Cervical cancer is a significant public health problem in Africa and a leading cause of cancer deaths in women. According to the WHO, Africa has the highest cervical cancer disease incidence and associated mortality in the world accounting for 19% of all global cases of cervical cancer and 23% of all cervical cancer related deaths. The high-risk Human Papillomavirus (HPV) Types16 and 18 are responsible for 70% of all global cervical cancers with a high prevalence of 22% in sub-Saharan Africa compared to a prevalence of 12%globally. The bivalent Cecolin HPV vaccine, manufactured by Innovax of China, has demonstrated \>95% efficacy against HPV16/18 infections in women aged 18 to 26 years and some protection against HPV 31, 33 and 45. The hypothesis of this trial is that infants/toddlers vaccinated with the bivalent Cecolin will show similar safety, tolerability, and immunogenicity as compared to that observed in older age groups, 15 to 20year old, where efficacy has been established.
This trial is a proof-of-concept study to descriptively compare the safety, tolerability, and immunogenicity of HPV vaccination in a pediatric population. The aim is to demonstrate safety and tolerability, and that short-term immune responses in infants and toddlers are comparable to the responses in older girls and women between 15-20 years, an age group in whom efficacy has been shown. If the vaccines are shown to be safe, well tolerated, and sufficiently immunogenic in this pilot study, this would provide evidence to support larger statistically robust studies to test the safety, immunogenicity, longevity of immune response, and acceptability of including HPV vaccines in the routine EPI.
A total of one hundred and fifteen (N=115) eligible participants will be enrolled in the study with an age de-escalation approach for the pediatric cohort. First, the safety cohort of 15 children between the age of 2-5 years will be randomized in a 3:2 ratio to receive HPV (n=9) and placebo (n=6). To progress enrolment of toddlers aged 15 months, the DSMB will review safety data of the preceding safety cohort (2-5 years old) collected in the first week (until D7 visit) of follow-up according to pre-specified halting criteria. If halting criteria are not met, a further 15 toddlers (15 months) will be recruited similarly in a 3:2 ratio to receive HPV (n=9) and placebo (n=6). After the recruitment of the first 15 of 35 toddlers, there will be a second safety review by the DSMB. If halting criteria are not met, the remaining 20 participants of the 15-month-old cohort will continue recruitment. Following confirmation by the DSMB, 15 infants (9 months old) will be recruited similarly in a 3:2 ratio to receive HPV (n=9) and placebo (n=6). After the recruitment of the first 15 of 35 infants, there will be another safety review by the DSMB. If halting criteria are not met, the remaining 20 participants of the 9-month-old cohort will continue recruitment. The safety cohort and the toddlers will receive either a single dose of the HPV vaccine or placebo while the 9-month-old will either receive two doses of the HPV vaccine 6 months apart or the placebo. Adolescent girls and young women aged between 15 and 20 year olds will be recruited in open label study in parallel.
