人乳头瘤病毒及其疫苗研究进展

Human papillomavirus (HPV) is the DNA virus that infects skin or mucosal cells. There are more than 100 known HPV genotypes, at least 13 of which cause cancer of the cervix and are associated with other anogenital cancers and cancers of the head and neck; they are called “high-risk” genotypes. The two most common genotypes (genotypes 16 and 18) cause appro- ximately 70% of all cervical cancers. HPV (especially genotypes 6 and 11) also causes genital warts, a common benign condition of the external genitalia that causes significant morbidity. HPV is highly transmissible, with peak incidence of infection soon after the beginning of sexual activity. Most people acquire the infection at some time in their life. Factors contributing to development of cervical cancer after HPV infection include immune suppression, multiparity, early age at first delivery, cigarette smoking, long-term use of hormonal contraceptives, and co-infection with Chlamydia trachomatis or Herpes simplex virus. HPV vaccines are prepared from virus-like particles (VLPs), produced by recombinant technology. They do not contain any live biological product or DNA, so are non-infectious. A quadrivalent vaccine produced by Merck Company, containing VLPs related to HPV genotypes 6, 11, 16 and 18, was firstly licensed in 2006, and a bivalent vaccine produced by GSK company, containing VLPs related to HPV genotypes 16 and 18, was licensed afterwards. The vaccines are designed to prevent infection and disease due to their respective genotypes, and are not designed to treat persons who have already been infected with them. HPV vaccines induce high levels of serum antibodies in virtually all vaccinated individuals and are generally well tolerated. Adverse events at the injection site occur more often in vaccine recipients than controls, but the incidence of serious adverse events (SAEs) was not significantly higher among vaccine recipients in any of the trials.