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COVID-19 vaccine weekly safety report - 14-10-2021

Vaccination against COVID-19 is the most effective way to reduce deaths and severe illness from infection. Millions of people have now 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 must meet 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 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 10 October 2021, approximately 31 million vaccine doses have been given in Australia – 18 million first doses and 13 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, 2 additional reports of blood clots and low blood platelets have been assessed as probable TTS, bringing the total number of cases to 152.

  • We continue to carefully monitor reports of suspected myocarditis and pericarditis following the Comirnaty (Pfizer) and Spikevax (Moderna) vaccines, particularly in younger age groups. For Comirnaty (Pfizer), to 10 October 2021, we have received 269 reports of suspected myocarditis alone or in combination with pericarditis, and an additional 725 reports of suspected pericarditis alone. In the same period for Spikevax (Moderna), we have received one report of suspected myocarditis and 13 reports of suspected pericarditis. These events can occur due to other causes, including common viral infections, so it is expected that not all cases are related to vaccination.

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 under 18 years. 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 10 October 2021, we have received 856 reports in individuals under 18 years old after vaccination with Comirnaty (Pfizer) and Spikevax (Moderna). The most commonly reported reactions are dizziness, fainting (syncope) and feeling faint (pre-syncope), nausea and chest pain. However, at this point they are early observations based on limited data as we continue to closely monitor safety in this age group. 

To help us assess the safety of the COVID-19 vaccines, we encourage people to report suspected side effects even if it is not certain that the vaccine caused them. Anyone can report a suspected side effect including members of the public, nurses, pharmacists, doctors, health authorities and pharmaceutical companies. A report can be made directly to the TGA, through a health professional, or by calling the NPS MedicineWise Adverse Medicine Events phone line for consumers. Reporting can be anonymous if preferred. For more information click Report a suspected side effect.

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Total adverse event reports to 10 October 2021

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2.3
Reporting rate per 1000 doses
69,410
Total AEFI reports received
30,706,847
Total doses administered
38,338
Total reports for Vaxzevria
30,533
Total reports for Comirnaty
217
Total reports for Spikevax
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To 10 October 2021, the total number of adverse event reports received where the brand of the COVID-19 vaccine was not specified was 372.

Reporting rates per 1000 doses by jurisdiction

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1.5
Australian Capital Territory
1.5
New South Wales
2.3
Northern Territory
2.2
Queensland
2.3
South Australia
4.0
Tasmania
3.1
Victoria
2.2
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 10 October 2021, over 30.7 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 597 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).

Vaxzevria (AstraZeneca) vaccine

To 10 October 2021, approximately 12.5 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 152 cases of TTS assessed as related to Vaxzevria (AstraZeneca) from approximately 12.5 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.

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Details of TTS cases to date

Since last week’s report, 2 additional reports of blood clots and low blood platelets have been assessed as probable TTS likely to be linked to the first dose of Vaxzevria (AstraZeneca).  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 and the rates for people under 50 years and over 60 years are now similar.

Table 1: Newly confirmed and probable TTS cases for the week of 8-14 October 2021‡ 

New confirmed TTS

New probable TTS

No new cases.

Two new case:

  • 25-year-old woman from Queensland

  • 76-year-old man from Queensland

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. 

Following review of further information, one case reported last week was reclassified from probable to confirmed while another case was reclassified from probable to unlikely. This takes the total Australian reports assessed as TTS following Vaxzevria (AstraZeneca) to 152 cases (85 confirmed, 67 probable) from approximately 12.5 million vaccine doses.

To date, 18 cases of TTS have occurred after the second dose. Twelve cases have been classified as probable TTS, with 6 cases meeting the criteria for confirmed TTS. All cases have occurred in individuals older than 50 years, with 15 of the cases in people over 60 years of age. The vast majority of the patients had clots in common locations, such as the lungs or legs, with only 3 cases classified as Tier 1 (see below). The information available to us indicates that only one of these patients required treatment in the intensive care unit, and 15 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. 

When assessed against the criteria used by the US Centers for Disease Control and Prevention (CDC), approximately one third 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

8

1.9

(<50 years)

2

3

3

30-39

5

4

1

-

40-49

9

6

1

2

50-59

36

3.0

19

11

6

60-69

35

1.5

11

9

15

70-79

41

2.1

10

12

19

80+

18

1.7

9

5

All ages

152

(76 men,

76 women)

2.0

56

(20 men,

36 women)

46

(28 men,

18 women)

50

(28 men,

22 women)

‡ Rates of TTS are calculated based on first doses of the Vaxzevria (AstraZeneca) vaccine as of 30 September 2021 to account for the time to onset of TTS. These rates are estimates of risk based on small numbers of cases so far. An aggregated rate is given for people aged 18–49 years as the number of cases for each 10-year age bracket is too low to calculate reliable estimates.

 

† 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)

13 (1-100)

Treated in ICU

At any point

46

Currently

0

Outcome

Discharged

133

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 and 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 10 October 2021, the TGA has received 128 reports of suspected GBS occurring after vaccination with Vaxzevria (AstraZeneca). It is expected that not all of these cases are related to vaccination as GBS can occur after common 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 10 October 2021, the TGA has received 83 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 with no other obvious cause 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 and mistakenly destroys platelets which help blood to clot. This can happen sometimes after a viral infection or vaccination. 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).

Myocarditis and pericarditis with mRNA vaccines

Myocarditis (inflammation of the heart) and pericarditis (inflammation of the membrane around the heart) are rare effects on the heart that typically 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 that 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, particularly if they occur within 1–5 days of vaccination. 

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.

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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 for Comirnaty (Pfizer). This is similar to findings from other drug regulators overseas. 

To 10 October 2021 for Comirnaty (Pfizer), we have received 269 reports of suspected myocarditis alone or in combination with pericarditis, with 31 of these reports in adolescents (12-17 years-old). We have also received 725 reports of suspected pericarditis alone, with 37 of these reports in adolescents. In the same period for Spikevax (Moderna), we have received one report of suspected myocarditis and 13 reports of suspected pericarditis, all in adults. These events can occur due to other causes, including common viral infections, so it is expected that not all cases are related to vaccination.

As we have only limited reports for the Spikevax (Moderna) vaccine, our analysis focuses on data for the Comirnaty (Pfizer) vaccine. We have reviewed the 269 reports of suspected myocarditis for Comirnaty (Pfizer) 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 269 suspected cases:

  • 161 were classified as likely to be myocarditis (12 were level 1, 48 were level 2 and 101 reports were level 3) 

  • 27 were deemed unlikely to be myocarditis

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

Table 4. Total cases classified as likely to be myocarditis (levels 1-3) following Comirnaty to 10 October 2021
Age (years) All doses Second doses
Total cases Rate* per 100,000 doses Total cases Rate* per 100,000 doses
Male Female Male Female Male Female Male Female
≤19† 32 8 3.4 0.8 20 4 7.5 1.4
20-29 21 12 1.3 0.7 13 9 2.2 1.2
30-39 18 12 0.9 0.5 5 3 0.6 0.3
40-49 17 16 0.8 0.7 10 11 1.0 1.0
50-59 6 9 0.4 0.6 2 2 0.3 0.3
60-69 0 3 0.0 0.7 0 0 0.0 0.0
70+ 0 0 0.0 0.0 0 0 0.0 0.0
Age unknown 2 3 1 0
All ages 96 63 1.2 0.7 51 29 1.6 0.8

*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 12 years. Nineteen cases were in individuals under 18 years of age.

‡Two cases did not specify patient sex and have not been included in the table above.

Most of the patients with myocarditis experienced symptoms within 3 days of vaccination. Less than half required treatment in hospital and of those most were discharged within 4 days.

Our analysis of the likely myocarditis cases suggests they are reported more frequently in teenage boys, particularly 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. We are also working closely with international medicines regulators to share emerging safety information.

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

Comirnaty (Pfizer) vaccine

To 10 October 2021, approximately 18.1 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 and pericarditis and continues to work with international regulators on this safety signal.

Correction: In the 30 September 2021vaccine safety report, the total number of reports of suspected myocarditis and/or pericarditis for Comirnaty (Pfizer) mistakenly included cases reported for Vaxzevria (AstraZeneca). The number of reports should have been 724 rather than 850.

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Weakness, lethargy, decreased appetite and night sweats

Weakness (asthenia), lack of energy or sleepiness (lethargy), decreased appetite, and night sweats (nocturnal hyperhidrosis) were added to the Comirnaty (Pfizer) Product Information in July 2021 following review of clinical trial data submitted to support use of the vaccine in adolescents. Recently, the European Medicines Agency’s Pharmacovigilance Risk Assessment Committee also recommended that these adverse events should be listed as side effects in the European prescribing information for Comirnaty (Pfizer). 

These are temporary symptoms that are known to occasionally occur after vaccination. So far for the Comirnaty (Pfizer) vaccine, we have received approximately 230 reports of asthenia (weakness), 4100 reports of lethargy, 230 reports of decreased appetite and 580 reports of excessive sweating. These effects generally occurred within a day of vaccination when details were given. Lethargy was reported more often after the second vaccine dose.

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

Spikevax (Moderna) vaccine

The Spikevax (Moderna) vaccine is now being rolled out in Australia. To 10 October 2021, approximately 298,000 doses have been given. We have received 217 reports of suspected adverse events associated with the vaccine.

In general, these were expected reactions consistent with what has been reported in the trials and included injection-site reactions, headache, chest pain, dizziness and nausea. We are actively investigating reports of myocarditis and pericarditis with this vaccine (see above).

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).