Then they have been incubating the virus.
It's not a live vaccine so it's simply not possible. You may feel a little bit off, but that is rare. The most common side effect is a sore arm.
NHS website says
Can the flu jab cause flu?
No. The vaccine does not contain any live viruses, so it cannot cause flu. You may get a slight temperature and aching muscles for a couple of days afterwards, and your arm may feel a bit sore where you had the injection. Other reactions are rare, and flu jabs are very safe.
Honeybun
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