17D yellow fever vaccine elicits comparable long-term immune responses in healthy individuals and immune-compromised patients

J Infect. 2016 Jun;72(6):713-722. doi: 10.1016/j.jinf.2016.02.017. Epub 2016 Mar 24.

Abstract

Background: The 17D live attenuated yellow fever (YF) vaccine is contra-indicated in immune-compromised individuals and may elicit a suboptimal immunologic response. The aim of this study is to assess whether long-term immune responses against the YF vaccine are impaired in immune-compromised patients.

Materials and methods: Fifteen patients using different immunosuppressive drugs and 30 healthy individuals vaccinated 0-22 years ago were included. The serological response was measured using the plaque reduction neutralization test (PRNT). CD8(+) and CD4(+) T-cell responses were measured following proliferation and re-stimulation with YFV peptide pools. Phenotypic characteristics and cytokine responses of CD8(+) T-cells were determined using class I tetramers.

Results: The geometric mean titre of neutralizing antibodies was not different between the groups (p = 0.77). The presence of YFV-specific CD4(+) and CD8(+) T-cell did not differ between patients and healthy individuals (15/15, 100.0% vs. 29/30, 96.7%, p = 0.475). Time since vaccination correlated negatively with the number of YFV-specific CD8(+) T-cells (r = -0.66, p = 0.0045). Percentages of early-differentiated memory cells increased (r = 0.67, p = 0.017) over time.

Conclusion: These results imply that YF vaccination is effective despite certain immunosuppressive drug regimens. An early-differentiated memory-like phenotype persisted, which is associated with effective expansion upon re-encounter with antigen, suggesting a potent memory T-cell pool remains.

Keywords: 17D yellow fever; Immune-compromised; Vaccination.

MeSH terms

  • Adult
  • Aged
  • Antibodies, Neutralizing / blood
  • Antibodies, Viral / blood*
  • CD8-Positive T-Lymphocytes / immunology*
  • Cytokines / biosynthesis
  • Cytokines / immunology*
  • Female
  • Healthy Volunteers
  • Humans
  • Immunocompromised Host*
  • Male
  • Middle Aged
  • Neutralization Tests
  • Time Factors
  • Vaccination
  • Yellow Fever Vaccine / administration & dosage
  • Yellow Fever Vaccine / immunology*
  • Yellow fever virus / immunology*
  • Young Adult

Substances

  • Antibodies, Neutralizing
  • Antibodies, Viral
  • Cytokines
  • Yellow Fever Vaccine