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.
People also viewed. 1  Talk to a doctor live online for free. 2  Tightness in lower right back. 3  Tight feeling in lower back.  Tightness in lower left 1  back. Ask a doctor a question free online.  Tight back muscles 1  causes. Causes of tightness in back of 2  neck. Tight glutes lower back  pain. Tight hips and lower back pain.