COVID-19 vaccine weekly safety report - 28-10-2021

Published

28 October 2021

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

The TGA closely monitors reports of suspected side effects (also known as adverse events) to the COVID-19 vaccines. This is the most intense safety monitoring ever conducted in Australia.

We encourage people to report suspected side effects, even if there’s only a very small chance a vaccine was the cause. This provides valuable data that helps us identify trends or spikes that might reveal potential safety issues, but often these events are not caused by the vaccines. Learn more about causality and our COVID-19 vaccine safety monitoring and reporting activities.

Report a suspected side effect.

Summary

Vaccination against COVID-19 is the most effective way to reduce deaths and severe illness from infection. The protective benefits of vaccination continue to far outweigh the potential risks.
Like all medicines, COVID-19 vaccines may cause some side effects. The most frequently reported include injection-site reactions (such as a sore arm) and more general symptoms, like headache, muscle pain, fever and chills. This reflects what was seen in the clinical trials.
We are carefully monitoring and reviewing reports of:
- myocarditis and pericarditis following mRNA vaccines, particularly in younger age groups
- thrombosis with thrombocytopenia syndrome (TTS) following Vaxzevria (AstraZeneca)
- Guillain-Barre Syndrome (GBS) following Vaxzevria (AstraZeneca)
- immune thrombocytopenia (ITP) following Vaxzevria (AstraZeneca)
Myocarditis is a known but very rare side effect of Comirnaty (Pfizer) and Spikevax (Moderna). It is usually temporary with most people getting better within a few days. Myocarditis is reported in approximately 1 in of every 100,000 people who receive Comirnaty (Pfizer), although it is more common in teenage boys after the second dose (6.7 cases per 100,000 doses).
- To 24 October, the TGA has received 235 reports which have been assessed as likely to be myocarditis from approximately 21 million doses of Comirnaty (Pfizer). This is an increase of 60 reports since last week.
Thrombosis with thrombocytopenia syndrome (or TTS) is a very rare but serious side effect of Vaxzevria (AstraZeneca). Our analysis shows it occurs in approximately 2 in every 100,000 people following vaccination, although the risk appears higher in people under 60 years. The risk is much lower after the second dose.
- One new case of probable TTS was reported this week, taking the total to 157 cases from approximately 12.9 million doses of Vaxzevria (AstraZeneca).

Total adverse event reports to 24 October 2021

2.2
Reporting rate per 1000 doses
74380
Total AEFI reports received
34364950
Total doses administered
39496
Total reports for Vaxzevria
33878
Total reports for Comirnaty
670
Total reports for Spikevax

To 24 October 2021, the total number of adverse event reports received where the brand of the COVID-19 vaccine was not specified was 397.

Reported side effects for COVID-19 vaccines

Learn more about how the TGA identifies and responds to safety issues.

The most frequently reported side effects suspected to be associated with the vaccines include injection-site reactions, such as a sore arm, headache, muscle and joint pain, fever and chills.

The TGA is closely monitoring reports in people aged under 18 years as vaccination continues in this age group. To 24 October 2021, we have received 1255 reports after vaccination with Comirnaty (Pfizer) and Spikevax (Moderna). The most commonly reported reactions are:

dizziness
nausea
chest pain
fainting (syncope) and feeling faint (pre-syncope)
headache.

For more information on side effects reported in adolescents, check out the AusVaxSafety survey results for those aged under 20 years old.

Anyone can report a suspected side effect, either:

directly to the TGA
through a health professional
by calling the NPS MedicineWise Adverse Medicine Events phone line for consumers.

You can report anonymously.

Learn more about how to report a suspected side effect to a COVID-19 vaccine.

Side effects reported for Aboriginal and Torres Strait Islander people

Since the beginning of the vaccine rollout to 24 October 2021, the TGA has received 796 adverse event reports for Aboriginal and Torres Strait Islander people. During this time approximately 629,000 vaccine doses have been given in this population, giving a reporting rate of 1.3 suspected adverse events per 1000 doses.

The side effects reported for Aboriginal and Torres Strait Islanders are similar to the total population with the most common being headache, muscle pain, fever, fatigue and nausea.

Further information on adverse event reports in Aboriginal and Torres Strait Islander people is published in the ongoing AusVaxSafety survey.

Reports of death in people who have been vaccinated

Large scale vaccination means that some people will experience a new illness or die within a few days or weeks of vaccination. These events are often coincidental, rather than being caused by the vaccine.

The TGA reviews all deaths reported in people who have been recently vaccinated. As the number of people being vaccinated has increased, so has reporting of fatal events with a coincidental association with vaccination. Our review of individual reports and patterns of reporting does not suggest that the vaccines played a role in the vast majority of these deaths.

Since the beginning of the vaccine rollout to 24 October 2021, approximately 34.4 million doses of COVID-19 vaccines have been administered. The TGA has found 9 reports of death that were linked to immunisation from 629 reports received and reviewed. The overwhelming majority of deaths reported 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).

Comirnaty (Pfizer) mRNA vaccine

To 24 October 2021, approximately 21 million doses of Comirnaty (Pfizer) have been administered in Australia.

The TGA is actively investigating reports of myocarditis (inflammation of the heart) and/or pericarditis (inflammation of the membrane around the heart) associated with mRNA vaccines. We continue to work with international regulators on this safety signal (see below).

Up-to-date information for Comirnaty (Pfizer), including details of potential side effects , can be found in the Consumer Medicine Information (for consumers) and Product Information (for health professionals).

Spikevax (Moderna) mRNA vaccine

To 24 October 2021, approximately 500,000 doses of Spikevax (Moderna) have been administered in Australia.

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

Vaxzevria (AstraZeneca) vaccine

To 24 October 2021, approximately 12.9 million doses of Vaxzevria (AstraZeneca) have been administered in Australia.

The TGA is closely monitoring rare reports of blood clots with low blood platelets (also called thrombosis with thrombocytopenia syndrome or TTS) linked to this vaccine. We are also monitoring reports of immune thrombocytopenia (ITP) and Guillain-Barre Syndrome (GBS). See below for more details.

The prescribing information for Vaxzevria (AstraZeneca) has recently been updated to include warnings about ITP and GBS. This is a cautious approach, as a clear relationship between GBS and Vaxzevria (AstraZeneca) has not been established, and vaccine-related ITP is very rare and frequently occurs due to other causes.

Up-to-date information, including details of these and other potential side effects 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 may occur after vaccination with the mRNA vaccines Comirnaty (Pfizer) and Spikevax (Moderna). Cases typically occur within 10 days, and usually resolve after a few days following treatment and rest. In Australia, myocarditis is reported in approximately 1 out of every 100,000 people after receiving the Comirnaty vaccine. While it is more commonly reported in young men and teenage boys after the second dose (6.7 cases in 100,000 people) it remains rare.

Myocarditis is seen much more commonly in people who become infected with COVID-19 than in people who are vaccinated. 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.

Details of Australian cases to 24 October 2021

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.

In the UK, higher rates of myocarditis and pericarditis have been reported with Spikevax (Moderna) than with Comirnaty (Pfizer). The TGA is looking closely at Australian reports, however because use of Spikevax is still relatively low, we are not able to calculate reliable reporting rates for the population yet.

From 21 million Comirnaty (Pfizer) doses given, we have received 404 reports of suspected myocarditis alone or in combination with pericarditis, with 67 of these reports in adolescents (12- 17-years-old). We have also received 971 reports of suspected pericarditis alone, with 65 of these reports in adolescents. In the same period for 500,000 Spikevax doses given, we have received 9 reports of suspected myocarditis and 33 reports of suspected pericarditis. Three of the pericarditis cases were in children – one 12 and two 16-year-old boys. 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 received limited reports for the Spikevax (Moderna) vaccine, our analysis focuses on data for the Comirnaty (Pfizer) vaccine. We have reviewed reports of myocarditis for Comirnaty (Pfizer) against an internationally accepted criteria to classify the likelihood of 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 404 suspected cases:

235 were classified as likely to be myocarditis (25 were level 1, 153 were level 2 and 57 reports were level 3)
75 were deemed unlikely to be myocarditis
97 could not be classified because they did not contain enough information.

Table 1. Total cases classified as likely to be myocarditis (levels 1-3) following Comirnaty to 24 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
≤17†	43	8	4.6	0.9	25	5	6.7	1.4
18-29	63	21	2.7	0.8	43	14	3.6	1.1
30-39	27	14	1.2	0.5	13	4	1.3	0.3
40-49	15	19	0.6	0.8	12	13	1.1	1.1
50-59	6	8	0.4	0.5	1	4	0.1	0.5
60-69	0	2	0.0	0.4	0	0	0.0	0.0
70+	0	1	0.0	0.2	0	1	0.0	0.0
Age unknown	2	2			1	0
All ages‡	156	75	1.7	0.7	95	41	2.2	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 old.

‡Four 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. Around half were admitted to hospital for treatment 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 (6.7 cases per 100,000 doses) compared to the rest of the population after a first or second dose (1.0 per 100,000 doses). 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).

Thrombosis with thrombocytopenia syndrome (TTS)

TTS is a rare but serious adverse event linked to the Vaxzevria (AstraZeneca) vaccine. It is characterised by blood clots and low blood platelets which develop within a few days or weeks after vaccination. In Australia, it occurs in approximately 2 out of every 100,000 vaccinated people.

p dir="ltr">Early detection of TTS may help to prevent more serious complications developing. Guidance for health professionals is now available(link is external) 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(link is external) 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.

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, there have been 157 cases of TTS assessed as related to Vaxzevria (AstraZeneca) from approximately 12.9 million vaccine doses. 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.

One new case of probable TTS was reported this week. This takes the total number of Australian reports assessed as TTS following Vaxzevria (AstraZeneca) to 157 cases (86 confirmed, 71 probable) from approximately 12.9 million vaccine doses.

Table 2: Newly confirmed and probable TTS cases for the week of 15-21 October 2021‡
New confirmed TTS	New probable TTS
No new cases	One new case: 78-year-old woman from Victoria

‡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. Cases may be reclassified as further information becomes available.

To date, 19 cases of TTS have occurred after the second dose. Thirteen cases have been assessed as probable TTS, with 6 cases assessed as confirmed TTS. All cases have occurred in individuals older than 50 years, with 16 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. Our preliminary analysis is consistent with overseas investigations which have shown that the risk of TTS after the second dose is extremely low (less than one case per 100,000 second doses administered).

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 (Table 3). Tier 1 cases involve clots in an unusual location, such as the brain or abdomen. 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.

Table 3: Total confirmed and probable TTS cases to date by age and CDC classification
Age	Total cases	Tier 1 CDC classification†	Reports per 100,000 doses‡
<30 years	8	2	2.0 (<50 years)
30-39	5	4
40-49	10	6
50-59	36	19	3.0
60-69	37	11	1.6
70-79	42	11	2.1
80+	19	4	1.8
All ages	157 (79 men, 78 women)	57 (20 men, 37 women)	2.0

‡ Rates of TTS are calculated based on first doses of the Vaxzevria (AstraZeneca) vaccine as of 14 October 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 of Tier 1 is defined as 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).

Cases have most often occurred about 2 weeks after vaccination, although the time to onset (or diagnosis) has ranged from 1-83 days (Table 4).

Table 4: Time to onset, treatment and outcomes for TTS cases*
Time to onset/ diagnosis (days)	Median (range)	13 (1-83)
Treated in ICU	At any point	47
	Currently	0
Outcome†	Discharged	140
	In hospital	8
	Fatal	8

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

†As previously reported, one patient died from unrelated medical conditions while being treated for TTS. The outcome for this patient is not included in this table.

Guillain-Barre Syndrome (GBS)

In Australia, GBS has been reported in about one in every 100,000 people following the Vaxzevria (AstraZeneca) vaccine. It is a rare but sometimes serious immune disorder affecting the nerves and can result in pain, numbness, muscle weakness and difficulty walking. GBS can occur when the immune system is activated and has been associated with COVID-19 and other infections.

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, warning statements about GBS have been added to the Vaxzevria (AstraZeneca) Product Information in response to rare cases following vaccination.

To 24 October 2021, the TGA has received 138 reports of suspected GBS occurring after vaccination with Vaxzevria (AstraZeneca). It is expected that some suspected cases may not be 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. Symptoms tend to affect both sides of the body.

Immune thrombocytopenia (ITP)

In Australia, ITP has been reported in less than one in every 100,000 people following the Vaxzevria (AstraZeneca) vaccine. It is a rare immune reaction that can occur after a viral infection or vaccination when platelets, which help blood to clot, are mistakenly destroyed.

Following an investigation by the TGA, the Vaxzevria Product Information has been updated to include a warning about ITP. Apart from one fatal case that was assessed by an expert Vaccine Safety Investigation Group as being likely to be vaccine related, other suspected cases of ITP have not been definitively linked to vaccination.

We continue to monitor reports of suspected ITP. To 24 October 2021, the TGA has received 86 reports of suspected ITP following vaccination with Vaxzevria (AstraZeneca). 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.

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.