Peanut Allergy Vaccine Study in Healthy and Peanut-allergic Adults

Inclusion Criteria: * Available for the duration of the trial * Ability to perform spirometry maneuvers * Agree to use effective methods of contraception for the duration of the study * For Step 1 participants, regular consumption of at least 5 grams of peanut at least twice per month during the last 6 months prior to study entry * For Step 2 participants, a convincing clinical history of peanut allergy and prick skin test positive to peanut. More information on these criteria can be found in the protocol. Exclusion Criteria: * History of any severe anaphylaxis * Known allergy to hydroxypropyl methylcellulose, glycerol, or phenol * Evidence of clinically significant immunosuppressive neurologic, cardiac, pulmonary, hepatic, rheumatologic, autoimmune, or renal disease * Laboratory evidence of liver or hematologic disease. Pre-existing history of autoimmune or antibody mediated diseases. More information on this criterion can be found in the protocol. * Pre-existing history of autoimmune or antibody mediated diseases. More information on this criterion can be found in the protocol. * Any previous intubation due to allergies or asthma * History of ischemic cardiovascular disease * Uncontrolled hypertension * Significant medical condition that, in the opinion of the investigator, would interfere with the study * Chronic diarrhea * Inability to refrain from anal intercourse for the duration of the trial * Use of rectal medications during the study * Planned rectal procedures for the duration of the study * History of rectal surgery or bleeding in the last 6 months prior to study entry * History of proctitis in the last 6 months prior to study entry * History of inflammatory bowel disease, celiac disease, or eosinophilic esophagitis/gastroenteritis * Participation in another investigational vaccine or drug trial within 30 days prior to study or while the study is ongoing * Medical, occupational, or family problems as a result of alcohol or illicit drug use during the last 12 months prior to study entry * FEV1 value less than 80% predicted * Inability to discontinue antihistamines for skin testing * Currently on any allergy immunotherapy * Participation in any interventional study for the treatment of food allergy in the past 12 months prior to study entry * Poor control of persistent activation of atopic dermatitis * Use of omalizumab or other non-traditional forms of allergen immunotherapy or immunomodulatory therapy or biologic therapy within the past 12 months prior to study entry * Use of oral B-blockers, angiotensin-receptor blockers, or calcium channel blockers * Use of immunosuppressive drugs within 30 days prior to study entry or while study is ongoing * Use of corticosteroids within 30 days prior to study entry * Use of steroid medications. More information on this criterion can be found in the protocol. * History of serologic evidence of infection with HIV-1, HBV, or HCV * Receipt of blood products within the past 6 months prior to study entry * Inability to refrain from anal intercourse for the duration of the study * Behavioral, cognitive, or psychiatric disease that, in the opinion of the investigator, would interfere with the study * Pregnant or breastfeeding Step 1 participants: * History of any allergy to food, including peanut * Serum peanut-specific IgE greater than .35 kUa/L at screening * Prick skin test (PST) to peanut more than 3mm in diameter at screening * History of asthma Step 2 participants: * More than mild persistent asthma as defined in the protocol. * Treatment for asthma, including: any hospitalization in the past year for asthma or any emergency room visit in the past 6 months for asthma.