Immunogenicity and safety of two human papillomavirus vaccines for cervical cancer among Asian female populations : a systematic review

Abstract

Cervical cancer is one of the common cancers among women and poses a great burden to the public health. Currently there are two human papillomavirus vaccines, CervarixTM and Gardasil®, against HPV type 16/18 and type 6/11/16/18 cervical cancer available in the market. Most clinical trials about immunogenicity and safety of the two vaccines were conducted among Caucasian females, rather than on Asian female populations. This systematic review aims to summarize and evaluate immunogenicity and safety of the two vaccines conducted mainly at the setting of randomized control trials on Asian female populations. This investigation would enhance understanding about whether ethnic difference impacts antibody responses, what were the severe adverse events in Asian populations, and whether the vaccines demonstrate satisfactory immunogenicity.

Eleven relevant studies were identified from Pubmed and Medline with totally 4026 subjects involved. The quality and validity of these studies was critically appraised in terms of randomization, allocation ratio, blinding, analytical methods and other potential limitations.

The two vaccines demonstrated high geometric mean antibody titer levels among Asian females. Injection-site pain was the mostly complained solicited local symptom, followed by redness and swelling. Few severe solicited local symptoms were reported. The unsolicited symptoms were not as common as solicited symptoms and quite a few of them were not related to the vaccination. One severe adverse event was confirmed in Japan’s study – a spontaneous abortion had taken place 15 days after vaccination.

China lacks of systematic cancer registries, therefore it is difficult to estimate the disease burden. China’s Gross Domestic Product only reached $5445 per capita in 2011. HPV vaccination would not be cost-effective in the countries which had Gross Domestic Product lower than $8505 per capita, therefore piloting the HPV vaccination in major economic powerhouses like Shanghai and Beijing would be more realistic.

To sum up, this systematic review demonstrated satisfactory immunogenicity on Asian females. The safety data were acceptable to some extent except one spontaneous abortion occurred in Japan’s study.