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COVID-19 vaccine weekly safety report - 30-09-2021

Vaccination against COVID-19 is the most effective way to reduce deaths and severe illness from infection. Millions of people have received COVID-19 vaccines under the most intense safety monitoring ever conducted in Australia. 

Three COVID-19 vaccines are currently in use in Australia – Vaxzevria (AstraZeneca), Comirnaty (Pfizer) and Spikevax (Moderna). To be registered for use, these vaccines have met the TGA’s high standards for quality, safety and effectiveness.

Like all medicines, COVID-19 vaccines may have some side effects (also known as adverse events). The overwhelming majority of these side effects are mild and resolve within a few days. More serious side effects can occur after vaccination but are very rare.

The TGA closely monitors reports of suspected side effects to the COVID-19 vaccines and provides regular updates on vaccine safety in this report. Find out how the TGA identifies and responds to a safety concern

Importantly, suspected adverse events reported to the TGA are often not caused by the vaccines. Learn more about causality and the TGA’s COVID-19 vaccine safety monitoring and reporting activities. 

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Summary

  • The protective benefits of vaccination against COVID-19 far outweigh the potential risks of vaccination. 

  • To 26 September 2021, approximately 26.8 million vaccine doses have been given in Australia – 16.1 million first doses and 10.7 million second doses.

  • The most frequently reported side effects suspected to be associated with the vaccines reflect what was seen in the clinical trials. They include injection-site reactions such as a sore arm, and more general symptoms such as headache, muscle pain, fever and chills.

  • We are closely monitoring rare reports of blood clots with low blood platelets (also called thrombosis with thrombocytopenia syndrome or TTS) linked to Vaxzevria (AstraZeneca).

  • In the last week, an additional 7 reports of blood clots and low blood platelets have been assessed as confirmed or probable TTS, bringing the total number of cases to 148.

  • We also continue to carefully monitor reports of suspected myocarditis following the Comirnaty (Pfizer) vaccine, particularly in the younger age groups. To 26 September 2021, we have received 115 reports which were classified as likely to be myocarditis.

  • The Spikevax (Moderna) vaccine is now being rolled out in Australia. To 26 September 2021, we have received 5 reports of suspected adverse events.

Reported side effects for COVID-19 vaccines

Gathering reports of adverse events following immunisation (AEFI) is just the first step in determining whether the effect is related to the vaccine and whether a significant safety issue is involved. Learn more about how the TGA identifies and responds to safety issues

In the general population (16 years of age and over), the most frequently reported side effects suspected to be associated with the vaccines include injection-site reactions such as a sore arm, and more general symptoms such as headache, muscle and joint pain, and fever and chills.

Now the vaccines are being rolled out more widely, we are receiving more reports in younger individuals. The TGA is monitoring these reports closely. We know from the Comirnaty (Pfizer) and Spikevax (Moderna) clinical trials that the most common adverse reactions in adolescents are similar to those in older people and include injection-site pain, fatigue and headache. Most of these side effects were mild and resolved within a day or two. For both vaccines, they were more common after the second vaccine dose than the first. 

To help us monitor the safety of the COVID-19 vaccines, we encourage people to report suspected side effects even if there is only a small chance that the vaccine caused them. You can also participate in the AusVaxSafety COVID-19 vaccine surveillance program by completing a short survey after receiving your COVID-19 vaccination.  The survey is available through state immunisation clinics and other participating vaccine providers. Information collected from the survey is published each week on the AusVaxSafety website and complements our ongoing safety surveillance activities at the TGA.

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Total adverse event reports to 26 September 2021

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2.4
Reporting rate per 1000 doses
64,293
Total AEFI reports received
26,806,343
Total doses administered
37,049
Total reports for Vaxzevria
26,921
Total reports for Comirnaty
5
Total reports for Spikevax
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To 26 September 2021, the total number of adverse event reports received where the brand of the COVID-19 vaccine was not specified was 361.

Reporting rates per 1000 doses by jurisdiction

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1.7
Australian Capital Territory
1.6
New South Wales
2.3
Northern Territory
2.4
Queensland
2.4
South Australia
4.2
Tasmania
3.3
Victoria
2.3
Western Australia

Reports of death in people who have been vaccinated

Large scale vaccination means that coincidentally some people will experience a new illness or die within a few days or weeks of vaccination. 

The TGA reviews all deaths reported in people who have been vaccinated. As the number of vaccinated people has increased, so has reporting of fatal events with a coincidental association with vaccination. This does not indicate a link between vaccination and the fatalities reported. Review of individual reports and patterns of reporting does not suggest the vaccines played a role in these deaths.

Since the beginning of the vaccine rollout to 26 September 2021, over 26.8 million doses of COVID-19 vaccines have been given. So far, the TGA has found 9 reports of death that were linked to immunisation from 564 reports received and reviewed. The overwhelming majority of deaths reported to the TGA following vaccination occurred in people aged 65 years and older. The deaths linked to immunisation occurred after the first dose of Vaxzevria (AstraZeneca) – 8 were TTS cases and one was a case of immune thrombocytopenia (ITP).

Spikevax (Moderna) vaccine

The Spikevax (Moderna) vaccine is now being rolled out in Australia. To 26 September 2021, approximately 36,000 doses have been given. We have received 5 reports of suspected adverse events associated with the vaccine. These were expected reactions consistent with what has been reported in the trials and included injection-site reactions, fever, dizziness and fainting. 


Up-to-date information about the expected side effects of Spikevax (Moderna) can be found in the Consumer Medicine Information (for consumers) and Product Information (for health professionals).

Vaxzevria (AstraZeneca) vaccine

To 26 September 2021, approximately 11.6 million doses of Vaxzevria (AstraZeneca) have been administered in Australia. The reports of suspected side effects we receive for this vaccine are consistent with what has been observed in the clinical trials and by other medicine regulators overseas. Most side effects resolve within a few days.

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Thrombosis with thrombocytopenia syndrome (TTS)

We are closely monitoring rare reports of blood clots with low blood platelets (also called thrombosis with thrombocytopenia syndrome or TTS) linked to Vaxzevria (AstraZeneca). 

Early detection of TTS may help to prevent more serious complications developing. Guidance for health professionals is now available which outlines when to suspect TTS, initial tests that can be performed in primary care and when to refer people for emergency care. Patients presenting with low platelets and a headache should be thoroughly investigated for blood clots in the brain, including careful review of imaging results to identify early, small clots. The Royal Australian and New Zealand College of Radiologists have published imaging recommendations for patients with suspected TTS.

People should seek immediate medical attention if they develop any of the following symptoms after vaccination:

  • severe or persistent headache, blurred vision, confusion or seizures

  • shortness of breath, chest pain, leg swelling or persistent abdominal pain

  • unusual skin bruising and/or pinpoint round spots beyond the site of vaccination.

The most common time period for onset of TTS symptoms is 4–30 days after vaccination.

To date, there have been 148 cases of TTS assessed as related to Vaxzevria (AstraZeneca) from approximately 11.6 million vaccine doses. These cases most often occurred about 2-3 weeks after vaccination. The risk of TTS after a second dose appears to be much lower than after the first dose. Women in younger age groups seem to be slightly more likely to develop clots in unusual locations, such as the brain or abdomen, which have more serious outcomes. Eight people have died as a result of TTS – 6 of these were women. In Australia, the risk of dying from TTS after vaccination is approximately 1 in a million (people receiving a first dose), and somewhat less than this when both doses are taken into consideration.

While TTS is very rare, some people may have concerns that they can discuss with their doctor. ‘Weighing up the potential benefits against risk of harm from COVID-19 Vaccine AstraZeneca’ includes information to help people make informed decisions about vaccination.

Details of TTS cases to date

Since last week’s report, a further 7 reports of blood clots and low blood platelets have been assessed as confirmed or probable TTS likely to be linked to the first dose of Vaxzevria (AstraZeneca). Four of the new confirmed cases of TTS reported this week were in individuals aged under 60 years (Table 1). Three of these individuals have been discharged from hospital, but one person remains critically unwell in intensive care. We continue to closely monitor cases of TTS as Vaxzevria (AstraZeneca) is now being used more frequently in people aged under 60 years. To date, we have not observed a significant change in the rate of TTS in people aged 50-59 years. There has been a trend for the rate to decrease in people under 50-years, but due to the low number of cases this is not statistically significant. 

Table 1: Newly confirmed and probable TTS cases for the week of 24-30 September 2021‡

New confirmed TTS

New probable TTS

Six new cases:

  • 19-year-old woman from Victoria

  • 39, 52 and 66-year old men from NSW

  • 57-year-old woman from NSW

  • 89-year-old man from Queensland

One new case:

  • 76-year-old woman from NSW

As previously reported, the TGA determines whether a report is likely to represent TTS by assessing cases against accepted criteria established by the UK’s Medicines and Healthcare products Regulatory Agency. 

This takes the total Australian reports assessed as TTS following Vaxzevria (AstraZeneca) to 148 cases (83 confirmed, 65 probable) from approximately 11.6 million vaccine doses.

To date, 16 cases of TTS have occurred after the second dose. Twelve cases have been classified as probable TTS, with 4 cases meeting the criteria for confirmed TTS. All cases have occurred in individuals older than 50 years, with 13 of the cases in people over 60 years of age. Thirteen of the patients had clots in common locations, such as the lungs or legs, with only 3 cases classified as the more serious Tier 1 (see below). The information available to us indicates that only one of these patients required treatment in the intensive care unit, and 13 individuals have been discharged from hospital. Our preliminary analysis is consistent with overseas investigations which have shown that the risk of TTS after the second dose is extremely low (for example, 1.9 cases per million based on data from the UK). 

When assessed against the criteria used by the US Centers for Disease Control and Prevention (CDC), fewer than half of the cases reported to the TGA are classified as Tier 1 cases which tend to have more serious outcomes. Tier 1 cases involve clots in an unusual location, such as the brain or abdomen (Table 2). Australian data indicates that patients aged under 50 years of age are more likely to be classified as Tier 1 and/or require treatment in intensive care. However, more than one third of these younger patients have not required treatment in intensive care. 

Table 2: Total confirmed and probable TTS cases to date by age and CDC classification

Age

Total cases

Reports per 

100,000 doses‡

CDC classification†

Tier 1

Tier 2

Not classified

<30 years

7

1.8 

(<50 years)

2

3

2

30-39

5

4

1

-

40-49

8

6

1

1

50-59

35

3.0

18

11

6

60-69

35

1.6

11

9

15

70-79

40

2.0

10

12

18

80+

18

2.0

8

6

All ages

148

(74 men,

74 women)

2.0

55

(20 men, 

35 women)

45

(28 men, 

17 women)

48

(26 men, 

22 women)

‡ Rates of TTS are calculated based on first doses of the Vaxzevria (AstraZeneca) vaccine as of 19 August to account for the time to onset of TTS. These rates are estimates of risk based on small numbers of cases so far.

† The US CDC classification is defined as:

  • Tier 1 = clots in an unusual location (such as the brain or abdomen) and a low platelet count with or without antibodies that activate platelets (anti-PF4 antibodies)

  • Tier 2 = clots found in common locations (such as the leg or lungs) and a low platelet count and anti-PF4 antibodies

  • Not classified = case does not meet the criteria for Tier 1 or Tier 2 (for example clots in common locations with low platelet count but no evidence of anti-PF4 antibodies).

Cases have most often occurred about 2 weeks after vaccination, although the time to onset (or diagnosis) has ranged from one to 100 days (Table 3).

Table 3: Time to onset, treatment and outcomes for TTS cases*

Time to onset/ diagnosis (days)

Median (range)

18 (1-100)

Treated in ICU

At any point

44

Currently

1

Outcome

Discharged

129

In hospital

11

Fatal

8

*Data is based on the most recent medical information available to the TGA

Other safety signals with Vaxzevria (AstraZeneca)

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Guillain-Barre Syndrome (GBS)

GBS is a rare immune disorder affecting the nerves and can result in pain, numbness, muscle weakness and difficulty walking. It has been associated with COVID-19 infection as well as other infectious diseases. Following rigorous investigations by the TGA and other international drug regulators, a clear link between GBS and Vaxzevria (AstraZeneca) has not been established. However as a precautionary measure, a warning statement about GBS has been added to the Product Information in response to rare cases following vaccination.

To 26 September 2021, the TGA has received 129 reports of suspected GBS occurring after vaccination with Vaxzevria (AstraZeneca). These cases will be considered as part of our ongoing monitoring of this safety signal. It is expected that some suspected cases may not be related to vaccination, as GBS can also be caused by other common causes of GBS, such as viral infections and some types of gastroenteritis. 

We encourage people to seek medical attention if they experience symptoms that could suggest GBS as early medical care can reduce severity and improve outcomes. Symptoms to look out for include weakness and paralysis in the hands or feet that can progress to the chest and face over a few days or weeks. These tend to affect both sides of the body.

Immune thrombocytopenia (ITP)

The TGA continues to monitor and investigate reports of suspected ITP, a type of thrombocytopenia or low platelet count. We will communicate the outcomes of this investigation, including any regulatory actions, when it is complete. 

To 26 September 2021, the TGA has received 75 reports of suspected ITP following vaccination. These patients had an extremely low platelet count, and signs of thrombocytopenia which may include unusual bruising, a nosebleed and/or blood blisters in the mouth. Their symptoms occurred in a timeframe that suggested they could be linked to vaccination and no other obvious cause was identified based on the information provided to TGA. Apart from one fatal case that was assessed by an expert Vaccine Safety Investigation Group as being likely to be vaccine related, suspected cases of ITP have not been definitively linked to vaccination.

ITP can occur when the immune system is activated, for example by a viral infection or vaccination, and mistakenly destroys platelets which help blood to clot. In many cases it is mild with up to a third of people having no symptoms at all, or only minor bruising. However, about 5% develop severe bleeding. 

We encourage people to seek medical attention if they experience signs and symptoms that could suggest ITP, such as unusual skin bruising or clusters of small red or purple spots that do not lose their colour when pressed. Unusual bleeding is another sign, for example bleeding from the nose or mouth that is hard to stop, or blood in the urine or stools.


Up-to-date information about the expected side effects of Vaxzevria (AstraZeneca) can be found in the Consumer Medicine Information (for consumers) and Product Information (for health professionals).

Comirnaty (Pfizer) vaccine

To 26 September 2021, approximately 15.1 million doses of Comirnaty (Pfizer) have been administered in Australia. The reports of suspected side effects we receive for this vaccine are consistent with what has been observed in the clinical trials and by other medicine regulators overseas. Most side effects resolve within a few days.

The TGA is actively monitoring myocarditis (inflammation of the heart) and pericarditis (inflammation of the membrane around the heart) and continues to work with international regulators on this safety signal.

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Myocarditis and pericarditis

Myocarditis and pericarditis are rare effects on the heart that can occur within 10 days of vaccination with the mRNA vaccines Comirnaty (Pfizer) and Spikevax (Moderna). Cases are usually transient and resolve following treatment and rest. 

Myocarditis is seen much more commonly in people who become infected with COVID-19 than in people who are vaccinated and the Australian Technical Advisory Group on Immunisation (ATAGI) continues to emphasise the protective benefits of the mRNA vaccines far outweigh the rare risk of these side effects in all eligible age groups

We encourage people to seek medical attention if they experience symptoms that could suggest myocarditis or pericarditis. This includes chest pain, palpitations (irregular heartbeat), fainting or shortness of breath after receiving the vaccine, particularly if they occur within 1–5 days. 

Initial tests for those presenting with symptoms include ECG, troponin and chest X-ray. Brief guidance on the initial assessment of children and adolescents with symptoms has been published by the Paediatric Research in Emergency Departments International Collaborative (PREDICT) network

ATAGI advises that people who develop myocarditis or pericarditis attributed to their first dose of Comirnaty (Pfizer) should defer further doses of an mRNA COVID-19 vaccine and discuss this with their treating doctor. 

For more information, see guidance on myocarditis and pericarditis developed by ATAGI and the Cardiac Society of Australia and New Zealand (CSANZ).
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Details of Australian cases to date

Our analysis of Australian data indicates there is a higher-than-expected number of cases of myocarditis in vaccinated compared to unvaccinated individuals. This is similar to findings from other drug regulators overseas. 

To 26 September 2021, we have received 850 reports of suspected myocarditis and/or pericarditis following vaccination with the Comirnaty (Pfizer) vaccine. These effects can occur due to other causes, including common viral infections, so it is expected that not all of these cases are related to vaccination.

Of the reports received, 178 reported suspected myocarditis. We have reviewed these cases against an internationally accepted case definition for myocarditis to classify how certain it is that these cases reflect myocarditis. This assessment does not determine whether cases have been caused by vaccination.

Cases considered to be highly likely to be myocarditis, based on strong clinical evidence, are classified as level 1. We are less certain that cases classified as level 2 or 3 represent myocarditis. These have less information and may be supported only by the patient’s symptoms and limited test results or the treating doctor’s view. Of the 178 suspected cases:

  • 115 were classified as likely to be myocarditis (4 were level 1, 46 were level 2 and 65 reports were level 3) 

  • 21 were deemed unlikely to be myocarditis

  • 42 could not be classified because they did not contain enough information 

Cases classified as likely to be myocarditis (levels 1-3) were reported in patients aged between 16 and 60 years old (Table 4). As myocarditis has other causes, including viral infections, not all of these confirmed cases will be related to vaccination. 

In Australia it is estimated that there would normally be one case of myocarditis diagnosed each week in people aged 0-19 years. This can be higher in the winter months when viral infections are more common.

Table 4. Total cases classified as likely to be myocarditis (levels 1-3) to 26 September 2021

Age (years)

All doses

Second doses

Total cases

Rate* per 100,000 doses

Total cases

Rate* per 100,000 doses

≤19†

17

1.4

11

4.7

20-29

20

0.7

13

1.5

30-39

23

0.7

6

0.5

40-49

34

0.8

20

1.1

50-59

15

0.6

3

0.3

60-69

1

0.2

0

0

70+

0

0

0

0

Age unknown

5

--

2

--

All ages

115

0.7

55

1.0

*The rate includes cases of myocarditis that occurred after vaccination but may not be vaccine-related. The number of younger people vaccinated is still relatively low in Australia, so estimated reporting rates are based on limited data.

†The youngest case classified as ‘likely myocarditis’ to date was 16 years. 

Most of the patients with myocarditis experienced symptoms within 3 days of vaccination. Just over half required treatment in hospital but most were discharged within 4 days.

Preliminary analysis of the likely myocarditis cases suggests they are reported more frequently in teenage boys after the second dose. This has been observed in other countries including in the US where a large number of doses have been given, including in children. The estimated reporting rates in Australia appear similar to overseas rates.

We continue to monitor and review Australian data on myocarditis and will provide regular updates in this report as more information becomes available.


Up-to-date information about Comirnaty (Pfizer) can be found in the Consumer Medicine Information (for consumers) and Product Information (for health professionals).