STEP trial and HIV-1 vaccines inducing T-cell responses

Abstract

Recombinant, nonreplicating, human adenovirus serotype 5-vectored vaccine, known as MRKAd5, expressing three HIV-1 clade B-derived internal proteins when used in a homologous immunization regimen, did not decrease HIV-1 infection rate nor postinfection virus load in the first Phase IIb proof-of-concept trial. However, the vaccine did not reach the limits of vaccine T-cell induction and its design can be improved both from the point of the HIV-1-derived immunogens and their delivery. Therefore, failure of the first experimental HIV-1 vaccine focusing on induction of T-cell responses cannot be a reason for dismissal of the whole T-cell vaccine concept, nor for losing a positive attitude toward systematic HIV-1 vaccine development.

Keywords::

• clinical trial
• HIV vaccine
• Phase IIb proof-of-concept trial
• T cell

Acknowledgements

The author would like to thank Lucy Dorrell and Andrew McMichael for their comments on the manuscript.

Financial & competing interests disclosure

T Hanke has received grants from EDCTP/BMGF, the Japanese Health Science Foundation and MRC UK. T Hanke also holds patents for methods and reagents for vaccination, which generate a CD8 T-cell immune response; improvements in, or relating to, immune response to HIV; RENTA: an HIV immunogen and uses thereof; and HIVCON: an HIV immunogen and uses thereof. The author has no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.