© 2018, Springer International Publishing AG, part of Springer Nature. Background: A patient organization was founded in 2013 due to skepticism about the safety of human papilloma virus (HPV) vaccines. Objective: To evaluate the impact of “priming” patients with information on adverse events following immunization (AEFI) via mainstream media and its impact on reporting by marketing authorization holders (MAHs), healthcare professionals (HCPs), and patients, and to assess the contribution of a pilot patient reporting system for adverse events in Japan to pharmacovigilance. Methods: A summary list of reports of anaphylaxis, vagal reflex, and generalized pain-related AEFI, as presented to the Vaccine Adverse Reactions Review Committee (VARRC) between 2011 and 2016, was analyzed to gain information on MAH and HCP reports. Data on patient AEFI reporting were obtained from a pilot Pharmaceuticals and Medical Devices Agency (PMDA) database designed for this purpose. Data on vaccine shipment volumes were obtained from the VARRC. Results: The leading reporting source transitioned from MAHs (82% of the total AEFI reported in 2010) to HCPs (63% in 2011), and patients (43% in 2015). Sharp peaks were observed for both MAH and HCP reports in 2011. A second peak in pain-related AEFIs reported by HCPs was observed in 2013 when the Ministry of Health, Labour and Welfare suspended the active recommendation of HPV vaccines. Patient reports were continuous and accounted for 21.7% of the total AEFIs reported to the current patient reporting system. Conclusion: In Japan, the characteristics of AEFI reports differed by source for HPV vaccines. MAH and HCP reports identified the major trend in AEFI occurrence during the early post-marketing phase, whereas patient reports in cooperation with HCPs facilitated the detection of weak signals of possible AEFIs throughout the product lifecycle. Patient reporting systems should be encouraged, especially by promoting the communication between patients and local “home” pharmacies in cooperation with patient organizations.