Head-to-head immunogenicity comparison of one-dose Cecolin and Gardasil in Chinese girls aged 9-14 years: A randomized and open-label clinical trial.

BACKGROUND

The World Health Organization (WHO) urges global administration of at least one dose of the HPV vaccine, particularly for girls aged 9-14, to work towards the elimination of cervical cancer. However, data on the efficacy of a single dose of Cecolin®, a bivalent HPV vaccine, remain quite limited. Therefore, it is crucial to design studies investigating the protective effects of a single dose of Cecolin® in Chinese girls.

METHODS

The randomized clinical trial began on February 23, 2023 (NCT06345885). 198 Chinese girls aged 9-14 received a single dose of Cecolin® or Gardasil®. Seroconversion rates and geometric mean titers (GMTs) for HPV16 and HPV18 were assessed at one and two months post-vaccination. Non-inferiority was declared if the lower limit of the 95 % confidence interval (CI) exceeded -5 %. Safety of vaccine was evaluated in all vaccinated participants.

RESULTS

At one month post-vaccination, both the Cecolin® and Gardasil® groups achieved 100 % seroconversion for HPV16 antibodies. The seroconversion rates for HPV18 were 97.9 % (95 % CI: 92.5 %, 99.7 %) in the Cecolin® group and 95.6 % (95 % CI: 89.1 %, 98.8 %) in the Gardasil® group. The GMTs in the Cecolin® group were significantly higher than those in the Gardasil® group for both HPV types, with GMT ratios of 1.5 (1.1, 2.1) for HPV16 and 2.84 (2.0, 4.1) for HPV18. The seroconversion rates and GMT ratios one month after a single dose of Cecolin® were non-inferior to those of Gardasil®, with results remaining consistent at two months. The incidence of adverse events was similar between the two groups throughout the study, with no statistically significant differences.

CONCLUSION

The immunogenicity and safety of a single dose of Cecolin® in Chinese girls aged 9-14 years were comparable to those of Gardasil. These findings support the use of single-dose Cecolin® to enhance HPV vaccination coverage for cervical cancer prevention.