effect of obesity on immune response to pneumovax 23

Conditions: Obesity

Summary: 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.

study participants: for this study, the investigators will recruit 56 participants separated into two groups. group 1 will enroll 23 individuals with a bmi between 22 and 25. group 2 will enroll 23 obese individuals. study participants will be between the ages of 18-35 and in good health. pre-screening: basic eligibility will first be determined by phone or through a questionnaire. the investigators will acquire weight and height information to calculate bmi, as well as ask about any chronic health problems. at the end of the pre-screening, an email address will be requested in order to email a copy of the consent form for the participant to review before the first visit, during which the consent form will be reviewed with the participant and any questions addressed. a cell phone number will also be requested to text participant reminders the night before their appointments (visit 1 and visit 2). if the participant declines a reminder text, a reminder phone call will be set-up. screening: during the in-person screening, the investigators will ask several questions. participants with chronic health problems (significant vascular disease, hepatitis, renal disease, diabetes, immunodeficiency) will be excluded. individuals already immunized with pneumovax23 or prevnar (another vaccine that protects against pneumococcal infection) will also be excluded. a pregnancy test will be given to females to exclude pregnant individuals. an hba1c (finger prick to get a drop of blood) will also be performed to exclude participants with high blood sugar levels. physical exams will be performed and vitals will be taken on participants who pass the initial screening to help assess health. questionnaires will also be given at the first visit to assess stress, which has been shown to affect the ability to protect against infection. study visits: all participants will receive a pneumovax 23 vaccine, questionnaires, physical exams, and undergo 2 blood draws. part of the blood will be sent to a research laboratory for gene analysis. this will help us determine if certain genetic markers explain individual differences in pneumovax 23 efficacy.

Eligibility criteria:
inclusion criteria: control group * aged 18-35 * bmis between 22-25kg/m2, obese group * aged 18 - 35 * bmis greater than 30kg/m2, and * waist to hip ratio of at least 0.9 in males and at least 0.85 in females exclusion criteria: * pregnancy: pregnant, planning to become pregnant, or breastfeeding * diabetes mellitus (a1c\> 6.5%): diagnosed with diabetes * abnormal cmp and cbc values as determined by the principal investigator. * inability to fast for 8 hours prior to the initial blood draw * immunization: immunized with pneumovax 23, or immunized with prevnar * medications:currently taking any of the following medications or within the 4 weeks of study: i. immunosuppressive drugs or chemotherapeutic agents such as azathioprine, mycophenolate mofetil, tnf inhibitors, cyclosporine, methotrexate, leflunomide, cyclophosphamide, sulfasalazine, antimalarial drugs, chlorambucil, nitrogen mustard ii. steroids such as prednisone, cortisone, hydrocortisone iii. antidiabetic drugs such as metformin, insulin, glipizide, meglitinide, sulfonylurea, glimepiride, repaglinide, nateglinide * history of clinical illness (exclusion during clinic) 1. pneumonia or previously had pneumonia 2. low blood pressure or experienced dizzy spells 3. significant cardiovascular disease:recently hospitalizations deemed significant at the discretion of the principal investigator, or history of heart attack, or history of stroke 4. spleen, splenectomy, or damage to spleen 5. lung disease or history of lung disease 6. kidney disease, blood in urine, or protein in urine 7. liver disease, previous or current liver diseases such as hepatitis a, b, or c, liver cirrhosis, or autoimmune hepatitis, or elevated ast/alt lab test 8. leukopenias 9. hemoglobinopathies, history of sickle cell disease, or thalassemia 10. hiv/aids, or a history of hiv infection 11. recreational iv drug use, or intravenous drug injection predisposes users to infections, such as human immunodeficiency virus, that may alter the immune system and therefore affect the immunoglobulin response to pneumovax23. 12. history of iv-drug use, or iv drug use is a risk factor for hiv infection, which may change the immune response to pneumovax 23. 13. history of idiopathic thrombocytopenic purpura 14. history of chronic inflammatory diseases such as rheumatoid arthritis or chronic granulomatous disease 15. autoimmune disease 16. immunodeficiencies: neutropenia, common variable immune deficiency, bruton's x-linked agammaglobulinemia; scid; selective iga deficiency; wiskott-aldrich syndrome; ataxia telangiectasia; digeorge syndrome; chronic granulomatous disease; hyper ige syndrome; complement deficiencies * weight 1. planning on losing weight within the time frame of the study 2. have experienced excessive weight loss or gain within two months prior to the study 3. planning to undergo liposuction, gastric bypass, stomach stapling, whipple procedure, or reconstructive surgery involving transplantation of adipose tissue within the study period 4. bodybuilder or someone who takes part in excessive weight training * allergy 1. any severe side effects from vaccines 2. allergic reaction to phenol * medications/supplementations 1. taking any antioxidant supplements (emergenc) 2. unable to refrain from antioxidant supplements throughout the duration of the study.

Keywords: pneumovax23 obesity