Hazell1, S. Shakir* 1, J. Dentith2, E. Hammond3, D. Brooks3

1Drug Safety Research Unit, Southampton, 2AstraZeneca, Luton, United Kingdom, 3AstraZeneca, Gaithersburg, United States

Background

Fluenz® Tetra is a quadrivalent, live attenuated, intranasal, influenza vaccine recommended for use in children aged 2 to 17 years vaccinated as part of the seasonal influenza immunisation campaign in the UK.[1] Here, we present results from a third season of passive enhanced safety surveillance (ESS) for the vaccine in 2017-2018.

Objective

To measure and assess the frequencies of suspected adverse drug reactions (sADRs) in children receiving Fluenz® Tetra during the early 2017-2018 influenza season in England.

Methods

Vaccinees or parents/guardians received a Safety Report Card (SRC) to return if children experienced sADRs after vaccination with Fluenz® Tetra. At participating sites, 38 general practices and 36 primary schools in England, immunisation teams recorded numbers of SRCs distributed. The study was approved by an NHS Research Ethics Committee (Hampshire B South Central NRES Committee).

Results

Between 29th September 2017 and 2nd December 2017, 12,193 children were vaccinated at study sites, with 16 different vaccine lots used. In total, 10,793 SRCs were issued for children aged 2 to 17 including 5,189 children (48.1%) aged 2 to 4 years, 5,036 (46.7%) aged 5 to 10 years and 568 (5.3%) aged 11 to 17 years. Of 114 SRCs returned (by 9th January 2018 datalock), 101 reported at least one sADR (0.9% of all SRCs issued). The most frequently reported sADRs were rhinorrhoea (n=36), pyrexia (31) and cough (14). Three reported sADRs were classified as serious due to hospitalisation (0.03% of all SRCs issued) including nasal symptoms, general cold/flu symptoms and croup. The frequency of sADRs reported in the current ESS season was consistent with that reported in previous seasons.

Conclusion

Overall, the number of sADRs reported for Fluenz® Tetra in the 2017-2018 ESS remains low. Reported sADRs were typically minor expected events with serious sADRs rarely reported. The pattern and frequency of reported sADRs in the 2017-2018 season were consistent with previous seasons with no safety signals detected. Despite the limited number of reports received, the ESS method continues to be a useful extension to routine pharmacovigilance activities in the monitoring of possible sADRs.

Project sponsored by DSRU and AstraZeneca.

Reference

1. AstraZeneca. Fluenz® Tetra. Summary of Product Characteristics. Last updated: 22nd March 2018. Available at https://www.medicines.org.uk/emc/product/3296/smpc. Accessed: 9th May 2018