Vaccines in adults in preventing or minimising the burden of infections are crucial to the well being of the individual. As you grow older the immune system begins to slow down. This slowing is not only due to age but also due to exhaustion, fatigue, disease and lifestyle besides other factors. That is why the vaccine is a support to your body since one major element called memory is depleted.
Once you take a vaccine, it is introducing a foreign body into your system. This is also called an antigen and is programmed to induce an antibody reaction from your immune system. This process is then recorded in a subset of cells called your memory T cells. This memory then becomes active when your system is exposed to the same assault, say for instance influenza. If you, therefore have three to four, or more, severe attacks of the flu every year, the vaccine reduces the burden of the viral shedding and consequently the duration of symptoms and severity.
Different vaccines are prescribed depending upon your requirements. The influenza and the pneumococcal vaccines are indicated in high risk individuals and those with structural lung disease. The Hepatitis B vaccine is specifically for those who deal with infected body fluids like healthcare workers. The human papilloma virus vaccine is crucial in preventing cervical cancer. These are some examples of vaccine preventable conditions.
Not every vaccine is suitable for everyone. There are live attenuated vaccines, killed vaccines, besides others. You need one which is best suited to you.
You therefore need to tailor your requirements depending on your risk, age, and other factors. Preventive aspects of Infections are far more vital than treating an already established one.