Preliminary Assessment of the Efficacy of a T-Cell–Based Influenza Vaccine, MVA-NP+M1, in Humans Academic Article uri icon

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abstract

  • BACKGROUND: The novel influenza vaccine MVA-NP+M1 is designed to boost cross-reactive T-cell responses to internal antigens of the influenza A virus that are conserved across all subtypes, providing protection against both influenza disease and virus shedding against all influenza A viruses. Following a phase 1 clinical study that demonstrated vaccine safety and immunogenicity, a phase 2a vaccination and influenza challenge study has been conducted in healthy adult volunteers. METHODS: Volunteers with no measurable serum antibodies to influenza A/Wisconsin/67/2005 received either a single vaccination with MVA-NP+M1 or no vaccination. T-cell responses to the vaccine antigens were measured at enrollment and again prior to virus challenge. All volunteers underwent intranasal administration of influenza A/Wisconsin/67/2005 while in a quarantine unit and were monitored for symptoms of influenza disease and virus shedding. RESULTS: Volunteers had a significantly increased T-cell response to the vaccine antigens following a single dose of the vaccine, with an increase in cytolytic effector molecules. Intranasal influenza challenge was undertaken without safety issues. Two of 11 vaccinees and 5 of 11 control subjects developed laboratory-confirmed influenza (symptoms plus virus shedding). Symptoms of influenza were less pronounced in the vaccinees and there was a significant reduction in the number of days of virus shedding in those vaccinees who developed influenza (mean, 1.09 days in controls, 0.45 days in vaccinees, P = .036). CONCLUSIONS: This study provides the first demonstration of clinical efficacy of a T-cell-based influenza vaccine and indicates that further clinical development should be undertaken. CLINICAL TRIALS REGISTRATION: NCT00993083.

authors

  • Lillie, Patrick J
  • Berthoud, Tamara K
  • Powell, Timothy J
  • Lambe, Teresa
  • Mullarkey, Caitlin
  • Spencer, Alexandra J
  • Hamill, Matthew
  • Peng, Yanchun
  • Blais, Marie-Eve
  • Duncan, Christopher JA
  • Sheehy, Susanne H
  • Havelock, Tom
  • Faust, Saul N
  • Williams, Rob Lambkin
  • Gilbert, Anthony
  • Oxford, John
  • Dong, Tao
  • Hill, Adrian VS
  • Gilbert, Sarah C

publication date

  • July 1, 2012

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