Passive surveillance systems are able to identify safety signals, but are subject to known limitations, due to underreporting, delayed reporting and a lack of denominator data. Active surveillance in a defined PR-171 mw cohort of vaccines can complement passive surveillance by overcoming problems of delayed and underreporting and enabling calculation of adverse event rates. Recent studies internationally have emphasised the importance

of active surveillance to detect important signals early so that appropriate investigations can be launched and necessary actions taken [8] and [9]. Internationally the usefulness of Patient Reported Outcomes (PROs) utilising available internet tools has been increasingly recognised. There is evidence that in relation to adverse events PROs can identify real-world signals earlier and in higher volume, accurately characterise the signals, allow a focus on specific events

or populations of interest, and permit ongoing efficient safety monitoring [10]. The finding that there was a significantly higher rate of reactions in participants who received IIV in the previous year deserves further investigation as it has not been a consistent finding in previous studies [3]. The initial practice visit by Vaxtracker staff of this pilot phase could be replaced by a brief diagrammatic user guide or online web PF01367338 demonstration to further improve efficiency and reduce the cost of the roll out phase. We estimate that once established the ongoing human resources to operate the system are not great as survey results provide sufficient information for assessment and very few respondents require subsequent telephone clarification of clinical details or support. After the Vaxtracker survey was completed by respondents, case review and data analysis for signal detection quickly take place. The automatic management of survey dispatch and return of completed surveys and email alerts has allowed for the efficient and

prompt review of AEFIs and rapid data analysis and rate calculation. It is essential to reassure the community of vaccine safety and to prompt Phosphoprotein phosphatase early investigation should severe reactions occur or if there is an unexpected increase in the frequency of clinical events [11]. The Vaxtracker active surveillance system achieved encouraging completion rates. These were found to be higher where parents received both mobile phone and email reminders. Feedback and a certificate of appreciation were provided to all General Practice clinics that enrolled participants. Respondents who reported serious AEFI were contacted by telephone to discuss their report, ensure that appropriate clinical management had occurred if required and enquire whether symptoms had resolved. There was no formal feedback to respondents in this pilot but plans are underway to make Vaxtracker safety data available to the public on a website as the programme is expanded.