There is no authoritative information on whether the nine-valent vaccine is effective if only one injection is given. It is generally believed that the effect is not significant and does not play a preventive role, and that the normal three injections will have some effect. The nine-valent vaccine is mainly used to prevent many types of human papillomavirus infections. At present, there is no relevant authoritative information on whether the nine-valent vaccine is effective in only one shot, in general, it is considered that the nine-valent vaccine is not very effective in only one shot, and may not be effective, and can not play a role in preventing viral infections, and has no clinical significance. Under normal circumstances, the nine-valent vaccine needs to be given three doses throughout the year, and in most cases it can be given in about 6 months, with an interval of at least 1 month between the first and second doses, and an interval of at least 3 months between the second and third doses. The appropriate age for the nine-valent vaccine is 16 to 26 years old, and it can prevent more than 90% of cervical cancers and genital warts. In summary, if you are interested in receiving the nine-valent vaccine, you need to take the whole course of the vaccination, and it is not recommended to interrupt in the middle of the course, so as not to affect the immunization effect.