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ICMRA statement on the safety of COVID-19 vaccines

This International Coalition of Medicines Regulatory Authorities (ICMRA)* statement provides the general public with important information regarding the safety of COVID-19 vaccines, which have now been in use for more than two years. It also addresses some of the most common types of misinformation about COVID-19 vaccine safety.

Key messages 

  • COVID-19 vaccines significantly reduce the risk of severe disease, hospitalisation and death from infection with SARS-CoV-2. 
  • SARS-CoV-2 keeps changing and revaccination may be needed to maintain protection against new variants and continue saving millions of lives worldwide.
  • Evidence from the more than 13 billions of vaccine doses given worldwide shows that COVID-19 vaccines have a very good safety profile in all age groups. The benefits of the approved vaccines far outweigh the possible risks.
  • The vast majority of side effects are mild and temporary. However, safety monitoring (pharmacovigilance) systems have identified some very rare (occurring in less than 1 in 10,000 people) but serious side effects. Medicines regulators around the world have put in place measures to reduce the risk of harm from these side effects. 
  • As for all medicines, reports of medical events after COVID-19 vaccination (suspected side effects) are collected and continuously evaluated by the authorities. These evaluations show that in most cases the medical events were not caused by the vaccine.
  • False and misleading information about the safety of COVID-19 vaccines on social media often exaggerates the frequency and severity of side effects. Misinformation also wrongly attributes unrelated medical events to the vaccines. Vaccine misinformation leading individuals to decline vaccination has very likely led to many more deaths than adverse effects of the vaccines.
  • There is no evidence that COVID-19 vaccines have contributed to excess mortality during the pandemic. Excess mortality largely coincides with peaks of SARS-CoV-2 infections, particularly during the first waves when vaccines were not available. In fact, there is strong evidence that COVID-19 vaccines save lives and prevent the serious harm associated with SARS-CoV-2 infection.
  • Emerging evidence also suggests that long COVID is less likely to develop in people who have been vaccinated.


Benefits of COVID-19 vaccination

Millions of lives are estimated to have been saved by COVID-19 vaccination. Other benefits of vaccination include avoiding further overload of healthcare systems and allowing the reopening of societies after lockdowns.

Vaccination is one of the most important tools to prevent the consequences of SARS-CoV-2 infection. Contrary to some people’s belief that the virus is mild, SARS-CoV-2 infection can cause severe disease and long-term damage, including in previously healthy adults and children. 

Emerging scientific evidence shows that vaccines reduce the impact of long COVID. According to the World Health Organization, “an estimated 1 in 10 infections result in post-COVID condition, suggesting that hundreds of millions of people will need longer-term care”. This is because the effects of SARS-CoV-2 infection can be disabling and cause organ damage or symptoms such as fatigue, heart disease, stroke, memory loss and kidney damage, even in young, previously healthy people.

The virus continues to circulate and cause many reinfections. It can be especially dangerous for older or sick people whose immune system is weaker or does not work well.


Evidence of COVID-19 vaccine safety after use of billions of doses

By March 2023, more than 13 billion doses of vaccines have been given in mass vaccination campaigns worldwide. This includes hundreds of millions of mRNA vaccine doses given to children and pregnant women. Real-world data from vaccination campaigns show that vaccines have a very good safety profile. 

Long-term safety data of COVID-19 vaccines are very reassuring. This includes data from tens of thousands of volunteers in some of the largest clinical trials ever conducted, as well as data from mass vaccination campaigns lasting more than two years.  

As for all medicines, the more people who receive a vaccine, the more likely it is that extremely rare but potentially serious side effects will be detected. In many cases, these rare medical events (e.g. myocarditis) can also be caused by SARS-CoV-2 itself in non-vaccinated people at a higher frequency and with greater severity than after vaccination. 

Most common side effects with COVID-19 vaccines are mild and temporary. They include fever, swelling and pain at the injection site, and occur in up to 1 in 10 people. 

ICMRA countries have very solid safety monitoring systems, which continuously collect and analyse reports of suspected side effects. Regulators also initiate and analyse clinical trials and observational studies. 

The fact that a medical event has been reported as a suspected side effect does not mean that the vaccine caused it. Anyone can report a suspected side effect, including members of the public and healthcare professionals. Regulators constantly analyse these reports to see if there may be a causal link with the vaccine. They do this by comparing the rate of a medical event in vaccinated people with the rate of the event in the population before the pandemic and before vaccination. As part of this robust and continuous safety monitoring, regulators also consider any other available evidence such as evidence from studies. Most of the time, reported suspected side effects are not caused by the medicine concerned.

If any safety problem is detected, regulators take action quickly as happened when there were reports of rare cases of unusual blood clots with adenoviral vector vaccines. 

International safety monitoring systems collaborate and share vaccine data from their territories, providing invaluable insight into the safety of vaccines.

Myocarditis and/or pericarditis are very rare side effects of mRNA vaccines. They normally affect younger males and resolve with appropriate treatment. Myocarditis and pericarditis are also known complications of SARS-CoV-2 infection in non-vaccinated people. Large scale studies have demonstrated that the likelihood and severity of myocarditis due to SARS-CoV-2 infection are substantially greater than the likelihood and severity of myocarditis due to vaccination. 

Unusual blood clots with low platelets syndrome (thrombosis with thrombocytopenia syndrome or TTS) is a very rare but serious side effect of adenoviral vector vaccines. This side effect was promptly identified by safety monitoring systems following reports from healthcare professionals. Regulators immediately updated the product information to make healthcare professionals, public health authorities and citizens aware of this rare adverse reaction.

Reports of deaths following vaccination are very rare. During mass vaccination campaigns, when millions of people are being vaccinated, it is expected that some deaths will occur by chance shortly after vaccination. The fact that deaths are reported after vaccination does not mean that the vaccine caused them. Healthcare professionals can report any death that occurs following vaccination, even if it is unknown whether the vaccine was the cause. In very exceptional cases, deaths have been reported to be caused by the vaccines*1. 

*1 One example is ‘thrombosis with thrombocytopenia syndrome’ with adenoviral vector COVID-19 vaccines 


COVID-19 vaccine safety in special populations

Regulators have used real world data from mass vaccination campaigns to confirm the benefits and safety profile of COVID-19 vaccines. This information comes from millions of people in real-world conditions, which are more variable than conditions in clinical trials. 

This real world data has shown that vaccines are as safe in special populations, such as people with underlying medical conditions, immunocompromised patients and pregnant women, as they are in the general population. Vaccination of these groups is strongly recommended because they are at higher risk of complications from COVID-19. Vaccination during pregnancy protects both the mother and the baby

COVID-19 vaccines are as safe in children as they are in adults. This finding is based on data from millions of doses which have been given to children and is consistent with findings from paediatric clinical trials. Although most healthy children seem to get less sick from SARS-CoV-2 infection, children can still develop severe diseases due to SARS-CoV-2 infection, such as a rare inflammatory syndrome called MIS-C or develop long COVID. 

Sadly, some children, including healthy ones, have died due to SARS-CoV-2 infection (over 1,300 children in the US alone). In the US, a study reported that COVID-19 caused more deaths in children than other major vaccine preventable diseases did before vaccines for those diseases became available.


Long COVID and vaccines

Scientific evidence shows that infection with SARS-CoV-2 can lead to long COVID. This condition can lead to long-term organ damage (cardiovascular, metabolic, neurologic, gastrointestinal, renal, etc.) and even death several weeks or months after the initial symptoms of infection have resolved.

Several real-world data studies indicate that vaccinated people who are later infected with SARS-CoV-2 are less likely to report symptoms of long COVID than unvaccinated people. More research is needed to determine how common this is.

Some information circulating on social media has claimed that COVID-19 vaccines could be associated with long COVID. There has been no safety signal from the very large body of data held by international regulators suggesting that long COVID is a possible side effect of COVID-19 vaccination.


False information on COVID-19 vaccine safety

False information about COVID-19 vaccines can result in deaths or severe disease if people avoid getting the vaccines they need. False information about COVID-19, both unintended (misinformation) and deliberate (disinformation), spreads on social media, so it is important to get  information from trusted sources (healthcare professionals, scientific sources and national medicines regulators).

Some people misinterpret the numbers of deaths or suspected side effects reported in vaccine safety databases. The fact that an adverse medical event or even death occurs in a vaccinated person does not mean that the vaccine has caused it. Regulators evaluate reports of medical events following the use of these medicines to determine if there is a signal indicating causality and if so, they take action as appropriate.

There have also been false claims on social media that COVID-19 vaccines are to blame for the excess deaths. Many countries have had an increase in deaths since the start of the pandemic compared to what would be expected for an average year. The causal association of excess deaths with COVID-19 can be clearly seen because excess mortality peaks correspond with pandemic waves. In particular, the highest peaks in excess mortality were reached in 2020 during the early waves of COVID-19, at a time when vaccines were not yet available. While the increased mortality is associated with COVID-19, there is no evidence that COVID-19 vaccines are causing excess mortality. In fact, COVID-19 vaccines have saved millions of lives. 

There is false information circulating on social media that COVID-19 vaccines cause immune impairment and that this is causing surges in many types of other infections, including in children. There is no evidence to indicate that COVID-19 vaccination causes immune impairment. In fact, SARS-CoV-2 infection is known to cause immune impairment, especially in patients with severe COVID-19, who very often suffer from lymphopenia, and in patients with long COVID. In addition, many studies are reporting that SARS-CoV-2 infections can cause a significant number of autoimmune conditions such as diabetes.

False information has also attributed other serious health problems to mRNA vaccination, such as blood clots and strokes. These are known complications of SARS-CoV-2 infections and vaccines protect against such severe COVID-19 complications.

It is important to ensure that sources of information on vaccines are reliable and take into account the latest research. Trustworthy sources of information include healthcare professionals, scientific sources, medicines regulators and public health authorities.

False information on COVID-19 vaccine safety is dangerous and can contribute to the growing problem of vaccine hesitancy. It can also affect trust in other life-saving routine childhood vaccinations.

ICMRA strongly supports the safety of COVID-19 vaccines and their benefits in protecting people of all ages from the severe consequences of COVID-19.


ICMRA brings together 38 medicines regulatory authorities from every region in the world, with the WHO as an observer. Medicines regulators recognise the importance of facilitating access to safe, effective, high-quality products that are essential to human health and well-being. This includes keeping pace with advances in science needed to set standards and drive the decision-making process, as well as maintaining efficient regulatory processes that support the development and delivery of innovative medicinal products while ensuring that benefits of these products outweigh any associated risk.