All of your art work is delightful so it is always our pleasure to use it.
And in this case, we had to use something that was not specific to needles, because some people can react even to photos of their phobia, which is very understandable.
It sounds like your husband is having the fainting reflex (vasovagal). Whenever possible, he simply needs to avoid watching when other people (or animals) are getting shots. If it is unavoidable, he needs to sit down or preferably lay down before either he or anyone else gets a shot. He won't be able to talk himself out of it; it is simply a physical reaction.