This study involves Shingrix, a vaccine used to prevent herpes zoster, which is commonly known as shingles. Shingles is a painful rash caused by the same virus that causes chickenpox, and it can occur in people who have had chickenpox in the past. The vaccine contains recombinant varicella zoster virus glycoprotein E, which is a protein made in a laboratory that helps the body build protection against the virus. The vaccine is given as an intramuscular injection, which means it is injected into a muscle.

The purpose of this study is to better understand how the immune system responds after receiving the recombinant herpes zoster vaccine. Specifically, the study will look at changes in certain immune system components that help fight the virus. These include cell-mediated immunity, which refers to immune cells that attack infected cells, humoral immunity, which involves antibodies that help neutralize the virus, and lymphocyte typing, which means identifying and counting different types of white blood cells that are important for immune defense. The study aims to examine a temporary change in specific immune responses that may occur after vaccination.

Participants will receive two doses of the vaccine given between two to six months apart. Blood samples will be collected at nine different times over a period of several months to measure how the immune system changes before and after each vaccine dose. The study will follow participants for approximately six months to track these immune responses over time. The measurements taken from the blood samples will help researchers understand the patterns of immune system activity following vaccination.