Why we do not have a universal one time vaccine for the Flu virus?
We know that Polio disease caused by the Polio virus is now completed eradicated from approx all parts of the world. Similar is the case for Mumps, measles etc.
These diseases are completely eradicated because of the development of their universal vaccine. Their vaccines are generally given to the children during early age, and they remain protected from these viruses for lifetime.
But, this is not the case for Influenza virus (more commonly called the Flu virus).
Flu virus’s outer structure changes continuously, so our immune system is unable to recognize every time during multiple encounters.
Hence, it is challenging to make a universal one-time vaccine for the Influenza virus or the Flu virus.
Scientists are currently working on understanding the behavior of the immune system during the change in outer structure of the flu virus, and also its inner complex structure.
Also read General information on CORONAVIRUS Pandemic 2020 (COVID-19) with full fact based genuine references.