Published: 19 May 2021
Archived: 21 August 2024

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COVID-19 Archive

Adverse events following immunisation with COVID-19 vaccines: Safety Report #7 – 17 April 2021

• Introduction
• Adverse events following immunisation (AEFI) reported
• Definitions
• More information

Introduction

This page provides information on the number of adverse events following immunisation (AEFI) reports received for COVID-19 vaccines.

The national roll-out of COVID-19 vaccines commenced on 20 February 2021. The vaccine currently available in New Zealand is Pfizer-BioNTech (Comirnaty). All medicines can cause side effects, the known side effects for Comirnaty are listed in the data sheet and consumer medicine information.

Suspected AEFI to COVID-19 vaccines are reported to the Centre for Adverse Reactions Monitoring (CARM). The Ministry of Health (through Medsafe) contracts the collection of this information to CARM, based at the University of Otago in Dunedin. Medsafe is closely monitoring the AEFI reported from the use of the COVID-19 vaccine. Find out more about vaccine safety monitoring.

Adverse events following immunisation (AEFI) reported

The information below includes:

• AEFI reports received and vaccine doses administered
• AEFI reports by prioritised ethnicity and vaccine dose
• AEFI reports by age band and vaccine dose
• the top 10 most frequently reported AEFIs by vaccine dose.

AEFI reports received and vaccine doses administered, up to and including 17 April 2021

There were 322 non-serious and 25 serious reports this week. Twelve of the serious reports were for allergic reactions and 8 were for reactogenicity reactions (flu-like symptoms). The remaining serious reports were for brain blood clot, amnesia, tinnitus (ear ringing), abnormal blood test, and appendicitis. The brain blood clot and appendicitis cases are further discussed below.

Anaphylaxis

Of the 12 reports of allergic reactions this week, there were 2 reports where the reporter indicated suspected anaphylaxis. CARM assessed these cases against the Brighton Collaboration case definition for anaphylaxis. One case was possible Brighton anaphylaxis level 3 and the other case was possible Brighton anaphylaxis level 2.

Anaphylaxis is a rare adverse event that can occur with any vaccine. People giving vaccines must have medical treatment for anaphylaxis on hand, and must keep people under observation for at least 20 minutes so that anaphylaxis can be managed, if it happens.

New safety signal: appendicitis

There was one serious report of appendicitis this week. Medsafe’s initial review of this report is that the appendicitis is not related to vaccination. We will continue monitor appendicitis through our usual safety monitoring processes.

Being monitored: blood clots

There was one report of cerebral venous sinus thrombosis (brain blood clot) this week. This report was reviewed by CARM and the COVID-19 Vaccine Independent Safety Monitoring Board (CV-ISMB) on 22 April 2021. The report was not considered to be related to vaccination. Medsafe continues to monitor this safety signal and remains in contact with international regulators. See Medsafe’s monitoring communication for more information.

AEFI reports received by prioritised ethnicity and vaccine dose, up to and including 17 April 2021

Ethnicitya	Dose 1	Dose 2	Dose unknownb	Total
Māori	65	22	0	87
Pacific Peoples	48	34	0	82
Asian	189	63	0	252
European/Other	588	228	0	816
Unknown	14	11	2	27
Total	904	358	2	1264

Note:

1. The prioritised ethnicity classification system allocates each person to a single ethnic group, based on the ethnic groups they identify with. Where people identify with more than one group, they are assigned in this order of priority: Māori, Pacific Peoples, Asian, and European/Other. So, if a person identifies as being Māori and New Zealand European, the person is counted as Māori. See Ethnicity Data Protocols for further information.
2. There were 27 AEFI reports where the person’s ethnicity was not reported, including 2 reports where both the ethnicity and vaccine dose number were not reported. Ethnicity and dose number are not required for an AEFI report to be considered valid. See ‘Valid report’ in the Definitions section below.

AEFI reports received by age band and vaccine dose, up to and including 17 April 2021

Age	Dose 1	Dose 2	Dose unknowna	Total
10 - 19 years	32	2	0	34
20 - 29 years	222	91	0	313
30 - 39 years	202	83	0	285
40 - 49 years	167	85	0	252
50 - 59 years	164	66	0	230
60 - 69 years	87	28	0	115
70 - 79 years	23	1	0	24
80+ years	7	1	0	8
Unknown	0	1	2	3
Total	904	358	2	1264

Notes:

1. There were 3 AEFI reports where the person’s age was not reported, including 2 reports where both the age and vaccine dose number were not reported. Age and dose number are not required for an AEFI report to be considered valid. See ‘Valid report’ in the Definitions section below.

Top 10 most frequently reported AEFIs, any dose, up to and including 17 April 2021

Reaction	Number
Headache	351
Dizziness	313
Nausea	245
Injection site pain	198
Lethargy	138
Fever	123
Flu-like illness	110
Muscle pain	106
Joint pain	67
Musculoskeletal pain	65

Top 10 most frequently reported AEFIs, dose 1 only, up to and including 17 April 2021

Reaction	Number
Dizziness	249
Headache	207
Nausea	157
Injection site pain	129
Lethargy	71
Flu-like illness	57
Fever	53
Muscle pain	44
Syncopea	44
Chest discomfort	30

Note:

1. Syncope: fainting

Top 10 most frequently reported AEFIs, dose 2 only, up to and including 17 April 2021

Reaction	Number
Headache	144
Nausea	88
Fever	70
Injection site pain	69
Lethargy	67
Dizziness	64
Muscle pain	62
Flu-like illness	53
Musculoskeletal pain	44
Joint pain	43

Please note that one adverse event report, which represents one person, may report on more than one symptom. Reports are sent to CARM if the reporter suspects that the vaccine may have caused the event. This does not necessarily mean that the vaccine did cause the event.

The number of reports can be influenced by how many people are being vaccinated, media attention, the nature of the events (eg, how painful the vaccination was), and other factors which vary over time. Not everyone who has an adverse reaction reports it, and some people may report AEFIs after each vaccination. The information here shows the number of reports not the number of people who experienced an AEFI.

The information is limited by the information provided in the report and may change over time due to quality control procedures and/or receipt of additional information. Non-valid reports are not included in the data.

Medsafe and CARM thank everyone who has contributed to the monitoring of COVID-19 vaccines. Please continue to report any adverse events following immunisation.

Definitions

Adverse event following immunisation (AEFI)

An AEFI is an untoward medical event which follows immunisation and does not necessarily have a causal relationship with the administration of the vaccine. The adverse event may be an unfavourable or unintended sign, abnormal laboratory finding, symptom or disease.

Serious adverse event following immunisation

An AEFI is considered serious if it:

• is a medically important event or reaction
• requires hospitalisation or prolongs an existing hospitalisation
• causes persistent or significant disability or incapacity
• is life threatening
• causes a congenital anomaly/birth defect
• results in death.

It is possible for different people to have experienced the same event but for the report to be serious for one person and non-serious for another person.

Safety signal

Information on a new or known adverse event that may be caused by the vaccine and requires further investigation. Safety signals can be detected from a wide range of sources such as CARM reports, clinical studies and scientific literature.

Valid report

There are only four requirements for a valid AEFI report:

1. one patient identifier (eg, name, initials, gender, date of birth, age)
2. suspect medicine(s)
3. suspected reaction(s)
4. reporter details.

These four requirements are the minimum requirements. However, including more information in the report helps Medsafe to investigate the reaction more quickly. Reporting is easiest online.

More information

See the data sheets and consumer medicine information for the expected reactions for approved COVID-19 vaccines.

COVID-19 Vaccine Safety Monitoring Process

View Ministry of Health COVID-19 vaccine data