The quadrivalent HPV vaccine (Gardasil) is described as a recombinant subunit vaccine containing virus-like particles (VLPs). These VLPs are composed of:

• A The E6 and E7 oncoproteins expressed during productive infection
• B Self-assembled L1 major capsid protein expressed in yeast or insect cells ✓
• C The L2 minor capsid protein alone, which bears the broadly cross-neutralising epitope
• D Whole inactivated virions propagated in organotypic epithelial raft cultures

Explanation

HPV cannot be grown conventionally in culture, so the vaccine uses the L1 major capsid protein, expressed recombinantly in Saccharomyces cerevisiae or insect cells, which self-assembles into empty VLPs that present conformational neutralising epitopes without any viral genome. E6 and E7 are oncogenic proteins targeted by therapeutic vaccines in development, not prophylactic ones. L2 is included in newer preparations but the classical VLP platform rests on L1.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.