A dose reduction immunobridging and safety study of two HPV vaccines in Tanzanian girls (DoRIS trial)
The human papillomavirus (HPV) infection is the primary cause of cervical cancer, a major public health concern in sub-Saharan Africa (SSA). In Tanzania, two prophylactic HPV vaccines are licensed to prevent infection with the HPV types associated with the majority of cervical, anal and oral cancers. Scale-up of national HPV vaccination programmes in low-income countries has been slow, partly because of the costs to deliver two or three doses of the HPV vaccine to pre-adolescent and adolescent girls. The aim of this trial is to establish whether a single dose of HPV vaccine produces immune responses that are likely to be effective in preventing cervical cancer in SSA.
To demonstrate non-inferiority of immune responses of 1 dose of HPV vaccine compared with 2 or 3 doses of the same vaccine by evaluating HPV 16/18-specific seropositivity at month 24 and to demonstrate non-inferiority of HPV 16/18 antibody geometric mean titre (GMT) at month 24, when comparing the 1 dose regimen of either vaccine with historical cohorts of women aged 10‒25 years who received 1 dose in whom efficacy has been demonstrated.
This is an unblinded individually-randomised trial involving 930 girls aged 9‒14 years randomised between 2017 and 2018 to one of 6 arms. Arms A, B and C received 3, 2 and 1 dose(s) of the 2-valent vaccine (Cervarix), respectively. Arms D, E and F received 3, 2 and 1 dose(s) of the 9-valent vaccine (Gardasil-9), respectively. Participants in all arms were followed up for 36 months from the first vaccine dose, and those who received one or two vaccine doses are being further followed up for 108 months since the first vaccine dose.
MITU, Tanzania/London School of Hygiene & Tropical Medicine (LSHTM), UK: Saidi Kapiga, Jackton Indangasi, Hilary Whitworth, Caroline Maxwell; LSHTM, UK: Richard Hayes, Philippe Mayaud; Technical University, Berlin, Germany: Wilm Quentin; Karolinska Institute, Sweden: Joakim Dillner; University of York, UK: Charles Lacey; Institut Català d' Oncologia, Spain: Silvia de SanJosé; Frederick National Laboratory for Cancer, MD, USA: Ligia Pinto; University of Glasgow, UK: Kirstin Mitchell