One of the reasons the flu is so difficult to prepare for is because it is a constantly changing virus.
When we use the word strain what we’re describing is flu viruses that are antigenically (meaning to induce a specific immune response and reacting with the products in accordance with that response) different.
There are so many chemical combinations that could bond together to create varying influenza viruses, all antigenically different from one another that the exact number of ‘strains of flu’ is in the thousands – and that’s just looking at humans strains, not swine or other animal based influenza viruses.
Another way to tell the difference between flu virus is by their flu subtype.
Ian York, Virologist, immunologist and biologist explained that the two subtypes of flu, “are be defined by the hemagglutinin (HA) and neuraminidase (NA) proteins on their surface because these are the dominant proteins in the immune response to flu.”
Each year, experts asses what mutation of the flu are circulating and/or predicted to circulate and direct vaccination advise accordingly.
2017 Seasonal Influenza Strains
This year Nurse Practitioner Clinics Australia have released the following information:
“The recommended composition of quadrivalent influenza vaccine for Australia in 2017 introduces a new A (H1N1)pdm09 like virus strain when compared to the composition of the trivalent and quadrivalent vaccines for Australia in 2016.”
“In 2017 there will only be Quadrivalent Influenza Vaccines available in Australia. This will be the first time that the Trivalent Vaccine will not be available to the Australian market (either public or private)”
The quadrivalent influenza vaccine components for the Australian 2017 influenza season will contain the following:
An A/Michigan/45/2015 (H1N1) pdm09 – like virus
An A/Hong Kong/4801/2014 (H3N2) – like virus
A B/Brisbane/60/2008 – like virus (belonging to the Victoria lineage)
A B/Phuket/3073/2013-like virus
What’s in the flu shot?
The flu vaccines available in Australia are all made from highly purified egg-grown influenza viruses, which are then killed and broken up into tiny pieces.
Small amounts of preservative and stabiliser may be used, depending on the individual manufacturers production process.
When the vaccine is injected, the body is fooled into believing it has been invaded by the virus, and produces an immune response. This kind of inactivated vaccine cannot cause influenza in the recipient.
DISCLAIMER: This is in no way gives you any flu symptoms, people. Like, NONE.
