The cervical cancer vaccine can be given to women who are sexually active or not, between the ages of 9 and 43. Cervical cancer is mainly caused by persistent infection with high-risk HPV virus, and the HPV vaccine is for married women who are sexually active and at high risk for HPV infection. However, the HPV vaccine is only available to those who have not been infected with high-risk HPV virus. For example, there are currently bivalent, quadrivalent and nine-valent HPV vaccines. The bivalent cervical cancer vaccine targets the two highest risk types (16 and 18), while the quadrivalent targets the four types (6, 11, 16 and 18). This means that if you have been infected with one of HPV16 or HPV18, the cost effectiveness of the bivalent cervical cancer vaccine is less than half. If you have been infected with both, then there is no point in getting the bivalent vaccine. So, for women who are already infected with HPV, even if they are not the high-risk type, they should not get the vaccine for now. This is when medication such as interferon is needed to clear the HPV virus first. Only then can the cervical cancer vaccine be administered. However, women who have had sexual intercourse are highly likely to be infected or have been infected with HPV, so it is important to be screened for HPV before vaccination. Cervical exfoliated cells are usually taken clinically to do the test. Therefore, for women who are not sexually active, it is possible to receive the cervical cancer vaccine directly. For women who are sexually active, the vaccine can only be administered if they are not infected with HPV virus.