I am surprised that this study does not mention which vaccines are being used - as they vary by the number of HPV types they protect against. "Currently there

I am surprised that this study does not mention which vaccines are being used - as they vary by the number of HPV types they protect against. "Currently there are six licensed HPV vaccines: three bivalent (protect against two types of HPV), two quadrivalent (against four), and one nonavalent vaccine (against nine)" - https://en.wikipedia.org/wiki/HPV_vaccine https://en.wikipedia.org/wiki/HPV_vaccine