 - They are women who, if capable of becoming pregnant during the study, have agreed to have a pregnancy test immediately before immunisation, and to use appropriate contraception methods during the whole study period. Appropriate contraception shall include physician-prescribed oral hormonal agents, barrier contraceptives, regular and consistent use of condoms without spermicidal agents, or intrauterine devices only. Progesterone-only contraceptives are not suitable due to the lack of a regular menstrual cycle. 