Rationale and design of a long term follow-up study of women who did and did not receive HPV 16/18 vaccination in Guanacaste, Costa Rica.

Gonzalez P, Hildesheim A, Herrero R, Katki H, Wacholder S, Porras C, Safaeian M, Jimenez S, Darragh TM, Cortes B, Befano B, Schiffman M, Carvajal L, Palefsky J, Schiller J, Ocampo R, Schussler J, Lowy D, Guillen D, Stoler MH, Quint W, Morales J, Avila C, Rodriguez AC, Kreimer AR