A Study to evaluate if the 3 dose extended schedule (0-6-18 months) for the HPV vaccine Gardasil-9 provide similar immune responses and short term protection against HPV infection compared to the regular 3 dose schedule (0-2-6 months) in high risk women in Vietnam
Primary objective: To determine whether antibody geometric mean titer (GMT) to vaccine type HPV16 and HPV18 at 7 months (m) are non-inferior between female sex workers (FSW) aged 18-26 years who received the standard (0, 2m, 6m) and those received the extended 3-dose (at 0, 6m and 18m) 9vHPV schedule and age-matched non-FSW who received an extended 3-dose (at 0, 6m and 18m) 9vHPV schedule. This extended 3-dose schedule is in line with the recommended schedule by the vaccine manufacturer in Vietnam. Secondary objectives: 1. To compare antibody GMT at 2m, 7m, 18m and 19m between FSW who are HPV DNA+/seropositive with FSW who are HPV DNA-/seronegative at baseline. 2. To compare antibody GMT at 18m and 19m between FSW and non-FSW. 3. To determine cellular immune responses to HPV16 and 18 at baseline, 2m, 7m, 18m and 19m. 4. To measure incidence and 6m/12m/18m persistent HPV infection. Primary hypothesis: HPV antibody GMT to HPV16 and 18 in FSW is non-inferior to those of young women of the same age group (non-FSW) at 7m. Secondary hypothesis: 1. HPV antibody GMT are similar at 2m, 7m, 18m and 19m between FSW who are HPV DNA+/seropositive and HPV DNA-/seronegative at month 0. 2. HPV antibody GMT are similar at 18m and 19m between FSW and non-FSW who received the extended schedule. 3. Cellular immune responses to HPV16 and 18 are similar between FSW and non-FSW at 2m, 7m, 18m and 19m who received the extended schedule. 4. No new vaccine-type HPV infection in FSW and non-FSW in all groups at 6m, 12m, 18m.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
DOUBLE
Enrollment
300
HPV vaccine manufactured by MSD consisted of 9HPV types: 6,11,16,18,31,33, 45, 52,58
Murdoch Children Research Institute
Parkville, Victoria, Australia
Center for Supporting Community Development Initiatives SCDI-Vietnam
Haiphong, Vietnam
Hai Phong Center for Disease Control
Haiphong, Vietnam
Comparison between antibody responses after the 3rd dose ofregular vaccine schedules among FSW and after the 2nd dose of the extended schedule
geometric mean titer (GMT) ratios and 95% confidence intervals (CI) of HPV- specific antibody responses to HPV16 and HPV18 at 7m between FSWs aged 18-26 years who received either the standard (0, 2m, 6m) or extended 3-dose (at 0, 6m and 18m) 3-dose 9vHPV schedule and age-matched non-FSWs who received the extended 3-dose 9vHPV schedule (at 0, 6m and 18m).
Time frame: 7 months from the first doses
Comparison of antibody responses after each doses among FSW according to HPV infection status pre-vaccination
Antibody GMT at 2m, 7m, 18m and 19m between FSW who are HPV DNA+/seropositive with FSW who are HPV DNA-/seronegative at baseline.
Time frame: 19 months after the 1st doses
Comparison of antibody response after 3 doses of extended schedule between FSW and non-FSW
Antibody GMT at 18m and 19m between FSW and non-FSW.
Time frame: 19 month after the first doses
Celular response after each vaccine dose
Proportion of HPV16 and 18-specific B/T cells at baseline, 2m, 7m, 18m and 19m.
Time frame: 19 months after the 1st dose
HPV persistent during 19 month or more among vaccines
4\. Incidence (detection of the specific-type HPV DNA at least once during the follow-up period) and persistent HPV infection (defined as detection of the same HPV type in at least 2 samples not interrupted by negative sample during the follow-up period).
Time frame: at least 19 months after the first dose
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