Effect of Obesity on Immune Response to Pneumovax 23

Pneumococcal infections are a leading cause of adult and childhood hospitalization and death. It has been shown that obese individuals are at higher risk for this bacterial infection. As a result, investigators will vaccinate obese individuals to see if they are offered the same level of protection from the vaccine as normal-weight individuals. The vaccine used for this particular bacterial infection is called Pneumovax 23. The purpose of this study is to compare how body mass index affects protection that the vaccine provides against these bacteria. Primary Hypothesis: Levels of protection from the vaccine are no different in pre- and post- vaccination in healthy BMI individuals and obese individuals.