Covid vaccine safety report - 15-12-2022

The most frequently reported side effects suspected to be associated with the vaccines include headache, muscle and joint pain, fever, chills and nausea. Skin reactions at the site of the injection are also common and can include pain, swelling, redness and an itchy rash. These are recognised side effects of vaccination and are usually transient and mild.

Vaccine safety in children and adolescents

The most up-to-date vaccine recommendations for children are available from the Australian Technical Advisory Group on Immunisation (ATAGI).

The TGA is closely monitoring adverse event reports in people aged under 18 years. The rate of reports has stabilised with only a small number now being received each week.

To 11 December 2022, we have received about 4,300 reports from approximately 3.7 million doses of Comirnaty (Pfizer) and Spikevax (Moderna) in 12-17 year olds. The most commonly reported reactions are chest pain, headache, dizziness, nausea and fever.

The TGA is also closely monitoring adverse event reports in 5-11 year olds. To 11 December 2022, we have received about 1,660 reports from approximately 2.3 million Comirnaty (Pfizer) and Spikevax (Moderna) doses administered in this age group. The most common reactions reported included chest pain, vomiting, fever, headache and abdominal pain. We have received 39 reports of suspected myocarditis and/or pericarditis in this age group. Following review of the reports, 4 were likely to represent myocarditis and another 7 reports were likely to represent pericarditis.

Survey data from AusVaxSafety show that:

• children and adults are more likely to experience side effects after a second COVID-19 vaccine dose, but most reactions are mild and temporary.
• children aged 5-11 years report fewer side effects than older Australians following a second dose.

These observations are consistent with what was reported in the clinical trials and from overseas experiences.

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

Safety monitoring in the under 5s

ATAGI recommends vaccination for children aged 6 months to less than 5 years who are at increased risk of severe COVID-19. This includes children with severe immunocompromise, complex or multiple health conditions, or disability with significant or complex health needs.

The TGA will be closely monitoring reports of adverse events in younger children. AusVaxSafety has also started monitoring vaccine safety through a short online survey to parents or carers after their child has been vaccinated.

The paediatric Spikevax (Moderna) vaccine has been tested in around 5,500 children aged 6 months to under 5 years in the KidCOVE clinical trial. This study found the safety and efficacy of the vaccine was similar to that seen in adults. Most adverse effects were mild-moderate, lasted 1-2 days, and were generally reported after the second dose. Common reactions included irritability and crying, redness and swelling at the injection site, tiredness, fever, muscle pain and swelling or tenderness of lymph nodes near the injection site. Fever was more common in this age group compared to older children and adults, and children who had previously had SARS-CoV-2 infection were more likely to have side effects after vaccination.

In the US, where over a million doses of the paediatric mRNA vaccines have already been given, analysis of vaccine surveillance data by the Centers for Disease Control and Prevention reveals that most adverse events are mild-moderate. Serious events were very rare and no unexpected safety concerns were detected. This is consistent with findings from the clinical trials.

Booster doses

The most up-to-date vaccine recommendations for booster doses are available from ATAGI.

The TGA is monitoring the safety of booster vaccine doses in adults. A booster dose is an additional vaccine dose given after the primary vaccine course. In people who have recently had COVID-19, a 3-month interval is recommended before having their next scheduled dose.

In this report, we refer to a booster dose as either a third or fourth dose. To 11 December 2022, approximately 14.3 million people have received boosters in Australia. This includes 5.3 million people who have received a fourth dose. We have received approximately 9,930 reports of suspected adverse events identified as occurring after a booster dose.

Adverse event reports for booster doses include a small number of myocarditis and pericarditis cases. This is a recognised risk with the Comirnaty (Pfizer) and Spikevax (Moderna) vaccines and we are closely monitoring these events. So far, reports of myocarditis after a booster dose are very rare, occurring in less than 1 in every 100,000 vaccinated people.

The most common adverse events reported to the TGA following a booster dose are headache, swollen lymph nodes (also called lymphadenopathy), chest pain, muscle pain and fever. Swollen lymph nodes are a normal and known side effect of vaccines. They occur when the immune system is stimulated and were seen in the COVID-19 vaccine clinical trials. More detail about this potential side effect is given in a previous vaccine safety report on the 6 January 2022.

Reports of death in people who have been vaccinated

Vaccines can lead to death in extremely rare instances. However, most deaths that occur after vaccination are not caused by the vaccine. In large populations in which a new vaccine is given, there are people with underlying diseases who may die from these diseases. When a vaccine is given in that same population, the link between the vaccine and death is usually coincidental - not caused by the vaccine. These deaths are carefully reviewed for whether vaccines could be the cause and for the vast majority that is not the case.

The TGA closely reviews all deaths reported in the days and weeks after COVID-19 vaccination. Read more about this process in a previous report. Since the beginning of the vaccine rollout to 11 December 2022, about 64.4 million doses of COVID-19 vaccines have been given in Australia. The TGA has identified 14 reports where the cause of death was linked to vaccination from 952 reports received and reviewed. As previously reported, 13 of these deaths occurred after the first dose of Vaxzevria (AstraZeneca) - 8 were associated with thrombosis with thrombocytopenia syndrome (TTS) cases, 2 were linked to Guillain-Barre syndrome (GBS), 2 related to very rare conditions involving the nervous system, and one was a case of immune thrombocytopenia (ITP). One of the deaths occurred after a booster dose of the Spikevax vaccine and was related to myocarditis. Details have been published in a previous report.

The 14 deaths likely to be related to vaccination occurred in people aged 21-81 years old. There have been no deaths in children or adolescents determined to be linked to COVID-19 vaccination.

AusVaxSafety - a national survey on COVID-19 vaccine safety

AusVaxSafety has collected responses from over 6 million Australians about adverse events after they have received a COVID-19 vaccine. An analysis of survey data affirms the safety of the Comirnaty (Pfizer) and Vaxzevria (AstraZeneca) vaccines. Results largely reflect what was seen in the clinical trials, with injection-site pain, fatigue, headache, and muscle pain being the most common reactions. Most reactions were short-lived and just under 1% of respondents sort medical advice because of an adverse reaction in the first 3 days after vaccination.

On the AusVaxSafety website, survey results are presented for each COVID-19 vaccine:

• Comirnaty (Pfizer) adult formulation and paediatric formulation (5-11 years)
• Spikevax (Moderna)
• Vaxzevria (AstraZeneca)
• Nuvaxovid (Novavax)

For each vaccine, survey results are given for different age groups and different populations, such as Aboriginal and Torres Strait Islander people, those affected by cancer or who have received a transplant, and pregnant women.

Comirnaty (Pfizer) mRNA vaccine

The Comirnaty (Pfizer) vaccine is provisionally approved for adults and children aged 5 years and over. To 11 December 2022, about 44.4 million doses 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).

A bivalent vaccine from Pfizer has been provisionally approved as a booster dose in adults. In an ongoing clinical trial, it was found to trigger a modest improvement in the immune response to both the BA.1 Omicron variant and the ancestral COVID-19 strain.

ATAGI recommends the bivalent vaccine as an alternative to any of the original or bivalent Pfizer or Moderna mRNA vaccines. It should be given at least 3 months after a previous COVID-19 vaccine dose or infection. More detail about this vaccine is available from ATAGI.

Spikevax (Moderna) mRNA vaccines

The original Spikevax vaccine is provisionally approved for adults and children aged 6 years and over. To 11 December 2022, about 5.4 million doses have been administered in Australia. A paediatric formulation is available for children aged from 6 months to 5 years (or less than 6 years).

A Spikevax bivalent vaccine is provisionally approved for use as a booster dose in adults. This vaccine is designed to trigger an immune response to the original COVID-19 virus and to the BA.1 Omicron variant. It should be given at least 3 months after the previous vaccine dose according to the latest ATAGI guidelines. FAQs about the bivalent vaccine are answered on the National Centre for Immunisation Research and Surveillance website.

The TGA is actively investigating reports of myocarditis (inflammation of the heart muscle) 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).

Nuvaxovid (Novavax) vaccine

The Nuvaxovid (Novavax) vaccine is provisionally approved for adults. To 11 December 2022, about 234,300 doses of Nuvaxovid (Novavax) have been administered in Australia.

The TGA has received a small number of reports of suspected myocarditis and/or pericarditis in people who have received the Nuvaxovid (Novavax) vaccine. After assessing these against a set of internationally accepted criteria, 8 cases* were likely to represent myocarditis and 30 were likely to represent pericarditis.

_{* The total number of reports can fluctuate slightly over time as duplicate reports may be identified and deleted and cases may be reclassified after receiving more information.}

Vaxzevria (AstraZeneca) vaccine

The Vaxzevria (AstraZeneca) vaccine is provisionally approved for adults. To 11 December 2022, about 13.8 million doses of Vaxzevria (AstraZeneca) have been administered in Australia. However, since the end of 2021 very few doses are being used.

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, immune thrombocytopenia (ITP) and Guillain-Barre Syndrome (GBS). These are rare but serious side effects, with TTS reported in about 2 in every 100,000 people after receiving Vaxzevria (AstraZeneca) and ITP and GBS reported in about one in every 100,000 people. Detailed information of our analysis of these adverse effects is available in a previous vaccine safety report.

With only limited use of the Vaxzevria (AstraZeneca) vaccine now in Australia, we have not received any new reports of confirmed or probable TTS this year. The total number of TTS cases reported in Australia is 173. Of these, 149 (83 confirmed, 66 probable) were related to a first dose of Vaxzevria (AstraZeneca) and 24 (5 confirmed, 19 probable) to a second dose. There has been no change in the reporting rates for ITP, GBS or TTS this year but we continue to monitor for reports to identify new information about these risks.

Myocarditis and pericarditis with mRNA vaccines

ATAGI continues to emphasise that the protective benefits of the mRNA vaccines far outweigh the rare risk of these side effects.

ATAGI has advised that people who have had suspected vaccine-related myocarditis or pericarditis should defer further doses of an mRNA COVID-19 vaccine until at least 6 weeks after their symptoms have resolved. They should also discuss future vaccine doses with their treating doctor. Refer to Expert Guidance on myocarditis and pericarditis after mRNA COVID-19 vaccines for more detail about revaccination.

What are myocarditis and pericarditis?

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

Myocarditis and pericarditis are seen in the general population from a variety of causes, including after COVID-19 disease. Not all cases that occur after vaccination are necessarily caused by the vaccine.

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.

Who is at risk of these heart problems?

Myocarditis can occur in males and females but is more commonly reported after the second dose in boys aged 12-17 years (13 cases per 100,000 Comirnaty doses and 24 cases per 100,000 Spikevax doses) and men under 30 (9 cases per 100,000 Comirnaty doses and 20 cases per 100,000 Spikevax doses). However, even in this population it remains rare.

Pericarditis is reported in about 2 in every 100,000 people who receive an mRNA vaccine. It is reported more often after the Nuvaxovid (Novavax) vaccine, with about 13 reports for every 100,000 doses administered, most commonly in males aged 18-49 years old. The pericarditis rate for Nuvaxovid is less certain than for Comirnaty and Spikevax due to the low numbers of Nuvaxovid vaccine doses given.

Do myocarditis and pericarditis occur after a booster dose?

Myocarditis and pericarditis can occur after a booster dose. It is rare but can sometimes be serious. Australian and international data indicate that myocarditis and pericarditis are reported less commonly after a booster dose than after a second dose. The rate of reporting of myocarditis and pericarditis is less than 1 in every 100,000 people after a booster dose.

To 11 December 2022, from approximately 14.3 million people who have received booster doses, we have received 64 reports of likely myocarditis and 116 reports of likely pericarditis for Comirnaty (Pfizer) and 30 reports of likely myocarditis and 32 reports of likely pericarditis for Spikevax (Moderna). The median age of affected individuals was 34 years old.

How serious are myocarditis and pericarditis?

Myocarditis is often mild, and cases usually resolve after a few days with treatment and rest. Serious cases of myocarditis can occur and have been reported in Australia and overseas. A fatal case linked to a booster dose of the Spikevax vaccine has been reported previously.

Our latest analysis of data from adverse event reports has found 57% of the patients with likely myocarditis and 19% with likely pericarditis were admitted to hospital. Twenty-four people with myocarditis and 10 people with pericarditis were treated in intensive care. This represents less than 1% of all likely cases.

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.

What does the TGA know about myocarditis and pericarditis in Australia?

Reports received by the TGA of suspected myocarditis and pericarditis for the mRNA vaccines are provided in Table 1. We have reviewed these reports against an internationally accepted criteria to classify the likelihood of myocarditis. Reporting rates of likely myocarditis and pericarditis appear similar to overseas rates and are given in Tables 2 and 3.

Reports of suspected myocarditis and pericarditis

Notes for Table 1

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

¥ The total number of reports can fluctuate slightly over time as duplicate reports may be identified and deleted and cases may be reclassified after receiving more information.

‡ 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 is 6 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 likely myocarditis

Notes for Table 2 and Table 3

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

‡ To 11 December 2022, from about 2.3 million vaccine doses given, 4 likely cases of myocarditis have been reported in children aged 5-11 years following vaccination with Comirnaty (Pfizer).

† The rates for Spikevax (Moderna) are less certain due to low numbers of cases overall and small changes in case number can lead to fluctuations in the rates for different groups.

Rates of likely pericarditis

Notes for Table 4

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

‡ To 11 December 2022, from about 2.3 million Comirnaty (Pfizer) vaccine doses given, one probable and 6 possible cases of pericarditis have been reported in children aged 5-11 years. No cases of pericarditis have been reported following Spikevax (Moderna) in this age group.

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