Monitoring the safety of quadrivalent human papillomavirus vaccine: Findings from the Vaccine Safety Datalink

► We performed a post-licensure safety assessment of HPV4 among 9-26 year old female vaccine recipients between 2006 and 2009. ► Weekly sequential analyses conducted to detect associations between HPV4 exposure and pre-specified outcomes. ► No statistically significant increased risk detected for the outcomes studied. ► A non-significant RR of 1.98 for venous thromboembolism detected, further study needed.