Published: 3 March 2016
Publications
Spontaneous Reports: Seasonal Influenza Vaccination 2015
Prescriber Update 37(1): 9-10
March 2016
In 2015, the Centre for Adverse Reactions Monitoring (CARM) received 241 reports of adverse events following seasonal influenza vaccination (Table 1). A total of 596 adverse events were described; many reports contained more than one suspected event.
Table 1: Number of reports received by CARM and number of influenza vaccine doses distributed, 2011-2015
| 2011 | 2012 | 2013 | 2014 | 2015 | |
|---|---|---|---|---|---|
| Reports of adverse events following influenza vaccination | 207 | 193 | 290 | 253 | 241 |
| Influenza vaccine doses distributed* | 993,500 | 1,000,600 | 1,253,600 | 1,206,573 | 1,211,152 |
| Estimated reporting rate per 100,000 doses | 20.8 | 19.3 | 23.1 | 21.0 | 19.9 |
*The number of doses distributed is not equal to number administered (eg, some doses may have been destroyed at the end of the influenza season and not used)
The most commonly reported events were injection site inflammation (57 reports), arm pain (33), headache (25), injection site pain (17) and pruritus (17).
At the beginning of the 2015 vaccination season, an increased proportion of reports of hypersensitivity and local reactions with the seasonal influenza vaccination were reported to CARM as compared with previous years ( www.medsafe.govt.nz/safety/EWS/2015/influenza-vaccine-hypersensitivity.asp). However by vaccination season end, the reported number of these reactions were comparable to previous years.
Fifteen (6%) of the influenza vaccine-related reports in 2015 were considered serious. A serious adverse reaction is defined, according to internationally agreed criteria, as any drug-related event that results in death, is life-threatening, requires or prolongs inpatient hospitalisation, results in persistent or significant disability or requires intervention to prevent permanent disability, is a congenital abnormality or is a medically important event.
Two deaths with a temporal association to the 2015 influenza vaccination were reported to CARM. One patient had a terminal condition and the reporter did not consider the vaccine to be a causal factor. The second patient, with a history of myocardial ischaemia and congestive cardiac failure, died of a sudden cardiac event.
In 2015, the majority of reports were submitted by nurses (71%), followed by GPs (18%) and pharmacists (5%). This reporter pattern is similar to previous years.
