I think that besides having a vaccine for HPV types 16 and 18 there should also be vaccines made for HPV31 and HPV 45 because those account for up to 80% of cervical cancers. The other strains 33, 35, 39, 51, 52, 56, 58 and 59 together only make up 20% of the causes for the cancers but there are more of them, so it would not be cost efficient to make vaccines for each one of those strains. On top of that they are also only classified as possibly carcinogenic so we are not completely sure if they are even associated with cervical cancers and it would be unwise to spend money creating vaccines for all those times. I think it is more important to focus on the known most common cancer causing strains of 31 and 45. I think these vaccines should be administered around the age of puberty which is when most kids will realize and explore their sexuality with others, and especially before someone thinks that they will be sexually active to ensure most safety. Since there is a chance that they could be infected through viral particles as well, it may be wise to get it before deciding to even kiss a partner, especially if that partner has had multiple sexual partners before. Not only will this help ensure safe sexual exploration and avoidance of warts, it could also prevent cancers stemming from HPV as well.