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

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
357

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

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

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
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

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
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

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Emergent BioSolutions

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • 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

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2003

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 1, 2003

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
October 1, 2003

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 30, 2003

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 30, 2003

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 31, 2003

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 18, 2024

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 14, 2024

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2024

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant 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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