Weakened immune system and reduced effectiveness of certain vaccinations: Vaccines are designed to trick your body into creating antibodies that provide immunity to a particular disease or infection. But exhaustion compromises the immune system, so your body doesn't produce adequate antibodies, according to a study in which researchers administered hepatitis B vaccinations and measured patients' antibodies before and after treatment. People who slept fewer than six hours a night were the least likely to respond to the vaccine and were 11.5 percent more likely to emerge unprotected.
