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.
Any abnormalities, inflammation, or injury can cause neck pain or stiffness. Many people experience neck pain or stiffness in the neck occasionally. In many cases, it is due to poor posture, normal wear and tear, or overuse. Sometimes, neck pain is caused by injury from a fall, contact sports, or whiplash.