Published: 9 June 2021


Adverse events following immunisation with COVID-19 vaccines: Safety Report #10 – 8 May 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 8 May 2021


New AEFI reports since last update

(539 new non-serious and 12 new serious)


New safety signal (potential safety issue) has 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 539 non-serious and 12 serious reports this week. Four of the serious reports described allergic reactions. There was one report each for: chest discomfort, Bell’s Palsy, seizure, myocarditis, vertigo and hearing loss. Sadly, we are also reporting the deaths of two elderly individuals this week. Both deaths are considered by CARM, Medsafe and medical staff involved to be unrelated to the administration of Comirnaty but were reported through an abundance of caution.

There were also two reports of breastfed infants becoming unwell after their mother received the vaccine. One of the infants had an allergic reaction and the other infant had flu-like symptoms. Note that because these infants did not receive the vaccine, they are not included in the AEFI tables below.


Of the 4 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 2 and one case was possible Brighton anaphylaxis level 5.

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: herpes zoster (shingles)

Cases of herpes zoster following COVID-19 vaccination have been reported in New Zealand and internationally. Thus far, 7 cases of herpes zoster have been detected in New Zealand. So far, a causal link has not been established. Medsafe will continue to monitor this signal through our usual safety monitoring processes.

Ongoing safety signal: myocarditis

Cases of myocarditis have been reported in the past, including one this week. Medsafe is currently reviewing this signal and we will provide further information once the review is completed.

AEFI reports received by prioritised ethnicity and vaccine dose, up to and including 8 May 2021

Ethnicitya Dose 1 Dose 2 Dose
Māori 116 59 0 175
Pacific Peoples 89 66 0 155
Asian 320 196 0 516
European/Other 1,066 665 0 1,731
Unknown 35 21 0 56
Total 1,626 1,005 0 2,631


  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 56 AEFI reports where the person’s ethnicity was 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 8 May 2021

Age Dose 1 Dose 2 Dose
10 - 19 years 48 11 0 59
20 - 29 years 354 214 0 568
30 - 39 years 355 251 0 606
40 - 49 years 296 233 0 529
50 - 59 years 308 191 0 499
60 - 69 years 176 84 0 260
70 - 79 years 52 10 0 62
80+ years 22 4 0 26
Unknown 15 7 0 22
Total 1,626 1,005 0 2,631


  1. There were 22 AEFI reports where the person’s age was 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 8 May 2021

Reaction Number
Headache 936
Dizziness 770
Injection site pain 659
Nausea 616
Lethargy 523
Fever 425
Flu-like illness 381
Musculoskeletal pain 251
Feeling hot and cold 181
Muscle pain 159

Top 10 most frequently reported AEFIs, dose 1 only, up to and including 8 May 2021

Reaction Number
Dizziness 521
Headache 460
Nausea 333
Injection site pain 322
Lethargy 217
Flu-like illness 155
Fever 137
Syncopea 104
Numbness 89
Musculoskeletal pain 82


  1. Syncope: fainting

Top 10 most frequently reported AEFIs, dose 2 only, up to and including 8 May 2021

Reaction Number
Headache 476
Injection site pain 337
Lethargy 306
Fever 288
Nausea 283
Dizziness 249
Flu-like illness 226
Musculoskeletal pain 209
Feeling hot and cold 130
Localised enlarged lymph nodea 98


  1. Localised enlarged lymph node: swollen glands

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

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