Immunogenicity and safety of human papillomavirus (HPV) vaccination in Asian populations from six countries: a meta-analysis.

Cervical cancer is a serious public-health problem in Asian countries. Since human papillomavirus (HPV) infection is the main risk factor for cervical cancer, HPV vaccination is considered a promising strategy to prevent cervical cancer. However, comprehensive immunogenicity and safety information for Asian populations is lacking. We searched four electronic databases including PubMed, EMBASE, Cochrane Library, and clinicaltrials.gov. We reviewed selected manuscripts and extracted the pooled relative risk (RR) from immunogenicity and safety information on HPV vaccination among women in Asian countries. We identified two quadrivalent-vaccine studies and eight bivalent-vaccine studies conducted in Asian countries. Analysis across these studies suggested that the HPV vaccines significantly enhanced HPV16- and HPV18-specific antibody among both uninfected (RR 85.69; 95% confidence interval (CI) 31.51-233.04 and 62.77; 95% CI 37.4-105.51) and infected individuals (RR 8.60; 95% CI 6.95-10.64 and RR 8.13; 95% CI 5.96-11.11). Furthermore, HPV vaccination among Asian populations has a favorable safety profile, with only slightly higher risks of local (RR: 1.89; 95% CI 1.65-2.17) and systemic (RR: 1.33; 95% CI 1.18-1.50) adverse events in vaccinated individuals compared with controls. For Asian populations, HPV vaccines enhance the level of HPV16- and HPV18-specific antibodies for both uninfected and infected individuals. Also, the risk of adverse events related to vaccination are acceptable. More data are needed to establish vaccine efficacy with regard to prevention of HPV infection and further outcomes including cervical intraepithelial neoplasia (CIN) and cervical cancer.