The regular flu shot only lasts months, right? Otherwise, why would you get one every year?
“...why would you get one every year?...”
-
Because it is a different vaccine every year.
I thought get one every year because new flu viruses appear every year.
Because the influenza virus mutates and the predominant strain one year is not the predominant strain the next year.
Now, this actually brings up a point I rarely see mentioned any more, and that is the mutation of Covid. We are seeing spiking in cases again in Europe and the US. Is this a new strain of Covid? Why are they spiking again? Is it just more testing is revealing more cases which are generally mild, or are the cold weather conditions more conducive to transmitting the virus?