Published: 28 April 2021


Adverse events following immunisation with COVID-19 vaccines: Safety Report #4 – 27 March 2021


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 27 March 2021


New AEFI reports since last update

(151 new non-serious and 4 new serious)


No safety signals (potential safety issues) have been identified


Total doses administered



Total AEFI reports that were non-serious


Total AEFI reports that were serious


Total AEFI reports that were received


There were 151 new non-serious and 4 new serious cases reported since the last update. Two of the serious reports were allergic reactions and were managed appropriately. One was a report of reactogenicity type reactions (flu-like symptoms). The final serious report was for a seizure-type event.

AEFI reports received by prioritised ethnicity and vaccine dose, up to and including 27 March 2021

Ethnicitya Dose 1 Dose 2 Dose
Māori 16 0 1 17
Pacific Peoples 18 6 0 24
Asian 73 15 3 91
European/Other 173 24 6 203
Unknown 41 58 23 122
Total 321 103 33 457


  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.

AEFI reports received by age band and vaccine dose, up to and including 27 March 2021

Age Dose 1 Dose 2 Dose
10 - 19 years 13 1 0 14
20 - 29 years 88 22 6 116
30 - 39 years 70 24 8 102
40 - 49 years 58 26 4 88
50 - 59 years 64 21 5 90
60 - 69 years 23 2 5 30
70 - 79 years 2 0 1 3
80+ years 0 0 0 0
Unknown 3 7 4 14
Total 321 103 33 457

Top 10 most frequently reported AEFIs, any dosea, up to and including 27 March 2021

Reaction Number
Dizziness 120
Headache 111
Nausea 84
Fatigue 52
Fever 49
Myalgiab 37
Chills 33
Arm pain 31
Flu-like symptoms 31
Vasovagal/Syncopec 25


  1. Includes AEFIs reported for dose 1, dose 2 or dose unknown
  2. Myalgia: muscle pain
  3. Vasovagal/Syncope: fainting

Top 10 most frequently reported AEFIs, dose 1 only, up to and including 27 March 2021

Reaction Number
Dizziness 91
Headache 57
Nausea 52
Vasovagal/Syncopea 25
Faintness 20
Fatigue 19
Fever 14
Flu-like symptoms 12
Myalgiab 11
Swelling 11


  1. Vasovagal/Syncope: fainting
  2. Myalgia: muscle pain

Top 10 most frequently reported AEFIs, dose 2 only, up to and including 27 March 2021

Reaction Number
Headache 40
Fever 27
Fatigue 24
Nausea 24
Chills 23
Dizziness 21
Myalgiaa 21
Musculoskeletal pain 19
Flu-like symptoms 17
Arm pain 16


  1. Myalgia: muscle pain

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.


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

Hide menus
Show menus
0 1 2 4 5 6 7 9 [ /