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.
This kind of tight sore neck is often caused by a minor muscle strain and typically calms down after a few days of resting and being more careful with the neck and upper body. However, neck and shoulder pain can be more serious than just a simple wry neck from spasm of the neck muscles. When the shoulder and neck pain and muscle spasm of a pinched nerve does not show signs of improvement within a few days it then becomes important to seek professional help.