The information i have from the pharmacist at the Chemists is that if I have one of the "old" strains that were included in both the 2016 and 2017 vaccine I will have an element of resistance.
So it is either that, or just "man flu", as we all know there is no cure for that....
But if I had a flu strain that is not covered with the vaccine I would be exactly as you describe, and with my lung damage, possibly be in hospital. It can kill, particularly the young, as the poor lass in Scotland found out. Just 18.
But we are, hopefully, a long long way from the 1919 H1N1 strain.
