Dose Study of ACAM2000 Smallpox Vaccine in Previously Vaccinated Adults
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ClinicalTrials.gov Identifier: NCT00053482 |
Recruitment Status :
Completed
First Posted : January 31, 2003
Results First Posted : February 11, 2011
Last Update Posted : August 13, 2018
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Condition or disease | Intervention/treatment | Phase |
---|---|---|
Smallpox | Biological: ACAM2000 Smallpox Vaccine Biological: Vaccinia virus (calf lymph) smallpox vaccine: Dryvax® | Phase 2 |
Specifically, the objectives of this study are to:
- 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.
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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:
- the proportion of subjects at each dose level who develop a major cutaneous reaction
- 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.
- 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 (Clinical Trial) |
Actual Enrollment : | 357 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Primary Purpose: | Prevention |
Official Title: | The Effect of Dose on Safety, Tolerability, and Immunogenicity of ACAM2000 Smallpox Vaccine in Adults With Previous Smallpox Vaccination |
Study Start Date : | January 2003 |
Actual Primary Completion Date : | April 2003 |
Actual Study Completion Date : | October 2003 |

Arm | Intervention/treatment |
---|---|
Experimental: Group 1: ACAM2000
Participants will receive dose 1 of the ACAM2000 smallpox vaccine
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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
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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.
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Biological: Vaccinia virus (calf lymph) smallpox vaccine: Dryvax®
Group 5 dose: 1.0x10-8th PFU/ml
Other Name: Dryvax® |
- 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)
- 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 ]
- 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 ]
- Number of Participants With Treatment-Emergent Rash Events Post-vaccination With ACAM2000 or Dryvax® Smallpox Vaccine [ Time Frame: 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 ]
- 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 ]
- 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 ]
- 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 ]

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 28 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
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.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00053482
United States, Kansas | |
PRA International | |
Lenexa, Kansas, United States, 66219 | |
United States, Missouri | |
Bio-Kinetic Clinical Applications | |
Springfield, Missouri, United States, 65802 | |
United States, Rhode Island | |
Memorial Hospital of Rhode Island Division of Infectious Diseases | |
Pawtucket, Rhode Island, United States, 02860 |
Study Director: | Medical Director | Emergent BioSolutions |
Responsible Party: | Emergent BioSolutions |
ClinicalTrials.gov Identifier: | NCT00053482 |
Other Study ID Numbers: |
H-400-003 |
First Posted: | January 31, 2003 Key Record Dates |
Results First Posted: | February 11, 2011 |
Last Update Posted: | August 13, 2018 |
Last Verified: | August 2018 |
Smallpox vaccines Dryvax® Orthopoxvirus Vaccinia virus ACAM2000 |
Smallpox Poxviridae Infections DNA Virus Infections Virus Diseases |
Infections Vaccines Immunologic Factors Physiological Effects of Drugs |