**4. Safety**

Since the main target groups for the HPV vaccines are children and young women that have not initiated sexual activity, safety was the highest priority for the two vaccine producers.

Over the past years many studies have been conducted to ensure safety and tolerability of Cervarix® and Gardasil® [21, 22]. Independent of age, sex or ethnicity, the HPV vaccines are highly safe and well tolerated with very little adverse effects and no significant differences between Gardasil® and Cervarix®. However, in a direct comparison study between the two vaccines, Cervarix® was associated with higher rates of local injection site reactions than Gardasil® [23] (Table 2). This effect might be associated with the differences in adjuvant formulation between the two vaccines.

The most common adverse effects for both vaccines are pain, reddening and swelling at the site of the injection as well as syncope, fatigue, nausea, dizziness and migraine. No severe side effects including auto-immune response abortion or abnormal pregnancy were observed with increased frequency after vaccination with Cervarix® or Gardasil® when compared to the control groups [24-26]


**Table 2.** Percentage of women reporting symptoms at least once within seven days after any vaccine dose (total vaccinated cohort) – Einstein et al., 2009 study [23]
