Safety and immunogenicity of a bivalent cytomegalovirus DNA vaccine in healthy adult subjects

J Infect Dis. 2008 Jun 15;197(12):1634-42. doi: 10.1086/588385.


Background: VCL-CB01, a candidate cytomegalovirus (CMV) DNA vaccine that contains plasmids encoding CMV phosphoprotein 65 (pp65) and glycoprotein B (gB) to induce cellular and humoral immune responses and that is formulated with poloxamer CRL1005 and benzalkonium chloride to enhance immune responses, was evaluated in a phase 1 clinical trial.

Methods: VCL-CB01 was evaluated in 44 healthy adult subjects (22 CMV seronegative and 22 CMV seropositive) 18-43 years old. Thirty-two subjects received 1- or 5-mg doses of vaccine on a 0-, 2-, and 8-week schedule, and 12 subjects received 5-mg doses of vaccine on a 0-, 3-, 7-, and 28-day schedule.

Results: Overall, the vaccine was well tolerated, with no serious adverse events. Local reactions included mild to moderate injection site pain and tenderness, induration, and erythema. Systemic reactions included mild to moderate malaise and myalgia. All reactions resolved without sequelae. Through week 16 of the study, immunogenicity, as measured by enzyme-linked immunosorbant assay and/or ex vivo interferon (IFN)-gamma enzyme-linked immunospot assay, was documented in 45.5% of CMV-seronegative subjects and in 25.0% of CMV-seropositive subjects who received the full vaccine series, and 68.1% of CMV-seronegative subjects had memory IFN-gamma T cell responses at week 32.

Conclusion: The safety and immunogenicity data from this trial support further evaluation of VCL-CB01.

Publication types

  • Clinical Trial, Phase I
  • Controlled Clinical Trial
  • Multicenter Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Adult
  • Antibodies, Viral / blood*
  • Cytomegalovirus / immunology
  • Cytomegalovirus Vaccines / adverse effects*
  • Cytomegalovirus Vaccines / immunology*
  • Dose-Response Relationship, Immunologic
  • Female
  • Humans
  • Immunologic Memory
  • Kinetics
  • Male
  • T-Lymphocytes / physiology
  • Time Factors
  • Vaccines, DNA / adverse effects*
  • Vaccines, DNA / immunology*


  • Antibodies, Viral
  • Cytomegalovirus Vaccines
  • Vaccines, DNA