Influenzavirus A
Influenzavirus B
Influenzavirus C
Isavirus
Thogotovirus

The Orthomyxoviridae are a family of RNA viruses which infect vertebrates. It includes those viruses which cause influenza.

Influenzavirus B is a genus in the virus family Orthomyxoviridae. The only species in this genus is called "Influenza B virus".

Influenza B viruses are known to infect humans and seals, giving them influenza.

The annually updated trivalent flu vaccine consists of hemagglutinin (HA) surface glycoprotein components from influenza H3N2, H1N1, and B influenza viruses.

Sources

• International Committee on Taxonomy of Viruses - 46.0.4. Influenzavirus B
• Influenza A (H3N2) Outbreak, Nepal annually updated trivalent vaccine contents listed
• Influenza B virus in seals

Further reading

• Emergence of an Influenza B Virus with Antigenic Change

Viruses | Influenza