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
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.
- 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
- 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
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
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
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
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
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
1. Any severe side effects from vaccines
2. Allergic reaction to phenol
1. Taking any antioxidant supplements (EmergenC)
2. Unable to refrain from antioxidant supplements throughout the duration of the