Because the HPV does not mix with the blood, the body does not develop a strong systemic immune response. Therefore, people who have not been vaccinated may get infected with the virus again and again after each transmission. Moreover, when the virus settles in the body, it infects the neighboring regions repeatedly. Tear off the warts, cutting them with a razor, or removing them using wax may causes the virus to re-infect the nearby skin. Since there are many types of the virus, re-infection with different types is possible as long as the person continues to encounter the virus. Re-infections (in fact, the continuation of the same infection) can be observed in 10% of patients due to their weak immune systems that allow for the virus to survive in their skin and cervix cells.