Influenza-B Florida

Influenza B Virus Florida 07/04 is a strain of the Influenza B virus, which belongs to the Orthomyxoviridae family. Unlike Influenza A, which infects a wide range of hosts, Influenza B primarily infects humans and seals . This strain is part of the broader category of Influenza viruses that cause seasonal flu epidemics.

The Influenza B virus has a multipartite genome consisting of eight segments of linear negative-sense, single-stranded RNA. Each segment is encapsidated in a separate nucleocapsid, surrounded by an envelope . The genome is approximately 14,648 nucleotides long and encodes several proteins essential for the virus’s replication and infectivity.

The virion of Influenza B virus is enveloped and can be either spherical or filamentous. It has about 500 surface projections made up of hemagglutinin (HA) and neuraminidase (NA) proteins . These proteins play crucial roles in the virus’s ability to infect host cells and in the release of new viral particles.

Influenza B virus evolves slower than Influenza A but faster than Influenza C. It mutates at a rate 2-3 times lower than type A viruses . Despite this slower mutation rate, Influenza B still changes enough that lasting immunity is not possible, necessitating annual updates to the flu vaccine.

The Influenza B Virus Florida 07/04 strain was isolated from allantoic fluid of 10-day-old embryonated eggs. The virus was purified using ultracentrifugation with a 10-40% sucrose gradient . This method ensures a high purity level, greater than 90%, as determined by SDS-PAGE.

The virus is inactivated using thimerosal and beta propiolactone treatment . These treatments ensure that the virus is safe for laboratory research use. The inactivated virus is typically stored in a sterile, filtered colorless solution containing STE, 0.09% sodium azide, and 0.005% thimerosal .

Research reagents derived from the Influenza B Virus Florida 07/04 strain, such as proteins, antibodies, and cDNAs, are widely used in virology research . These reagents help scientists study the virus’s structure, function, and interaction with host cells, contributing to the development of vaccines and antiviral drugs.