Incidence of live-attenuated influenza vaccine administration beyond expiry date in children and adolescents aged 2–17 years in the UK: a population-based cohort study. Issue 7 (17th July 2017)

• Record Type: Journal Article
• Authors: Caspard, Herve; Wise, Robert P; Steffey, Amy; Brody, Robert S
• Is Part Of: BMJ open. Volume 7:Issue 7(2017)
• Publication Date: 2017-07-17
• Subjects: Influenza -- vaccination -- expiration date -- paediatric -- lot distribution data -- medication error; Medicine -- Research -- Periodicals; 610.72
• DOI: 10.1136/bmjopen-2017-016520
• Languages: English
• ISSNs: 2044-6055

Abstract

Abstract : Objectives: To estimate the proportion of live-attenuated influenza vaccine (LAIV) doses administered beyond expiry date in children and adolescents during influenza seasons 2013–2014 and 2014–2015 in the UK. Design: This was a retrospective cohort study. Two cohorts of children and adolescents who received LAIV from 1 September 2013 to 31 March 2014 and from 1 September 2014 to 31 March 2015 and aged 2–17 years at time of LAIV administration were identified from the Clinical Practice Research Datalink (CPRD). Setting: More than 500 primary care practices in the UK. Population: Proportions of vaccine doses administered beyond expiry date were assessed among 47 396 and 67 099 LAIV recipients with a documented vaccine lot identifier in influenza seasons 2013–2014 and 2014–2015, respectively. Intervention: None. Main outcome measure: Administrations of expired LAIV were ascertained by comparison of vaccination dates in CPRD records with expiration dates in AstraZeneca/MedImmune lot distribution data. Results: Overall, 245 LAIV recipients, 80 in 2013–2014 and 165 in 2014–2015, received a dose after its expiration date, yielding proportion estimates of 1.7 per 1000 doses (95% CI 1.3 to 2.1) in season 2013–2014 and 2.5 per 1000 doses (95% CI 2.1 to 2.8) in season 2014–2015. This proportion increased above 1.0% after December during each season. Most (84% in influenza season 2013–2014 and 59% in influenza season 2014–2015) received an expired dose <30 days after its expiration date. The proportion was higher in London (relative risk 1.93 (95% CI 1.25 to 2.99)) and when the number of LAIV recipients registered in the practice was lower than the median number per practice (relative risk 2.69 (95% CI 1.99 to 3.62)). Conclusions: Administration of expired LAIV doses occurs infrequently.