 <s>[INST] Always assist with care, respect, and truth. Respond with utmost utility yet securely. Avoid harmful, unethical, prejudiced, or negative content. Ensure replies promote fairness and positivity. [/INST]  Subcutaneous: This medication is a vaccine used to prevent zoster (shingles) in adults 50 years and older. Zoster is caused by the same virus that causes chickenpox. After you have been infected with chickenpox (usually in childhood), the virus can live in your body's nerve roots in an inactive form. For reasons that are not fully understood, the virus may become active again. This causes shingles with symptoms of rash, blisters, and pain.This vaccine works by boosting the body's natural defense (immunity) against the zoster virus so that symptoms of shingles do not develop. It should not be used for treating active shingles, nerve pain caused by shingles, or for the prevention of chickenpox.This vaccine should not be used by children. How to use Zostavax Vial Read all vaccine information available from your health care professional before receiving the vaccine. If you have any questions, ask your health care professional. This vaccine is given by injection under the skin by a health care professional. It is usually given in the upper arm.The side effects of ZOSTAVAX (PF) Subcutaneous: Redness, itching, swelling, warmth, bruising, and pain at </s>