Not to seem like a wise guy, but who is "they", and is it at all possible that "they" were saying that to make your wife feel better about getting the shot, without actually knowing for certain?
I’ve read accounts of nurses giving the seasonal flu shot and insisting it was the pandemic version, or that it would give protection against pandemic flu.
Medical professionals are often very uninformed about what’s going on with the pandemic. One reason is the CDC and assoicated Public Health Departments are not necessarily transparent or forthcoming with truth. To find out what’s happening, a person whether a HCW or not, has to spend time and energy researching and looking stuff up.