The HPV vaccine is different from most other vaccines because the viral components in the vaccine are not derived from the actual virus itself. The ingredients are made in the laboratory by bioengineering, so the vaccine is completely devoid of whole viral particles. Since the vaccine does not contain any viral parts, it is impossible for the vaccine to cause HPV infection.

The HPV vaccine does not contain thimerosal, and this mercury-based preservative is never used during the vaccine manufacturing process.