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.
The cause of the muscle spasm lies in the fact that the bulging disc is pressing against the ligament that holds it in place. Since this ligament contains nerves, the result is pain.Because of the initial pain, the back muscles go into spasm as part of the body's effort to immobilize the painful area.he cause of the muscle spasm lies in the fact that the bulging disc is pressing against the ligament that holds it in place. Since this ligament contains nerves, the result is pain.