Development of a microparticulate HPV vaccine for oral delivery

Abstract

Current HPV vaccines are effective in preventing infection with the vaccine types. However, the cost of the vaccine, infrastructure for cold chain and trained personnel, is a major barrier to its introduction in low resource settings. An oral microparticulate vaccine could reduce programmatic costs of HPV vaccine implementation. Our aim was to develop a formulation for oral delivery using HPV16 virus like particles (VLPs), and conduct preclinical tests of immunogenicity.Purified VLPs were incorporated into β‐cyclodextrin microparticles using Buchi B191 spray dryer. 3 doses of the vaccine were administered orally to female BALB/c mice at 2 week intervals. Blood samples were collected prior to inoculation and 1 week after each inoculation for up to 7 weeks. Antibody response was determined using direct HPV16 VLP IgG ELISA.Average size of the microparticles was 3.5± 0.6 μm, with encapsulation efficiency of 60% of VLPs. Electron micrographs confirmed the conformational integrity of the VLPs released from the microparticles. Antibody response was observed in 1/6 mice by week 3 which gradually increased to 4/6 mice by week 7. Current formulation shows promise for development of an effective oral vaccine with modifications to boost the positive response observed in this study.“The findings and conclusions in this report are those of the author(s) and do not necessarily represent the views of the funding agency.”