Dose Study of ACAM2000 Smallpox Vaccine in Previously Vaccinated Adults

March 14, 2024 updated by: Emergent BioSolutions

The Effect of Dose on Safety, Tolerability, and Immunogenicity of ACAM2000 Smallpox Vaccine in Adults With Previous Smallpox Vaccination

The objective of this study is to determine the minimum dose of ACAM2000 needed to produce a cutaneous reaction in at least 90% of a population of healthy adults at least 28 years of age and previously vaccinated against smallpox.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Specifically, the objectives of this study are to:

  1. Compare the safety and tolerability of four dose levels of ACAM2000 and a standard dose of Dryvax® in healthy adults at least 28 years of age and previously vaccinated to smallpox. Safety and tolerability will be determined by examination of the local cutaneous reaction, adverse events, physical examinations, vital signs, structured interviews, and laboratory analysis.

  2. Determine the immunogenicity of four dose levels of ACAM2000 and a standard dose of Dryvax® in healthy adults at least 28 years of age by comparing:

    1. the proportion of subjects at each dose level who develop a major cutaneous reaction
    2. the proportion of subjects in each treatment group who develop neutralizing antibodies, including the fold-increase in antibody titer between Baseline and Day 30 sera; and the geometric mean vaccinia neutralizing antibody titer on Day 30.
  3. Determine the minimum dose of ACAM2000 that is calculated to produce a major cutaneous reaction in at least 90% of a population of healthy adults at least 28 years of age, with a history of smallpox vaccination.

Study Type

Interventional

Enrollment (Actual)

357

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Kansas
      • Lenexa, Kansas, United States, 66219
        • PRA International
    • Missouri
      • Springfield, Missouri, United States, 65802
        • Bio-Kinetic Clinical Applications
    • Rhode Island
      • Pawtucket, Rhode Island, United States, 02860
        • Memorial Hospital of Rhode Island Division of Infectious Diseases

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

28 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion criteria:

  • have a history of previous smallpox vaccination greater than 10 years previous to the date of screening and presence of a vaccination scar.
  • females must not be pregnant, lactating and must agree to use an effective form of birth control for the 30 days following vaccination or unable to bear children.
  • agree to be available for the entire study and agree to comply with all requirements.

exclusion criteria:

  • children 1 year of age or younger in the household or be in close contact
  • smallpox vaccination within ten years
  • known or suspected Human immunodeficient virus (HIV) infection, primary immunodeficiency disorder, leukemia, lymphoma, or current radiation treatment or use of immunosuppressive or anti-neoplastic drugs or have a household member or intimate contact with the conditions listed above.
  • renal disease
  • current or past history of eczema or a household member or direct contact who has eczema.
  • known allergy or past allergic reactions to latex gloves or to antibiotics which include neomycin, streptomycin, chlortetracycline, and polymyxin B
  • known allergy or past allergic reaction to blood products.
  • known allergy to cidofovir or sulfa-containing drugs.
  • history of allergic phenomena following smallpox vaccination in the past, including urticaria, erythema multiforme, or Stevens-Johnson syndrome.
  • transfusion of blood or treatment with any blood product.
  • current or history of drug or alcohol abuse
  • innoculation with any other live vaccine or participating in another drug or vaccine trial within 30 days of enrollment.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Group 1: ACAM2000
Participants will receive dose 1 of the ACAM2000 smallpox vaccine
Biological: ACAM2000 Smallpox Vaccine
Group 1 dose: 1.0x10-8th PFU/ml, Group 2 dose: 2.0x10-7th PFU/ml, Group 3 dose: 1.0x10-7th PFU/ml, Group 4 dose: 5.0x10-6th PFUL/ml
Experimental: Group 2: ACAM2000
Participants will receive dose 2 of the ACAM2000 smallpox vaccine
Biological: ACAM2000 Smallpox Vaccine
Group 1 dose: 1.0x10-8th PFU/ml, Group 2 dose: 2.0x10-7th PFU/ml, Group 3 dose: 1.0x10-7th PFU/ml, Group 4 dose: 5.0x10-6th PFUL/ml
Experimental: Group 3: ACAM2000
Participants will receive dose 3 of the ACAM2000 smallpox vaccine
Biological: ACAM2000 Smallpox Vaccine
Group 1 dose: 1.0x10-8th PFU/ml, Group 2 dose: 2.0x10-7th PFU/ml, Group 3 dose: 1.0x10-7th PFU/ml, Group 4 dose: 5.0x10-6th PFUL/ml
Experimental: Group 4: ACAM2000
Participants will receive dose 4 of the ACAM2000 smallpox vaccine
Biological: ACAM2000 Smallpox Vaccine
Group 1 dose: 1.0x10-8th PFU/ml, Group 2 dose: 2.0x10-7th PFU/ml, Group 3 dose: 1.0x10-7th PFU/ml, Group 4 dose: 5.0x10-6th PFUL/ml
Active Comparator: Group 5: Dryvax®
Participants will receive dose 1 of Dryvax® smallpox vaccine.
Biological: Vaccinia virus (calf lymph) smallpox vaccine: Dryvax®
Group 5 dose: 1.0x10-8th PFU/ml
Other Names:
  • Dryvax®

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The Neutralizing Antibody Response Titers Post-vaccination With ACAM2000 or Dryvax® Smallpox Vaccine
Time Frame: Day 30 post-vaccination
The neutralizing antibody response titers were determined by the Plaque-Reduction Neutralization Test (PRNT50)
Day 30 post-vaccination
Participants With ≥ 4-fold Increase in Plaque-Reduction Neutralization Test (PRNT50) Titers Post-vaccination With ACAM2000 or Dryvax® Smallpox Vaccine.
Time Frame: Day 30 post-vaccination
Day 30 post-vaccination
Number of Participants Reporting Adverse Events of Severe Intensity Post-vaccination With ACAM2000 or Dryvax® Smallpox Vaccine
Time Frame: Days 0 to 30 post-vaccination
Days 0 to 30 post-vaccination

Other Outcome Measures

Outcome Measure
Time Frame
Number of Participants With Treatment-Emergent Rash Events Post-vaccination With ACAM2000 or Dryvax® Smallpox Vaccine
Time Frame: Days 0 to 30 post-vaccination
Days 0 to 30 post-vaccination
Selected Hematology Parameters (Hematocrit, Lymphocyte, and Eosinophil) at Baseline and Day 15 Post-vaccination With ACAM2000 or Dryvax® Smallpox Vaccine
Time Frame: Days 0 (Baseline) and 15 post-vaccination
Days 0 (Baseline) and 15 post-vaccination
Selected Hematology Parameters (Red Bood Cell and Platelets) at Baseline and Day 15 Post-vaccination With ACAM2000 or Dryvax® Smallpox Vaccine
Time Frame: Days 0 (Baseline) and 15 post-vaccination
Days 0 (Baseline) and 15 post-vaccination
Clinical Chemistry Parameters (Creatinine and Glucose) at Baseline and Day 15 Post-vaccination With ACAM2000 or Dryvax® Smallpox Vaccine
Time Frame: Days 0 (Baseline) and 15 post-vaccination
Days 0 (Baseline) and 15 post-vaccination
Clinical Chemistry Parameters (Aspartate Transaminase and Alanine Transaminase) at Baseline and Day 15 Post-vaccination With ACAM2000 or Dryvax® Smallpox Vaccine
Time Frame: Days 0 (Baseline) and 15 post-vaccination
Days 0 (Baseline) and 15 post-vaccination

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Emergent BioSolutions

Investigators

  • Study Director: Medical Director, Emergent BioSolutions

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 2003

Primary Completion (Actual)

April 1, 2003

Study Completion (Actual)

October 1, 2003

Study Registration Dates

First Submitted

January 30, 2003

First Submitted That Met QC Criteria

January 30, 2003

First Posted (Estimated)

January 31, 2003

Study Record Updates

Last Update Posted (Actual)

March 18, 2024

Last Update Submitted That Met QC Criteria

March 14, 2024

Last Verified

March 1, 2024

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • H-400-003

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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