Clinical Trials Logo

Clinical Trial Summary

The purpose of this study is to determine the safety and effect of diluting smallpox vaccine, making a larger number of doses in case smallpox is released into the environment. A total of up to 927 healthy adults between the ages of 32 and 70 years who were already vaccinated against smallpox (but not since 1989) will volunteer for this study for up to 34 weeks and receive different strengths of vaccine. Some subjects may participate for longer if they choose to be revaccinated because the first vaccination does not take. The vaccine will be given by making small cuts in the skin and putting the vaccine into these cuts. After the screening visit, volunteers will be followed through study visits and follow up phone calls. Blood will be collected during some study visits to look at the immune system (body system that fights infection) response.


Clinical Trial Description

The purposes of this multi-center, double blind randomized dose response study are: to evaluate the safety of undiluted Dryvax and Dryvax diluted at 1:5 and 1:10 in adults between the ages of 32 and 70 years who were previously vaccinated but not since 1989 and to define, with very high precision (+/-3%), the proportion of individuals who respond with a "take" 6 to 11 days after vaccination with undiluted Dryvax vaccine and Dryvax diluted at 1:5. A "take" is defined as the formation of a lesion at the site of vaccination that is consistent with the description of a successful vaccination described in the IB Secondary study objectives include defining with good precision (+/- 10%), the proportion of individuals who respond with a "take" 6 to 11 days after vaccination with a 1:10 dilution of Dryvax vaccine and exploring correlations between "takes"/ no-"take" and immune responses in all vaccine groups (antibody responses in all volunteers; and assays of cell-mediated immunity in a convenience sample consisting of 15 volunteers enrolled at each site (total N = 105) randomly distributed across the vaccine groups). Immunogenicity assays will include neutralizing antibody to vaccinia, vaccinia binding antibody, ELISPOT for gamma interferon [Assays of cell-mediated immunity will be performed only on a convenience sample consisting of 15 volunteers enrolled at each site (total N = 105)] and intracellular cytokine production. Primary safety endpoints include safety data regarding the three doses of vaccine in previously vaccinated subjects as assessed by adverse events reported by the subjects and/or investigators and changes observed during the scheduled clinic visits. Specific attention will be paid to the following: local reactogenicity at the site of injection: pain, tenderness, erythema, induration, regional lymphadenopathy, limitation of limb movement; systemic symptoms: fever, myalgia, fatigue, and headache; anaphylaxis, and hypersensitivity reactions; other reactions: dermatologic, neurologic, gastrointestinal (nausea/vomiting, diarrhea). The primary efficacy endpoint for this trial will be the proportion of vaccinees demonstrating a "take" 6 to 11 days after the first vaccination at each of the dose levels (undiluted and 1:5 and 1:10). Secondary endpoints are: immune responses as assessed by vaccinia neutralizing antibody measured on all subjects and binding antibody to vaccinia on all subjects and the size of the lesions observed in all subjects compared across the dilution groups. Tertiary endpoints of 15 volunteers at each site randomly distributed across the vaccine groups are cellular immune responses as assessed by: ELISPOT for gamma interferon in response to vaccinia antigens and intracellular cytokine production. ;


Study Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Investigator), Primary Purpose: Prevention


Related Conditions & MeSH terms


NCT number NCT00050505
Study type Interventional
Source National Institute of Allergy and Infectious Diseases (NIAID)
Contact
Status Completed
Phase Phase 2
Start date October 2002
Completion date December 2003

See also
  Status Clinical Trial Phase
Completed NCT05976100 - Study of the Safety, Tolerability, Pharmacokinetics of NIOCH-14 in Volunteers Aged 18-50 Years Phase 1
Completed NCT01540929 - Post-licensure Department of Defense (DOD) Screening Accuracy Study in Military Personnel
Completed NCT00258947 - Evaluation of Take and Safety of a Smallpox Vaccine in Healthy Young Adults Phase 2
Completed NCT00189969 - Take Rate, Immunogenicity and Safety of Elstree-BN Smallpox Vaccine in Healthy Vaccinia-Naive Subjects Phase 1
Terminated NCT00053508 - Dose Safety, Tolerability, and Immunogenicity of a New Smallpox Vaccine in Adults Without Previous Smallpox Vaccination Phase 2
Completed NCT01317238 - Safety and Efficacy of CJ Smallpox Vaccine in Previously Vaccinated Healthy Volunteers Phase 3
Completed NCT01056770 - Safety and Efficacy of CJ Smallpox Vaccine in Healthy Volunteers Phase 3
Completed NCT00998543 - A Long-Term Study of Healthy Adults Vaccinated With One Dose of Smallpox Vaccine (LISTER Strain) Phase 2
Terminated NCT00282581 - Safety Study of MVA Smallpox Vaccine in HIV-positive Subjects Who Are Vaccinia Naive Phase 1
Withdrawn NCT00389103 - Safety Study of MVA Smallpox Vaccine in Subjects With a History of Atopic Dermatitis (AD) Phase 1
Completed NCT00133575 - ACAM 3000 MVA at Harvard Medical School Phase 1/Phase 2
Active, not recruiting NCT00103584 - Safety and Immunogenicity Study of LC16m8, a Modified Smallpox Vaccine, in Healthy, Previously Unvaccinated Volunteers Phase 1/Phase 2
Completed NCT05846243 - Study on Immunogenicity, Reactogenicity and Safety of the VACΔ6 Vaccine in Volunteers Aged 18-60 Years Phase 2/Phase 3
Completed NCT05935917 - Study Evaluating the Bioequivalence of Brincidofovir Form H and Form II Tablets in Healthy Adults Phase 1
Completed NCT00082446 - Combination Study With MVA BN and Dryvax Phase 1
Completed NCT00038987 - Vaccinia Virus Vaccine (APSV) in Vaccinia- Naive Subjects: PILOT Phase 1/Phase 2
Completed NCT05762523 - Safety and Tolerability Study of the VAC∆6 Vaccine in Volunteers Aged 18-40 Years Phase 1
Completed NCT04971109 - Safety, Tolerability and Pharmacokinetics of TPOXX When Administered Orally for 28 Day Phase 3
Completed NCT00646152 - Poly-ICLC to Prevent Respiratory Viral Infections A Safety Study Phase 1
Completed NCT01668537 - A Phase II Trial to Compare a Liquid-frozen and a Freeze-dried Formulation of IMVAMUNE (MVA-BN®) Smallpox Vaccine in Vaccinia-naïve Healthy Subjects Phase 2