It is also possible that the vaccine may not be properly stored or administered, or that the animal may have an unusually weak immune response. (newscientist.com)
Couples with marital conflicts have greater difficulty with wound healing and an overall weaker immune response. (positivepsychologynews.com)
The researchers found that the older subjects exhibited weaker immune responses, as there was less T cell activation, and less reddening and swelling of the skin. (sciencedaily.com)