COVID-19 vaccine weekly safety report - 07-04-2022

Reported side effects for COVID-19 vaccines

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. More information about what to expect and how to manage any symptoms after you receive your vaccine are available from NPS MedicineWise.

Vaccine safety in children and adolescents

The TGA is closely monitoring adverse event reports in people aged under 18 years. To 3 April 2022, we have received about 4,000 reports from approximately 3.6 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 3 April 2022, we have received about 1,150 reports from approximately 1.9 million Comirnaty (Pfizer) doses administered in this age group. The most common reactions reported included chest pain, vomiting, fever, headache and shortness of breath. We have received 24 reports of suspected myocarditis and/or pericarditis in this age group. Following review of information in the reports, one was likely to represent myocarditis in a 9-year-old boy. Another 4 reports were likely to represent mild pericarditis when assessed against internationally accepted criteria for this condition. These occurred in two 10-year-old boys, a 10-year-old girl and a 7-year-old boy. All of the children have shown improvement in symptoms or recovered and those who presented to hospital have been discharged.

The latest safety data from the AusVaxSafety survey tells us that children aged 5–11 years report fewer side effects than older Australians following their second vaccine dose. About a third of children reported an expected adverse reaction compared to just over half of older individuals in the first 3 days after vaccination. Children aged 5-11 years were also less likely to see a doctor after a second vaccine dose, with medical attendance rates similar to those reported for other childhood immunisations.

Survey data also shows that as with adults, side effects appear to be more common after the second vaccine dose (reported by 33% of children) than after the first (26% of children). Most reactions are mild and temporary. Local reactions at the injection site (such as pain, swelling, redness and itching) are the most common, followed by headache and fatigue.

These observations in Australian children are in line with what was reported in the clinical trials and from real-world experience from the US, where over 8 million doses of the vaccine have been given to this age group.

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, reports of myocarditis were also very rare in the US, with 11 confirmed reports from over 8 million doses - these were all mild cases.

More information and frequently asked questions about COVID-19 vaccines in children are available on the National Centre for Immunisation Research and Surveillance website. A decision aid is now available for parents and carers who may be hesitant to get their children vaccinated.

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 experience in Australia from AusVaxSafety, recent observations from the Centers for Disease Control and Prevention (CDC) in the US and the results of clinical trials. Together with other international regulators we are monitoring the type and frequency of adverse events after different vaccine combinations.

To 3 April 2022, approximately 13 million boosters or third doses have been administered in Australia. We have received approximately 6,700 reports of suspected adverse events identified as a third or booster dose. These reports do not suggest any emerging safety concerns with use of a booster dose that is different to the first and second vaccine doses received.

Our booster or third dose reports include a small number of cases of myocarditis and pericarditis (inflammation of the heart). This is a recognised risk with the Comirnaty (Pfizer) and Spikevax (Moderna) vaccines and we are closely monitoring these events. So far, reports after booster doses are very rare with myocarditis reported in less than 1 in every 100,000 people after they receive a booster dose. A US CDC study of active and passive surveillance data( of COVID-19 vaccine booster doses (September 2021 - February 2022) found a similar trend. In men aged 18-24 years, the reporting rate of likely myocarditis was less than 1 in 100,000 mRNA vaccine booster doses compared to about 6 in 100,000 second doses. There is no indication that these events are more serious than after earlier doses. A similar US study of COVID-19 vaccine booster doses in adolescents (December 2021 - February 2022) found the reporting rate of likely myocarditis was about 1 in 100,000 Comirnaty (Pfizer) booster doses in adolescent boys who had received the Comirnaty (Pfizer) vaccine for their first and second doses. This reporting rate is lower than was observed after a second dose.

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

What we know about the safety of different vaccine combinations

Based on data from the Australian Immunisation Register, we can see that most people under the age of 50 years received 3 mRNA vaccines – this was most commonly 3 doses of Comirnaty (Pfizer). For people in the 50-59 age group, there was more of a mixed picture with over half of them receiving 3 doses of an mRNA vaccine and the rest getting an mRNA vaccine booster after receiving initial doses of Vaxzevria (AstraZeneca). In the over 60 age group, most people received an mRNA vaccine booster after getting Vaxzevria (AstraZeneca) for their first 2 doses.

For the adverse event reports received by the TGA following a booster dose, many do not give details about which COVID-19 vaccines the person received for their first and second doses. Taking into account the limitations in this reporting data, we have not observed any patterns of adverse events which suggests different vaccine combinations are more likely to lead to serious adverse events.

The US surveillance study of booster doses found that in people who had received 3 mRNA doses, adverse reactions were reported less frequently after the booster dose than after the second dose.

To improve our vaccine safety monitoring, we encourage people reporting adverse events to tell us as much information as possible about their experience, including the type of COVID vaccines they have received, and which dose the adverse event relates to.

More information about how to report a suspected side effect to a COVID-19 vaccine is available on the TGA website.

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 3 April 2022, about 56.6 million doses of COVID-19 vaccines have been given. The TGA has identified 11 reports where the cause of death was linked to vaccination from 814 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).

The 11 deaths likely to be related to vaccination occurred in people aged 34-81 years old. There have been no deaths in children, adolescents or younger adults 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. 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.

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

To 3 April 2022, about 38.7 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

The TGA is closely monitoring the safety of this vaccine in children and adults. To 3 April 2022, about 4 million doses of Spikevax (Moderna) have been administered in Australia.

The Spikevax (Moderna) vaccine can now be given to 6 - 11 year olds in Australia. This follows provisional approval by the TGA and a recommendation by the Australian Technical Advisory Group on Immunisation (ATAGI). There is not a separate paediatric formulation of the Spikevax (Moderna) vaccine. However, for the 6-11 year age group, the dose is half that used for the primary vaccine course in older children and adults. At this stage, no adverse reactions have been reported to the TGA for 6-11 year olds since the rollout started in this age group.

The Comirnaty (Pfizer) children's formulation continues to be the only COVID-19 vaccine approved for children who are 5 years of age. No COVID-19 vaccines are currently approved for children 4 years of age and under.

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).

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).

Nuvaxovid (Novavax) vaccine

The Nuvaxovid (Novavax) vaccine has been provisionally approved for adults in Australia after meeting the TGA's high standards for quality, safety and effectiveness.

To 3 April 2022, about 97,800 doses of Nuvaxovid (Novavax) have been administered in Australia. The TGA has received 424 reports of suspected adverse events. We are closely monitoring these reports. The most commonly reported reactions include headache, chest pain, paraesthesia, fatigue and dizziness. To date, no safety signals have been identified for Nuvaxovid (Novavax) based on this limited number of reports.

Paraesthesia is an unusual feeling in the skin, such as tingling or a crawling sensation, and has also been reported for other COVID-19 vaccines. It is not known why paraesthesia sometimes occurs after vaccination, but it is thought it may be a stress-related response to immunisation rather than an immune reaction.

We have 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, none were likely to represent myocarditis and 4 were likely to represent pericarditis.

We are closely monitoring these reports. To date, we have not identified a safety signal that would indicate an association between the Nuvaxovid (Novavax) vaccine and myocarditis and pericarditis.

In the AusVaxSafety survey, the most commonly reported reactions to Nuvaxovid (Novavax) are fatigue, injection-site reactions and headache. These are expected side effects that were also seen in clinical trials.

More information for Nuvaxovid (Novavax), including details about its ingredients and potential side effects, can be found in the Consumer Medicine Information (for consumers) and Product Information (for health professionals).

Vaxzevria (AstraZeneca) vaccine

To 3 April 2022, about 13.8 million doses of Vaxzevria (AstraZeneca) have been administered in Australia. However, very few doses are now being used, particularly since the end of 2021. This vaccine has recently received provisional approval to be used as a booster dose. Individuals seeking a booster dose of Vaxzevria (AstraZeneca) should discuss this with their health professional.

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 confirmed or probable TTS this year. The total number of TTS cases reported in Australia is 172. Of these, 148 (83 confirmed, 65 probable) were related to a first dose of Vaxzevria (AstraZeneca) and 24 to a second dose (5 confirmed, 19 probable). 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.

More general information for Vaxzevria (AstraZeneca), including details of 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

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.

Current evidence tells us the risk of myocarditis and other heart effects is much higher after COVID-19 infection than after COVID-19 vaccination. A recent study of patient data from 40 healthcare systems in the US found that heart complications were low overall but they were much higher after infection with the SARS-CoV-2 virus than after vaccination in males and females in all age groups. Similar findings were observed in population-based studies from Israel and the UK. In the Israeli study, COVID-19 infection was estimated to cause 11 cases of myocarditis per 100,000 people whereas the Comirnaty (Pfizer) vaccine was estimated to cause 2-3 cases of myocarditis per 100,000 people. An increase in other cardiac effects, such as pericarditis, arrhythmias and heart attacks, was also seen following SARS-CoV-2 infection in both of these studies.

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.

Do myocarditis and pericarditis occur after a booster dose?

Myocarditis and pericarditis can occur after a booster dose but this is rare. The rate of reporting of myocarditis and pericarditis is less than 1 in every 100,000 people after a booster dose. There is no indication that these events are more serious than after earlier doses.

To 3 April 2022, from approximately 13 million booster or third doses, we have received 24 reports of likely myocarditis and 61 reports of likely pericarditis for Comirnaty (Pfizer) and 15 reports of likely myocarditis and 14 reports of likely pericarditis for Spikevax (Moderna). The median age of affected individuals was 32 years old.

Myocarditis following COVID-19 vaccination is most likely to be reported in adolescents and young men, whereas the median age of people who have received a third or booster dose of a COVID-19 vaccine to date is 52 years. The TGA will continue to closely monitor myocarditis and pericarditis following booster or third doses as the booster roll-out extends to younger age groups.

We are also closely monitoring myocarditis and pericarditis with different vaccine combinations for first and second doses and boosters. At this point, although we have only a small number of reports of pericarditis and/or myocarditis, we have not seen any patterns or trends in the data to indicate any difference with mixed vaccine combinations.

Who is at risk of these heart problems?

Myocarditis is more commonly reported after the second dose in 12-17 year-old boys (12 cases per 100,000 Comirnaty doses and 20 cases per 100,000 Spikevax doses) and men under 30 (8 cases per 100,000 Comirnaty doses and 18 cases per 100,000 Spikevax doses). However, even in this population it remains rare. A similar trend for myocarditis has also been observed in a descriptive study of reporting data in the US.

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 after a second dose compared to unvaccinated individuals. For Spikevax, there were 13-19 extra cases of myocarditis per 100,000 vaccinated individuals compared to unvaccinated individuals. A study by the Centers for Disease Control and Prevention (CDC) (pdf,606kb) in the US found in 18 - 39 years olds there was approximately 2 extra cases of myocarditis and pericarditis reported per 100,000 Comirnaty (Pfizer) second doses and 3 extra cases per 100,000 Spikevax (Moderna) second doses.

How serious are myocarditis and pericarditis?

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

In the US descriptive study of myocarditis cases, the majority of those under 30 years of age were admitted to hospital but symptoms had resolved by the time they were discharged. The most common treatment for these individuals was nonsteroidal anti-inflammatory drugs, such as ibuprofen.

Evidence from a US surveillance survey (pdf,1.1Mb) of patients who had myocarditis following vaccination indicates that most patients fully recover without lasting impacts on their quality of life or ability to work. The survey, which was conducted 3 months after the initial myocarditis diagnosis, involved mostly men under 30 years after their second vaccine dose. There were no deaths from myocarditis reported in these patients.

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.

As part of our ongoing monitoring, we work with local health authorities to follow up on previously reported cases which could not be classified as likely or unlikely myocarditis or pericarditis due to insufficient information. We recently received additional information for a significant number of reports which has meant some have now been reclassified. This data has also allowed us to identify new cases likely to represent myocarditis. These revised classifications will be reflected in Table 1 over the coming weeks.

Reporting rates of likely myocarditis and pericarditis are given in Tables 2 and 3.

We have received reports of myocarditis and pericarditis after a third or booster dose. These cases are very rare and there is no indication that they are more serious than after earlier doses.

Table 1. Reports of suspected myocarditis and pericarditis received by the TGA to 3 April 2022 ^¥

		Comirnaty (Pfizer) (38.4 million doses given)		Spikevax (Moderna) (4 million doses given)
		All cases	Cases in adolescents (12-17 years)	All cases	Cases in adolescents (12-17 years)
Suspected myocarditis cases*		1,232	208	167	32
Likely myocarditis†‡	Level 1	36	7	1	0
	Level 2	373	127	67	21
	Level 3	102	12	14	3
Unlikely myocarditis		354	32	41	3
Insufficient information		367	30	44	5
Suspected pericarditis cases		2,580	170	263	11
Likely pericarditis£		900	67	82	2

* 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 additional 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 was 9 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, especially in the age categories where a low number of doses have been given. The reporting rates of likely myocarditis in the 12-17 year age group have increased since last week, particularly for females. However, this difference is not statistically significant and is due to reclassification of a few previously reported cases after receiving addition information. 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^‡ A. Comirnaty (Pfizer)

Age (years)	All doses		Second doses
	Rate* per 100,000 doses		Rate* per 100,000 doses
	Male	Female	Male	Female
12-17	7.5	1.5	12.2	2.3
18-29	4.2	1.2	7.6	2.0
30-39	1.6	0.6	2.0	0.7
40-49	0.7	0.5	1.0	1.0
50-59	0.4	0.3	0.2	0.3
60-69	0.1	0.3	0	0.4
70+	0	0.1	0	0.4
All ages*	2.0	0.7	3.9	1.1

B. Spikevax (Moderna)

Age (years)	All doses		Second doses
	Rate* per 100,000 doses		Rate* per 100,000 doses
	Male	Female	Male	Female
12-17	10.7	3.0	20.4	5.1
18-29	8.7	1.4	17.8	2.4
30-39	2.4	0.6	5.1	0
40-49	1.4	0.3	1.7	0
50-59	0.3	0.9	0	2.5
60-69	0	0.3	0	0
70+	0	0.2	0	0
All ages*	3.2	0.9	9.5	1.9

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

^‡ To 3 April 2022, from about 1.9 million vaccine doses given, no likely cases of myocarditis have been reported in children aged 5-11 years.

Table 3. Rates of likely pericarditis cases following the mRNA vaccines^‡

Age (years)	Rate* per 100,000 doses
	Comirnaty (Pfizer)	Spikevax (Moderna)
12-17	2.1	0.6
18-29	3.4	4.3
30-39	3.8	4.0
40-49	2.2	1.9
50-59	1.2	0.6
60-69	0.7	0.2
70+	0.2	0
All ages*	2.3	2.0

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

^‡ To 3 April 2022, from about 1.9 million vaccine doses given, four possible cases of mild pericarditis have been reported in children aged 5-11 years. As this number is so low, we are unable to estimate reliable rates of pericarditis in this age group.

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).

Useful links

Tested positive for COVID-19? Find out what you need to do

Watch this video to find out how the TGA monitors and reports the safety of COVID-19 vaccines

Should my child get a COVID-19 vaccine? A decision aid for parents and carers

ATAGI update following weekly COVID-19 meeting - 28 March 2022

The latest vaccine recommendations from ATAGI

Top 3 questions on COVID-19 booster doses with Professor Michael Kidd – 1 April 2022

Myocarditis and pericarditis following COVID-19 mRNA vaccines – Melbourne Vaccine Education Centre – 10 March 2022

COVID-19 vaccines: Frequently asked questions – 29 March 2022

COVID vaccines - is it true? - 17 February 2022

RMIT ABC Fact Check

Latest advice on COVID-19 vaccination for pregnant and breastfeeding women - 18 August 2021

Coronavirus (COVID-19) case numbers and statistics

Australia's COVID-19 vaccine rollout

TGA COVID-19 vaccines hub

Australian Government Department of Health COVID-19 vaccines hub

COVID vaccine information in your language

Database of Adverse Event Notifications (DAEN)

Nuvaxovid (Novavax) vaccine – clinical trials

Comirnaty (Pfizer) vaccine - phase III clinical trial

Comirnaty (Pfizer) vaccine - clinical trials in children under 12 years

Vaxzevria (AstraZeneca) vaccine - phase III clinical trial

Spikevax (Moderna) vaccine - phase III clinical trial