COVID-19 vaccine weekly safety report - 13-01-2022

Published

13 January 2022

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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. Often, however, 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 1–2 in every 100,000 people who receive Comirnaty (Pfizer) and 2–3 in every 100,000 people who receive Spikevax (Moderna). However, it is more common after the second dose in teenage boys (12 cases per 100,000 Comirnaty doses and 17 cases per 100,000 Spikevax doses) and men under 30 (6 cases per 100,000 Comirnaty doses and 12 cases per 100,000 Spikevax doses).
- To 9 January 2022, the TGA has received 952 reports which have been assessed as likely to be myocarditis from about 28.4 million doses of Comirnaty (Pfizer) and 96 reports which have been assessed as likely to be myocarditis from about 2.1 million doses of Spikevax (Moderna).
Thrombosis with thrombocytopenia syndrome (or TTS) is a very rare but serious side effect of Vaxzevria (AstraZeneca). Our analysis shows it is reported in about 2 in every 100,000 vaccinated people following the first dose. The risk of TTS is much lower after the second dose (0.3 in every 100,000 vaccinated people).
- No new cases of probable TTS were reported in the past week.

Total adverse event reports to 9 January 2022

2.3
Reporting rate per 1000 doses
99659
Total AEFI reports received
44113001
Total doses administered
43752
Total reports for Vaxzevria
52143
Total reports for Comirnaty
3454
Total reports for Spikevax

To 9 January 2022, the total number of adverse event reports received where the brand of the COVID-19 vaccine was not specified was 480.

Reported side effects for COVID-19 vaccines

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.

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.

Vaccine safety in children and adolescents

The TGA is closely monitoring reports in people aged under 18 years. To 9 January 2022, we have received about 3,000 reports after vaccination with Comirnaty (Pfizer) and Spikevax (Moderna). The most commonly reported reactions in 12–17 year olds are:

chest pain
headache
dizziness
nausea
fever.

The Comirnaty (Pfizer) vaccine is now being rolled out to 5–11 year olds in Australia. This follows provisional approval by the TGA and a recommendation by the Australian Technical Advisory Group on Immunisation (ATAGI).

Evidence from clinical trials and real-world experience from overseas indicate that side effects most commonly seen in this age group were mild and temporary similar to the safety profile in older populations. In clinical trials of over 2000 children, most side effects were reported in the first 2 to 3 days after vaccination with the most common being a sore arm (70% of children), headache (25%) and tiredness (25%).

In the US, over 8 million doses of the vaccine have already been given to children aged 5–11 from 3 November to 19 December 2021. A review of active and passive vaccine surveillance data published by the US Centers for Disease Control and Prevention (CDC) found similar safety findings to the clinical trial with most side effects being mild. A survey conducted shortly after vaccination found that about 5% of children missed school (usually only a single day or less) after a first dose and 7% after a second dose.

Reports of more serious effects following vaccination in children in the US were extremely rare with 100 reports from 8.7 million vaccine doses – the most common were fever, vomiting and in some cases seizures.

Importantly, myocarditis was also very rare in this age group, with 11 confirmed reports from over 8 million doses – these were all mild cases.

The TGA is closely monitoring adverse event reports in this age group and will communicate any safety issues if they arise.

More information and frequently asked questions about COVID-19 vaccines in children are available on the National Centre for Immunisation Research and Surveillance website.

Booster doses

The TGA is monitoring the safety of booster vaccine doses in adults. It is not expected that the types of side effects will be different to first and second vaccine doses based on the results of clinical trials, and observations from regulators overseas where more booster doses have been given.

The Comirnaty (Pfizer) and Spikevax (Moderna) vaccines are recommended for use as booster doses for adults in Australia. For people who are immunocompromised, a third dose is given as part of their primary vaccine course. This is not considered to be a ‘booster’. The latest vaccination recommendations are available from ATAGI.

To 9 January 2022, we have received approximately 950 reports of suspected adverse events identified after a third or booster dose. This includes a small number of cases of myocarditis and pericarditis.

The most common adverse events reported to the TGA following a booster dose are swollen lymph nodes (also called lymphadenopathy), headache, fatigue, muscle pain and fever. Swollen lymph nodes are a normal and known side effect of vaccines and occurs when the immune system is stimulated and were seen in the clinical trials. There was more information about this potential side effect in last week's report.

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. As the number of people being vaccinated has increased, so has reporting of fatal events with a temporal association with vaccination. Review of these individual reports and patterns of reporting does not suggest that the vaccines played a role in the vast majority of these deaths.

The TGA closely reviews all adverse events after COVID-19 vaccination where a fatal outcome is reported. Read more about this process in a previous report. Since the beginning of the vaccine rollout to 9 January 2022, about 44.1 million doses of COVID-19 vaccines have been given. The TGA has identified 11 reports of death that were linked to vaccination from 740 reports received and reviewed. The deaths linked to vaccination occurred after the first dose of Vaxzevria (AstraZeneca) – 8 were thrombosis with thrombocytopenia syndrome (TTS) cases, 2 were linked to Guillain-Barre Syndrome (GBS) and one was a case of immune thrombocytopenia (ITP).

AusVaxSafety – a national survey on COVID-19 vaccine safety

AusVaxSafety actively collects responses from Australians about adverse events after they have received a COVID-19 vaccine. It tells us what proportion of people experience an adverse event and what the most common reactions are. It also measures how frequently people go to the doctor or miss work or study because of an adverse event. Reassuringly, survey results largely reflect what was seen in the clinical trials, with injection-site reactions, fatigue, headache, and muscle and joint pain being the most common reactions.

Results are given for everyone who has taken the survey, which is about 5 million Australians so far. Data is presented for each vaccine and for the first, second and third or booster doses. Vaccine safety data is also given for subgroups of the population including:

For more details and results of the survey, go to the AusVaxSafety website.

Comirnaty (Pfizer) mRNA vaccine

To 9 January 2022, about 28.4 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 9 January 2022, about 2.1 million doses of Spikevax (Moderna) have been administered in Australia. The TGA provisionally approved the use of Spikevax (Moderna) as a booster dose on 8 December 2021.

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

Vaxzevria (AstraZeneca) vaccine

To 9 January 2022, about 13.7 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).

Several recent updates have been made to the Vaxzevria (AstraZeneca) PI under section 4.4 Special warnings and precautions for use. These are based on post-market monitoring and include:

An updated warning about neurological events which specifically mentions Guillain-Barré Syndrome (GBS) as a demyelinating disorder.
A new statement under Thrombosis and thrombocytopenia:
“The reporting rates after the second dose are lower compared to after the first dose.”
A new warning for venous thromboembolic events without thrombocytopenia:
“Venous thromboembolic events without accompanying thrombocytopenia, including events of cerebrovascular venous and sinus thrombosis (CVST) have been reported following vaccination with VAXZEVRIA. Although a causal relationship has not been established, these events can be fatal and may require different treatment approaches than TTS. Healthcare professionals should consult applicable guidance.”

Venous thromboembolic events include common clots, such as those that develop in the legs and lungs (deep vein thrombosis and pulmonary embolism), as well as more serious clots which can form in the brain. A link between these clots and vaccination is not clear, except when they occur in people with Thrombosis with Thrombocytopenia syndrome (TTS) linked to the vaccine.

CVST without thrombocytopenia is a rare disorder that has not previously been associated with vaccination. CVST is a rare type of stroke which occurs when a blood clot forms in the brain’s drainage system (the venous sinuses). Some patients with a CVST have also been found to have low platelets (also known as thrombocytopenia). However, cases of CVST without thrombocytopenia have also been reported following vaccination, both in Australia and overseas. As CVST with and without thrombocytopenia may require different medical management, clinicians should seek advice from a specialist haematologist to diagnose and treat these conditions. To 9 January 2022, the TGA had received 45 reports of CVST and other related events without thrombocytopenia in people who have received the Vaxzevria (AstraZeneca) vaccine.

CVST is a serious condition that requires rapid treatment and can be fatal. CVST has also been reported as a complication of COVID-19 disease. In the general population, CVST is more common in women than men (3:1) and the risk of it occurring is slightly higher in women on the oral contraceptive pill, or who are pregnant or just had a baby. People with cancer or a pre-existing clotting disorder also have a slightly higher risk of CVST.

Symptoms of CVST can include severe or persistent headache, blurred vision, vomiting, confusion or seizures. Anyone with these symptoms should seek urgent medical attention.

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

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.

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

For those with suspected pericarditis after a first dose, future dose recommendations depend on test results and the person’s age and sex. Refer to expert Guidance on myocarditis and pericarditis after mRNA COVID-19 vaccines for more information.

What are myocarditis and pericarditis?

Myocarditis is inflammation of the heart, and pericarditis is inflammation of the membrane around the heart. They can occur as rare adverse events after vaccination with the mRNA vaccines Comirnaty (Pfizer) and Spikevax (Moderna).

When do myocarditis and pericarditis occur?

Cases typically occur within 10 days, with symptom onset often within 5 days of vaccination. Some published evidence found pericarditis symptoms may occur later, commonly 2-3 weeks after vaccination. Our analysis indicates that most of the patients with likely myocarditis experienced symptoms within 3 days of vaccination.

How common are myocarditis and pericarditis?

In some countries, higher rates of myocarditis and pericarditis have been reported with Spikevax (Moderna) than with Comirnaty (Pfizer). In Australia, we are seeing slightly higher (40%) overall estimated rates of myocarditis for Spikevax – 2.1 cases per 100,000 Spikevax doses versus 1.5 cases per 100,000 Comirnaty doses. This difference is smaller than that reported overseas, including in the UK and Canada.

Pericarditis has been reported in 2–3 in every 100,000 people who receive an mRNA vaccine. Preliminary analysis of Australian data indicates pericarditis following vaccination occurs most commonly in people aged under 50 years, with a trend to a higher rate in the 18-39 year old group. It remains a rare adverse event.

Who is at risk of these heart problems?

Myocarditis is more commonly reported after the second dose in teenage boys (12 cases per 100,000 Comirnaty doses and 17 cases per 100,000 Spikevax doses) and men under 30 (6 cases per 100,000 Comirnaty doses and 12 cases per 100,000 Spikevax doses). However, even in this population it remains rare.

Emerging Australian and international data indicate that pericarditis is more common in people under 50 years of age than in older people.

A European review of myocarditis and pericarditis data in teenage boys and young men (12-29 years old) found for Comirnaty, there were 2–6 extra cases of myocarditis per 100,000 vaccinated individuals compared to unvaccinated individuals. For Spikevax, there were 13–19 extra cases of myocarditis per 100,000 vaccinated individuals compared to unvaccinated individuals. The Australian data does not show as large a difference in incidence of myocarditis as this review between Comirnaty (Pfizer) and Spikevax (Moderna). In Australia the rates of pericarditis are similar between the mRNA vaccines.

How serious is myocarditis?

Myocarditis is often mild, and cases usually resolve after a few days with treatment and rest. Some cases are more serious need to be treated in hospital. Our analysis has found about half of the patients with suspected myocarditis were admitted to hospital. Five people with confirmed myocarditis were treated in intensive care. This represents about 1% of all confirmed myocarditis cases. Most patients admitted to hospital were discharged within 4 days.

What myocarditis and pericarditis symptoms should I look out for?

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 levels 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.

What does the TGA know about Australian myocarditis and pericarditis cases?

Reports received by the TGA of suspected myocarditis and pericarditis for the 2 mRNA vaccines are provided in Table 1. We have reviewed these reports against an internationally accepted criteria to classify the likelihood of myocarditis. This assessment does not determine whether cases have been caused by vaccination. Tables 2 and 3 present the rates of myocarditis and pericarditis.

We have received a small number of reports of myocarditis and pericarditis after a third or booster dose. To 9 January 2022, we have received 4 reports of likely myocarditis and 10 reports of likely pericarditis where the third or booster dose was Comirnaty (Pfizer). There have also been 2 reports of likely myocarditis and 2 reports of likely pericarditis where the third or booster dose was Spikevax (Moderna).

Table 1. Reports of suspected myocarditis and pericarditis received by the TGA to 9 January 2022
		Comirnaty (Pfizer) (28.4 million doses given)		Spikevax (Moderna) (2.1 million doses given)
		All cases	Cases in adolescents (12–17 years)	All cases	Cases in adolescents (12–17 years)
Suspected myocarditis cases*		952	178	96	23
Likely myocarditis†‡	Level 1	37	7	0	0
	Level 2	315	99	34	13
	Level 3	71	12	10	3
Unlikely myocarditis		203	18	18	2
Insufficient information		326	42	34	5
Suspected pericarditis cases		2,015	145	168	10
Likely pericarditis£		752	61	53	2

*Cases reporting both myocarditis and pericarditis are included in suspected myocarditis cases.

‡ Cases classified as level 1 are confirmed to be myocarditis based on strong clinical evidence including the patient’s symptoms, and results of tests and imaging indicating a diagnosis of myocarditis. Level 2 cases are probably myocarditis based on a combination of symptoms and routine tests for heart conditions. Level 3 cases are possibly myocarditis based on symptoms and a doctor’s report that myocarditis is the most likely diagnosis in the absence of medical tests and investigations. For all cases of suspected myocarditis, where possible, other known causes of the patient’s symptoms or test results are ruled out before cases are classified.

†The youngest case classified as ‘likely myocarditis’ to date was 12 years old.

£ Classification of likely pericarditis is based on the patient’s symptoms and test results and the absence of other known causes of pericarditis.

Rates of myocarditis by age, sex and dose are given for Comirnaty (Pfizer) and Spikevax (Moderna) in Table 2. The estimated reporting rates in Australia appear similar to overseas rates. The rates for Spikevax (Moderna) are less certain due to low numbers of cases overall. Rates of pericarditis by age are given for Comirnaty (Pfizer) and Spikevax (Moderna) in Table 3.

Table 2. Rates of likely myocarditis cases following the mRNA vaccines 1.Comirnaty (Pfizer)
Age (years)	All doses		Second doses
	Rate* per 100,000 doses		Rate* per 100,000 doses
	Male	Female	Male	Female
12-17	7.3	1.5	11.8	2.5
18-29	4.0	1.3	6.2	1.9
30-39	1.7	0.7	1.6	0.5
40-49	0.8	0.6	1.2	0.8
50-59	0.4	0.3	0.1	0.4
60-69	0.1	0.2	0.0	0.3
70+	0	0.1	0	0
All ages*	2.2	0.8	3.3	1.0

2. Spikevax (Moderna)
Age (years)	All doses		Second doses
	Rate* per 100,000 doses		Rate* per 100,000 doses
	Male	Female	Male	Female
12-17	9.1	1.4	16.5	1.5
18-29	6.5	0.6	11.6	0.0
30-39	4.1	0.7	7.3	0.0
40-49	1.2	0.7	0.0	0.0
50-59	0.7	1.4	0.0	0.0
60-69	0.0	0.0	0.0	0.0
70+	0.0	0.0	0.0	0.0
All ages*	4.7	0.9	7.4	0.5

*The rate includes cases of myocarditis that occurred after vaccination but may not be vaccine related.

Table 3. Rates of likely pericarditis cases following the mRNA vaccines
Age (years)	Rate* per 100,000 doses
	Comirnaty (Pfizer)	Spikevax (Moderna)
12-17	2.3	0.7
18-29	3.4	5.1
30-39	3.9	5.8
40-49	2.4	2.5
50-59	1.4	0.7
60-69	0.7	0.0
70+	0.4	0.0
All ages*	2.6	2.6

*The rate includes cases of pericarditis that occurred after vaccination but may not be vaccine related.

We continue to monitor Australian reports on myocarditis and pericarditis 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

What is TTS?

Thrombosis with thrombocytopenia syndrome (TTS) is a rare but serious adverse event linked to the Vaxzevria (AstraZeneca) vaccine. People with TTS have blood clots and low blood platelets.

When does TTS occur?

TTS symptoms usually start between 4–30 days after vaccination. In Australia, cases most often occurred about 2 weeks after vaccination.

How common is TTS?

TTS is a rare adverse event. In Australia, it occurs in about 2 out of every 100,000 people after a first dose. The risk of TTS after a second vaccine dose appears to be much lower and is estimated to be 0.3 out of every 100,000 people after a second dose.

Who is at risk of TTS?

Younger women seem to be slightly more likely to have serious outcomes from TTS as they more often experience clots in unusual locations, such as the brain or abdomen. These cases are classified as ‘Tier 1’. People under 60 years are more likely to be classified as Tier 1 and/or require treatment in intensive care.

How serious is TTS?

TTS can be a serious illness and most people require treatment in hospital. Occasionally, TTS is fatal. In Australia, the risk of dying from TTS after vaccination is about one in a million (people receiving a first dose). Of the 170 people who developed TTS, 8 of them died – 6 of these were women.

What TTS symptoms should I look out for?

It is important for people with symptoms of TTS to get medical attention early as this may help to prevent more serious complications. 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.

While TTS is very rare, some people may have concerns that they wish to 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.

Where can I find more information about TTS?

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.

What does the TGA know about Australian TTS cases?

From about 13.7 million vaccine doses, there have been 170 cases of TTS. Of these, 147 (83 confirmed, 64 probable) related to a first dose of Vaxzevria (AstraZeneca) and 23 to a second dose (5 confirmed, 18 probable). No new cases were reported this week (see Table 4).

Table 4: Newly confirmed and probable TTS cases for 7-13 January 2022‡
New confirmed TTS	New probable TTS
No cases	No cases

‡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.

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 after a first dose are classified as Tier 1 (Table 5). Cases reported after a second vaccine dose are much less likely to be classified as Tier 1 with most people having clots in common locations, such as the lungs or legs. The majority of these cases occurred in people over the age of 60 years old.

Table 5: Australian TTS cases to date by age and CDC classification A. First dose cases
Age	Reported cases (6.9 million doses given)	Tier 1 CDC classification†	Reports per 100,000 doses‡
<30 years	8	2	2.0 (<50 years)
30-39	5	4
40-49	11	6
50-59	33	18	3.0
60-69	37	11	1.8
70-79	37	10	2.2
80+	16	4	1.9
All ages	147 (74 men, 73 women)	55 (18 men, 37 women)	2.1

B. Second dose cases
Age	Reported cases (6.7 million doses given)	Tier 1 CDC classification†	Reports per 100,000 doses‡
<30 years	0	0	0 (<50 years)
30-39	0	0
40-49	0	0
50-59	3	1	0.4 (≥50 years)
60-69	8	1
70-79	9	1
80+	3	0
All ages	23 (15 men, 8 women)	3 (2 men, 1 woman)	0.3

‡ Rates of TTS are calculated as of 30 December 2021 to account for the time to onset of TTS. These rates are estimates of risk based on small numbers of cases so far. Aggregated rates are given for some age ranges where the number of cases for a 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).

Table 6: Time to onset, treatment and outcomes for TTS cases*
Vaccine dose	Median time to onset/ diagnosis	Treated in ICU at any point	Currently in ICU	Outcome†
				Discharged	In hospital	Fatal
First	13 days (1-94)	47	0	137	1	8
Second	12 days (2-69)	2	0	23	0	0

*Data is based on the most recent medical information available to the TGA for first and second dose TTS cases.

†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

What is GBS?

GBS is a rare but sometimes serious immune disorder affecting the nerves and can result in pain, numbness, muscle weakness and difficulty walking.

When does GBS occur?

GBS can occur when the immune system is activated and has been associated with infections, including COVID-19, and vaccines. GBS usually occurs days or weeks after an infection or vaccination. However, sometimes a trigger for GBS cannot be identified. The expected time period for onset of GBS symptoms is 2–42 days after vaccination.

How common is GBS?

GBS following vaccination is rare. In Australia, it has been reported in about one in every 100,000 people following the Vaxzevria (AstraZeneca) vaccine.

To 9 January 2022, the TGA has received 170 reports of suspected GBS occurring after vaccination with Vaxzevria (AstraZeneca). It is expected that some of these cases may not be related to vaccination, as GBS can occur after common viral infections and some types of gastroenteritis. In addition, numbers may fluctuate as duplicate cases are identified and processed.

Who is at risk from GBS?

Emerging evidence suggests that GBS may be a rare adverse event associated with Vaxzevria (AstraZeneca). There are currently no identified risk factors for GBS. However, in the general population it is more common in people aged over 60 years.

How serious is GBS?

GBS is a serious condition that can occasionally lead to death. While many cases of GBS resolve within months, recovery in some people can take years. There have been two fatal cases of GBS linked to the Vaxzevria (AstraZeneca) vaccine in Australia. However, there was some uncertainty around this link GBS occurs in people who have not received a vaccine and sometimes there is no obvious trigger identified.

What GBS symptoms should I look out for?

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, pain 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.

What is the TGA doing about GBS cases?

The benefits of Vaxzevria (AstraZeneca) continue to outweigh the risks. Health professionals should be aware of the possible signs and symptoms of GBS in people who have been vaccinated to ensure correct diagnosis and so that treatment can be started early.

There is growing evidence of a possible link between GBS and Vaxzevria (AstraZeneca) following rigorous investigations of safety data by the TGA and other international regulators. This is reflected in recent updates to the Vaxzevria (AstraZeneca) Product Information.

Immune thrombocytopenia (ITP)

What is ITP?

ITP is a rare immune reaction that occurs when platelets, which help blood to clot, are mistakenly destroyed.

When does ITP occur?

It is very rare after COVID-19 vaccination. In Australia, ITP has been reported in less than one in every 100,000 people following the Vaxzevria (AstraZeneca) vaccine.

To 9 January 2022, 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 the TGA.

Who is at risk of ITP?

Currently, no risk factors have been identified that make a person more susceptible to developing ITP following COVID-19 vaccination.

How serious is ITP?

In many cases ITP is mild with up to a third of people having no symptoms at all, or only minor bruising. However, about 5% develop severe bleeding. In a very small number of people it can be fatal.

In Australia, there has been one report of a fatal case of ITP linked to vaccination with Vaxzevria (AstraZeneca). Following an investigation by the TGA, the Product Information has been updated to include a warning about ITP. Other suspected cases of ITP have not been definitively linked to vaccination.

What ITP symptoms should I look out for?

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.