Active and Passive Immunity. 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.
Lower back tightness can cause muscle twitching, pain and reduced range of motion. Lower back muscle tightness is the cause of a muscle spasm. This can be brought on by a strain, overuse or muscle weakness, according to BetterMedicine.com.
Causes of Back muscle pain (Sore back muscles). The list of medical condition causes of Back muscle pain (Sore back muscles) includes: 1  Arthritis. 2  Osteoporosis. 3  Sciatica. 4  Tuberculosis. 5  Stress.