Post-approval Safety Monitoring of Quadrivalent and Bivalent Human Papillomavirus Vaccines Based on Real-world Data from the Korea Adverse Events Reporting System (KAERS)

BACKGROUND AND OBJECTIVES

The vaccine adjuvant, AS04, present in bivalent human papilloma virus (bHPV) vaccines, induces greater local immune responses than the aluminum adjuvant in quadrivalent HPV (qHPV) vaccines. These distinctions might also result in disparities in immunogenicity and responsiveness, possibly contributing to differences in adverse events (AEs) between these vaccines. Here we comparatively analyzed AEs between qHPV and bHPV vaccines based on 10-year real-world AE data.

METHODS

We evaluated the Korea Adverse Events Reporting System (KAERS), a nationwide drug database including vaccines from January 2007 to December 2016, analyzing AEs reported for qHPV and bHPV vaccines. Vaccine-AE pairs were generated, and the characteristics of all reported AEs were analyzed. Signals were derived using the disproportionality method of signal detection algorithms (reporting odds ratios and information component).

RESULTS

Of the total 2566 HPV vaccine-associated AE reports, 2686 and 1994 were vaccine-AE pairs for qHPV and bHPV, respectively. Application site disorders were the most frequent AEs for both vaccines but were more frequently reported with the bHPV vaccine. The characteristics of non-application site AEs between the two vaccines were generally similar, but systemic AEs such as fever and fatigue were more common with the bHPV vaccine. Tremor, rash, eye pain, myopathy and circulatory failure were identified as signals in both qHPV and bHPV vaccines.

CONCLUSIONS

Both application site disorders and systemic AEs were somewhat more frequent with the bHPV vaccine than with the qHPV vaccine. This might be caused by an immune response induced by adjuvants contained within the vaccines.

Factors Influencing HPV Vaccination Intention in Mothers with Elementary School Daughters

PURPOSE

The purpose of this study was to identify the impacts of human papillomavirus (HPV) vaccination-related health belief, attitudes toward HPV vaccination, and subjective norms on HPV vaccination intent targeting mothers of elementary school daughters.

METHODS

The study use a correlative survey design. The subjects of the study were 121 mothers of elementary school daughters located in metropolitan city B. All subjects agreed to participate in the study. The data were collected from September 1 to October 18, 2018, and were analyzed using descriptive statistics, Independent t-test, ANOVA with a post hoc Scheffé test, Pearson's correlation coefficients, and stepwise multiple regression.

RESULTS

Attitude toward HPV vaccination, subjective norms, vaccination plans for their children, and mother's vaccination status were significant factors influencing HPV vaccination intention. These factors accounted for 72% of the HPV vaccination intention. CONCLUSIONS: This study showed that factors affecting the intention of mothers of elementary school daughters to vaccinate against HPV were HPV vaccination attitudes, subjective norms, vaccination plans for their children, and mother's vaccination status. The biggest influencing factor was HPV vaccination attitudes. Therefore, in order to encourage mothers of elementary school daughters to vaccinate against HPVs, national-level policies should be implemented to create a social atmosphere of positive attitudes toward HPV vaccinations that also emphasizes how easy it is to get vaccinated against HPV. Based on this, mothers of elementary school daughters should be encouraged to have them vaccinated against HPV, thus contributing to improving the HPV vaccination rates of elementary school girls.