Date of ISAC Approval:
Live attenuated influenza vaccine (LAIV) is approved for use in children and adolescents 2 to 17 years of age. Because it contains live substances, the vaccine has to be used before the expiration date printed on the label. Reports of using vaccine after its expiration date are received in January or February of each year. However, the number of these reports is still very small and it is likely that a large proportion of administrations of expired doses are not spontaneously reported. The objective of this study is to estimate the risk that children receive expired doses of LAIV in a group that represents the experience for all of the United Kingdom. Through use of data from CPRD, which is representative of the experience of the United Kingdom population, this study should provide a valid estimate of the risk that children receive expired doses, identify ways to increase awareness and eventually decrease the risk of these errors.
The purpose of this study is to estimate the proportion of LAIV administrations that used expired product among children aged 2-17 years during the two most recent influenza seasons and to identify risk factors. In addition, the study will document the distribution of the number of days between expiration and vaccination date. Administration of expired LAIV will be identified by comparison of the vaccination date in the CPRD record with the corresponding lot expiration date from records maintained by the vaccine manufacturer. The proportion of individuals receiving expired vaccine and 95% CIs among all LAIV recipients will be calculated according to subject characteristics (age, gender, comorbidities, region, length of registration at the practice), physician practice characteristics (practice size, Health Service Area) and calendar time. Predictors of administration of expired doses will be assessed by a multivariate regression to take into account potential confounders. Median intervals and measures of dispersion of the number of days between vaccination and vaccine expiration dates will also be described.
Health Outcomes to be Measured:
Use of expired live attenuated influenza vaccine
Robert (Bob) Steven Brody - Chief Investigator - Astra Zeneca Inc - USA
Amy Steffey - Collaborator - Not from an Organisation
Herve Caspard - Corresponding Applicant - MedImmune
Robert Wise - Collaborator - MedImmune