Credit: National Geographic
Why does an influenza vaccination only work for one year? Others work for years, even a lifetime.
Existing vaccines work by "teaching" the immune system to recognize proteins in the coat which surrounds the virus. Once the immune system is able to recognize the virus by its coat, it can attack & destroy it.
Unfortunately, the rate of mutation in the proteins in the coat is very high. This means that if you are immune to last year's influenza virus (i.e. your immune system can recognize the proteins in the coat of the virus), this year's virus will have a protein coat so different that you immune system can't recognize it.
Result? A new vaccination is required each year.
http://theconversation.com/the-holy-grail-of-influenza-research-a-universal-flu-vaccine-14046 / flu shot protect pandemic yearly seasonal flu viruses circulation identify jackets jacket immune system influenza virus interact regognise immune system intruders viruses bacteria bacterium viri virii influenza outer coat proteins virus called hemagglutinin HA neuraminidase NA proteins change mutate proteins recognise virus mount defence mutations viral coat proteins influenza vaccine formulations changed frequently vaccination is recommended every year yearly targets universal influenza vaccine educating immune system less easily fooled small types influenza viruses lifetime types influenza infect humans type A B seasonal influenza vaccines comprise both types strategies influenza A complex subdivided subtypes reactivity specific tests antigen antigenicity genetic similarity hemagglutinin neuraminidase 2009 H1N1 pandemic influenza H7N9 strain infecting infection China epidemic universal influenza vaccine more broadly cross-protective cross protective vaccine against more than one strain of influenza A /
