Published: 27 July 2022

Safety Information

Spontaneous reports: Seasonal influenza vaccination 2021

Influenza vaccines distributed in 2021
Spontaneous reports received in 2021
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Influenza vaccines distributed in 2021

The 2021 Influenza Immunisation Programme started on 14 April 2021 with Fluad Quad for people aged 65 years and older. The programme for younger people began on 17 May 2021 with Afluria Quad, Afluria Quad Junior and Influvac Tetra. More than 1.4 million doses of influenza vaccine were distributed in 2021 (Table 1).

Spontaneous reports received in 2021

The Centre for Adverse Reactions Monitoring (CARM) received 425 reports of suspected adverse reactions to the influenza vaccine in 2021 (Table 1). Compared to previous years, there was a significant increase in the number of reports and the estimated reporting rate in 2021. The COVID-19 Immunisation Programme was also rolled out in 2021 and may have raised awareness of reporting suspected adverse reactions.

There were 1,007 reactions described in the reports. The most commonly reported adverse reactions were injection site inflammation, injection site pain, arm pain, nausea and dizziness (Table 2).

Of the 425 reports, 10.8 percent were considered serious. A serious adverse reaction is defined as any reaction that results in death or is life-threatening, causes or prolongs hospitalisation, results in persistent or significant disability/incapacity, is a congenital abnormality or is a medically important event. Two deaths with a temporal association to the 2021 influenza vaccination were reported to CARM. Causality assessment did not reveal a link to the vaccine for either of the deaths.

As in previous years, nurses submitted most reports (63.3%). Pharmacists (14.4%) and GPs (12%) were the next largest groups of reporters, followed by consumers (7.8%).

Table 1: Number of reports of adverse events following influenza vaccination received by the Centre for Adverse Reactions Monitoring and number of influenza doses distributed, 2017–2021

	2017	2018	2019	2020	2021
Number of adverse event reports following influenza vaccinationa	191	232	229	275	425
Influenza vaccine doses distributedb,c	1,217,169	1,317,197	1,505,268	1,774,269	1,432,618
Estimated reporting rate per 100,000 doses distributed	15.7	17.6	15.2	15.5	29.7

Notes:

1. Source: Centre for Adverse Reactions Monitoring
2. Sources: Manatū Hauora – Ministry of Health and Te Whatu Hauora – Health New Zealand
3. The number of doses distributed is not equal to the number of people who received the vaccine

Table 2: Top five reported suspected adverse reactions for seasonal influenza vaccines, 2021

Adverse reaction	Number	Percentage of total reactions (n=1,007)	Percentage of total reports (n=425)
Injection site inflammation	65	6.5	15.3
Injection site pain	62	6.2	14.6
Arm pain	59	5.9	13.9
Nausea	36	3.6	8.5
Dizziness	29	2.9	6.8

More information

Manatū Hauora – Ministry of Health information about influenza
How Medsafe monitors vaccine safety
Report a suspected adverse reaction to CARM