Papillomavirus Research (Jun 2017)

Characterization of a spray-dried candidate HPV L2-VLP vaccine stored for multiple years at room temperature

  • Julianne Peabody,
  • Pavan Muttil,
  • Bryce Chackerian,
  • Ebenezer Tumban

Journal volume & issue
Vol. 3
pp. 116 – 120

Abstract

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HPV infections are associated with human cancers. Although three prophylactic vaccines have been approved to protect against HPV infections, the vaccines require cold-chain storage and may not be suitable for third world countries with less developed refrigeration facilities. We previously developed a bacteriophage L2 virus-like particle (VLP)-based candidate vaccine, which elicited broadly protective antibodies against diverse HPV types. Spray-drying of MS2-16L2 VLPs into a dry powder enhanced the stability of these VLPs. Building on these studies, we assessed the long-term stability and immunogenicity of the spray-dried VLPs. Mice immunized with a single dose of spray-dried MS2-16L2 VLPs, which had been stored for 14 months at room temperature (RT), were partially protected from challenge with a high dose of HPV16, one year after immunization. However, immunization with two doses of MS2-16L2 VLPs stored at RT for 34 months elicited high titer anti-HPV antibodies. More importantly, this group of mice showed significant protection from HPV16, 4 months after immunization. These results suggest that spray-dried MS2-16L2 VLPs retain their effectiveness after long-term storage at RT, and may be suitable in third world countries with less developed refrigeration facilities. Keywords: HPV vaccine, Bacteriophage L2-VLPs, Longevity, Formulation, Spray-drying, Thermostability