Naturally acquired active immunity occurs when the person is exposed to a live pathogen, develops the disease, and becomes immune as a result of the primary immune response. Artificially acquired active immunity can be induced by a vaccine, a substance that contains the antigen.
The main cause of neck pain is tension. During periods of intense anxiety, your muscles tense up dramatically. Muscle tension tightens the muscles, especially in the shoulders, back, and neck. The more anxiety you experience, the more your tension may cause significant pain and discomfort. A related issue comes from the mindset of those with anxiety. Many people get muscle tension in their neck during times of stress.
What You Should Know About Neck Pain: Most new neck pain is from stretching and turning the neck muscles too much. Muscle overuse causes strained neck muscles. Looking up or to the side for too long is a common trigger. When muscle pain starts without reason, it's often from sleeping in an awkward position.