One more consideration on the injections -
most needles (not all) are coated with silicone. Some animals are
sensitive to this and can have a reaction. Remember though that this is a
very tiny amount of silicone in relation to a large animal but some are very
sensitive.
I'm glad to see Susan remind everyone that
some swab the injection site with alcohol and some don't. It is virtually
impossible to sanitize skin. Look at how much trouble surgeons go to
before surgery!
All in all, vaccines are a very good
thing. Sometimes it's hard to accept that we have an animal that may have
reacted to something other than the actual vaccine (the carrier, the silicone,
the dirt on the needle, etc., etc.) I am in no way downplaying the
seriousness of some folks' horses reactions. But as someone with dairy
cattle who vacinnates on a regular schedule, I've seen some terrible results to
farms who don't. I'll gladly accept the tiny possibility that some
reactions may occur. And have.