infects. Your body recognizes these H and N proteins as foreign and attacks the virus by producing antibodies against them.

Scientists name viruses by their type (i.e., influenza A, B, or C), the place where the virus came from, the laboratory number, and the year it was collected. The influenza A virus is also named by the type of H an N proteins it carries and the animal it was isolated from, if not a person. For example, Influenza A/Sydney/5/97 (H3N2) is a human influenza A virus that came from Sydney, Australia, was isolated in 1997, and has type 3 H protein and type 2 N protein.