Influenza B Florida

Influenza B virus is a member of the Orthomyxoviridae family, which also includes Influenza A and C viruses. Unlike Influenza A, which infects multiple species, Influenza B primarily infects humans and seals. The strain Influenza B/Florida/04/2006 (B/Florida/04/06) was first isolated in Florida, USA, in 2006 .

The Influenza B virus has a segmented genome consisting of eight segments of linear negative-sense, single-stranded RNA. Each segment is encapsidated in a separate nucleocapsid, and the nucleocapsids are surrounded by an envelope. The virus is approximately 14,648 nucleotides long .

The surface of the Influenza B virus is covered with approximately 500 projections made of two glycoproteins: hemagglutinin (HA) and neuraminidase (NA). These proteins are crucial for the virus’s ability to infect host cells and for the release of new viral particles .

Influenza B viruses evolve more slowly than Influenza A viruses but faster than Influenza C viruses. The mutation rate of Influenza B is about 2-3 times lower than that of Influenza A. Despite this slower mutation rate, Influenza B still mutates enough to prevent lasting immunity, necessitating annual updates to the influenza vaccine .

The B/Florida/04/06 strain was isolated from allantoic fluid of 10-day-old embryonated eggs inoculated with the virus. The virus was then purified using ultracentrifugation with a 10-40% sucrose gradient. Inactivation of the virus was achieved using thimerosal and beta-propiolactone treatment .

The B/Florida/04/06 strain has been used in serological studies and as an immunogen for antibody production. It has been tested with anti-influenza B monoclonal antibodies in ELISA assays, demonstrating its utility in research and vaccine development .

Various reagents have been developed from the B/Florida/04/06 strain, including proteins and antibodies. These reagents are used in laboratory research to study the virus’s structure, function, and immunogenic properties. For example, hemagglutinin (HA) and nucleoprotein (NP) proteins from this strain are commonly used in research .