S.H.
With vaccines, the Doc or nurse should have given you an information fact sheet. Did they give you one?
On this sheet, will be, all the details of the vaccine/mist.
And side effects etc.
IF they did not give you an information fact sheet about it, then simply go online and you can get it there.
Both my kids, get the Flu mist.
They have not ever, had side effects.
However, symptoms like your son, is not to me, the "Flu." It is his body, building up antibodies to the inoculation. And this is a sometimes common reaction to it. It shouldn't last longer than a couple of days.
Read the info fact sheet.
Or go to www.flu.gov.
And here:
http://www.flumist.com/prevent-the-flu?search=1&dbsrc...