Question

​Describe the process by which HPV infects the stratified squamous epithelium in the cervix of an unvaccinated individual, and explain how this process is disrupted in individuals who have been vaccinated against HPV.

Answer 1

1. HPV (Human Papilloma Virus) is a ds circular DNA virus from the papillomavirus family. This virus can spread through sexual contacts also transfer from mother to baby during pregnancy. The life cycle of HPV follows the differentiation program of the host keratinocytes.

2. HPV limited to infect basal cells of stratified epithelium. It infects epithelial cells through epithelial trauma as soon as the epithelia; cells get exposed.  

3.. HPV mainly infects epithelial cells mostly by entering into basal epithelial through clathrin or caveolin mediated endocytosis. And In some way, the viral genome enters into the nucleus and multiply 10-200 copy no. per cell. Then host keratinocytes begin to divide and differentiate more in the upper layer of epithelial cells.

4. There are 3 vaccines for the HPV Gardasil, Gardasil 9, Cervarix. All 3 prevent the HPV type a6 and 18 which causes 70% of HPV infections.

5. When an individual is given with the vaccine like other immunization body produces antibodies against HPV. This means if in the case in a future individual exposed to this virus antibodies are already there to fight against them. It gets binds to the virus and stops infecting other cells.

6. Vaccine is made up of virus like proteins by surface component of HPV. It it not virulant but it triggers the antgibody production