An Advisory Committee Statement (ACS) National Advisory Committee on Immunization (NACI)

In a 3-dose schedule, the minimum interval between the first and second doses of vaccine is 4 weeks, the minimum interval between the second and third doses of vaccine is 12 weeks and the minimum interval between the first and last doses in either a 2-dose or 3-dose schedule is 24 weeks. [...] The review included studies of the HPV2 vaccine with follow up of 9.4 years, and 8 years for the HPV4 vaccine, and found that the vaccine continues to be immunogenic and well tolerated up to 9 years following vaccination, and that all randomized controlled clinical trials of the two vaccines provide evidence of an excellent safety profile. [...] METHODS HPV9 vaccine NACI reviewed the key questions for the literature review on HPV9 vaccine as proposed by the HPV Working Group, including: the burden of illness of the disease to be prevented and the target population(s), safety, immunogenicity, efficacy, effectiveness of the vaccine(s), vaccine schedules, and other aspects of the overall immunization strategy. [...] Minimum intervals between HPV vaccine doses in a 3- dose immunization schedule NACI reviewed the key questions for the literature review on acceptable minimum intervals between HPV vaccine doses as proposed by the HPV Working Group, including the specific question of the acceptable minimum interval between the first and last dose of HPV vaccine in a 3-dose schedule. [...] Successful demonstration of the primary immunogenicity hypothesis of non-inferiority required the lower boundary of the two-sided 95% confidence interval of the ratio of the geometric mean titre (GMT) (HPV9:HPV4) to be greater than 0.67 for each of the anti-HPV types 6, 11, 16, and 18.