Why is it called H1N1? How is it different from H5N1? Here is an explanation of flu virus names and types.
Influenza can seem a very complex virus, until you understand what the names mean and why they are used. First, lets get the complicated scientific names out of the way. Influenza is an RNA virus of the order Mononegavirales and the family Orthomyxoviridae. There are three types, known simply as Influenza A, B and C.
The rest is simple, for the most part. Influenza A affects birds, a number of mammals, and humans. B affects seals and humans, and C affects pigs and humans. Influenza C can occasionally be serious but is mostly mild and we don’t worry about it. Influenza B is mild too, but can cause an epidemic, though not a dangerous pandemic. Influenza A is the overall virus that all the dangerous subtypes belong to.
Influenza A Naming of Parts
The virus is usually round with a number of surface proteins, which are either hemagglutinin or neuraminidase. These are the H and N of the flu virus and their position gives the number part of the name. Within the flu molecule are other proteins and when medical experts and researchers discuss the mutations that the flu virus demonstrates they will mention other components of the virus.
These include the NP gene, a nucleoprotein that is peculiar to each type (A,B or C), the M gene, either the matrix protein M1, or an ion channel that spans the cell wall, M2. The NS gene will be found not in the virus itself, but in the cell it infects. Finally the RNA molecule will be a subunit of RNA polymerase, called PA, PB1 or PB2.
Each of these allows further understanding of how the virus mutates and, more importantly, each represents an opportunity to create a vaccine or treatment for influenza.
Influenza Identification by Time and Location
The pandemic of 1918 was called the Spanish Flu, although it did not originate in Spain and the virus had not been isolated at the time. To identify the various types of influenza that infect both animals and humans a system of naming strains has been established, which has been used since the 1950s.
The system follows the convention ‘type, location, ID, year, subtype,’ to give: A/Hong Kong/156/97 (H5N1). This system allows the global network of medical researchers and vaccine developers to know which exact strain of virus they are dealing with, and the flu vaccines that we are all recommended to get are usually a combination of inactive virus strains that are the most prevalent and most dangerous. The avian flu had an additional section in its name. HPAI stands for highly pathogenic avian influenza, and means death occurs in over 50% of those falling sick with the virus.
Influenza Vaccine 2011
The vaccine that has been prepared for the flu season of 2016 to 2017 is a combination of the following strains:
A/California/7/2009 (H1N1)-like virus
A/Perth/16/2009 (H3N2)-like virus
B/Brisbane/60/2008-like virus.
Inactive virus components are introduced to your body either through injection or nasal spray and within two weeks you should have built up enough antibodies to protect you from the above strains of influenza and several mutations of these.
Health organizations are hoping that enough people are vaccinated to protect those who cannot receive the vaccination, whether because of age or immune-deficiency. Herd immunity is the term given to the majority of a population having an immunity to an infection so it cannot get a foothold within the community. Join the herd and get your flu vaccination. It could save more than one life.
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