46. What is the nature of the successful anti-cancer Human Papilloma Virus (HPV) vaccine?
    (1) Chemically inactivated virus
    (2) Live attenuated mutant form of HPV
    (3) L1 major capsid proteins self assembled into virus-like particles (VLP)
    (4) mRNA vaccine expressing viral L1 protein mixed with recombinant viral proteins.

The nature of the successful anti-cancer Human Papilloma Virus (HPV) vaccine is:

(3) L1 major capsid proteins self assembled into virus-like particles (VLP)

Explanation

• The currently approved HPV vaccines, such as Gardasil and Cervarix, are based on recombinant L1 capsid proteins from HPV types that self-assemble into virus-like particles (VLPs). These VLPs mimic the structure of the natural virus but do not contain viral DNA and are non-infectious.

• The VLPs induce a strong immune response by presenting the L1 antigen in a native conformation, leading to the production of neutralizing antibodies that provide protection against future HPV infection.

• These vaccines do not use live virus or chemically inactivated whole virions, which makes them very safe and effective.

• Other approaches such as live attenuated HPV, chemically inactivated virus, or mRNA vaccines expressing L1 proteins are not part of the current successful prophylactic HPV vaccine formulations.​