Active surveillance of 2017 seasonal influenza vaccine safety: an observational cohort study of individuals aged 6 months and older in Australia

Abstract

ObjectiveTo actively solicit adverse events experienced in the days following immunisation with quadrivalent inactivated influenza vaccine using Australia’s near real-time, participant-based vaccine safety surveillance system, AusVaxSafety.Design and settingObservational cohort study conducted in 194 sentinel surveillance immunisation sites (primary care, hospital and community-based clinics) across Australia.ParticipantsIndividuals aged ≥6 months who received a routine seasonal influenza vaccine at a participating site (n=102 911) and responded to a survey (via short message service or email) sent 3 days after vaccination about adverse events experienced (n=73 892; 71.8%).Main outcome measureNear real-time and cumulative participant-reported rates of any adverse event, fever or medical attendance experienced within 3 days after vaccination overall, by brand, age, pregnancy status and concomitant vaccine receipt.ResultsParticipant median age was 57 years (range: 6 months to 102 years); 58.1% (n=42 869) were female and 2.7% (n=2018) were pregnant. Near real-time fast initial response cumulative summation and Bayesian analyses of weekly event rates did not demonstrate a safety signal. Children aged 6 months to 4 years had higher event rates (522/6180; 8.4%) compared with older ages; participants aged ≥65 years reported fewer events (1695/28 154; 6.0%). There were no clinically significant differences in safety between brands, by age group or overall. Cumulative data analysis demonstrated that concomitant vaccination was associated with increased rates of fever (2.1% vs 0.8%) and medical attendance (0.8% vs 0.4%), although all rates were low and did not exceed expected levels.ConclusionsNovel, postmarketing AusVaxSafety surveillance demonstrated comparable and expected safety outcomes for the 2017 quadrivalent inactivated influenza vaccine brands used in Australia. These near real-time, participant-reported data are expected to encourage confidence in vaccine safety and promote uptake.

Adverse Events Following Measles-Mumps-Rubella-Varicella Vaccination and the Case of Seizures: A Post Marketing Active Surveillance in Puglia Italian Region, 2017–2018

“…A previous, similar observational study published by Huang W.T. et al, based on the telephone interview approach, estimated a very similar AEFIs reporting rate of 48 × 100 follow-up [38][39][40].…”

Enhanced passive safety surveillance of three marketed influenza vaccines in the UK and the Republic of Ireland during the 2017/18 season

“…15 Nevertheless, under-or differential reporting can still occur because reporting remains spontaneous, as noted in similar surveillance system designs. 3,[16][17][18] A further limitation was that slightly fewer than the targeted 1000 safety report cards were Abbreviations: AEI, adverse event of interest; CI, confidence interval; IIV4, quadrivalent split-virion inactivated influenza vaccine; PRAC, Pharmacovigilance Risk Assessment Committee; SmPC, Summary of Product Characteristics; −, not reported a Since the proportion of total reported ARs and AEIs could theoretically be >100%, 95% CIs were not calculated b Only ARs reported in ≥2 participants in NH Season 2017/18 are shown c Includes feeling of body temperature change or pyrexia d Frequencies: very common (≥10%); common (≥1% to <10%); uncommon (≥0.1% to <1%); rare (≥0.01% to <0.1%); very rare (<0.01%) e Pain (very common; ≥10%), erythema and swelling (common; ≥1% to <10%), warmth (uncommon; ≥0.1% to <1%) distributed to participants receiving IIV3-ID and IIV4, although the small difference was unlikely to affect the conclusions. However, children and adolescents receiving IIV3 and IIV4 were poorly represented, possibly due to several sites overestimating their potential to vaccinate younger age groups within the short surveillance period.…”

Challenges in implementing yearly enhanced safety surveillance of influenza vaccination in Europe: lessons learned and future perspectives

“…In Australia, the AusVaxSafety surveillance system that uses integrated software to identify and issue automated surveys via text messaging provides active near real-time surveillance capable of rapid data collection on a national level. 41 The FAST-Mum program has monitored the trivalent influenza vaccine safety in pregnant women in Western Australia since 2012, 42 while Vaxtracker (also web-based) monitors inactivated influenza vaccine in children in New South Wales. 43 In Canada, text messaging has been introduced in the CANVAS network as an alternative to conventional telephone interviews.…”