COVID-19 vaccines: key facts
The European Medicines Agency (EMA) helps ensure that COVID-19 vaccines offer continued protection against the SARS-CoV-2 coronavirus, including variants such as Delta and Omicron, by working with European Union (EU) and international partners. The information below explains how EMA evaluates data and makes recommendations on the protection provided by vaccines, their safety, vaccination in children, boosters and related topics.
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All COVID-19 vaccines authorised in the EU offer good protection against severe disease, hospitalisation and death caused by variants of the SARS-CoV-2 virus. These include Omicron and its sub-variants.
Omicron and its sub-variants are more able to infect vaccinated people than other variants such as Delta.
Vaccines continue to play a crucial role in preventing severe COVID-19 disease: unvaccinated people remain at much higher risk of falling severely ill with COVID-19, compared to people who have been vaccinated.
EMA continues to work very closely with the European Centre for Disease Prevention and Control (ECDC) and the World Health Organization (WHO) to assess how well vaccination protects against Omicron and its sub-variants, and the degree to which protection against hospitalisation and death endures.
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Infections in vaccinated people are not unexpected. They can happen partly due to the decrease over time in the protection offered by vaccination, the emergence of more transmissible variants that are better at escaping the body’s immune system, and changing social measures such as distancing and mask wearing.
No vaccine is 100% effective. Although authorised vaccines offer a high level of protection against hospitalisation and death, some vaccinated people may still develop severe COVID-19 and be hospitalised, or even die, particularly those with underlying health conditions.
When infection rates increase, the chance that vaccinated people get COVID-19 rises.
Omicron and its sub-variants are more able to infect vaccinated people than earlier variants. However, vaccinated people will be better protected from severe disease if breakthrough infections occur
So far, in Europe, authorised vaccines are estimated to have saved hundreds of thousands of lives among people aged 60 years and over.
For more information, see:
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Adapted vaccines are updated versions of existing vaccines designed to better match the latest SARS-CoV-2 virus variants in circulation.
They work in the same way as the originally authorised vaccines, but are expected to provide broader protection against different variants as the SARS-CoV-2 virus evolves.
A number of adapted vaccines are now authorised in the EU. They are bivalent vaccines targeting the original SARS-CoV-2 virus strain and specific Omicron sub-variants called BA.1 or BA.4-5.
EMA continues reviewing adapted vaccines as more data on their effectiveness become available.
More information:
- EMA recommends approval of second adapted Spikevax vaccine (19/10/2022)
- Adapted vaccine targeting BA.4 and BA.5 Omicron variants and original SARS-CoV-2 recommended for approval (12/09/2022)
- First adapted COVID-19 booster vaccines recommended for approval in the EU (01/09/2022)
- Adapted COVID-19 vaccines
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All adapted vaccines authorised in the EU can be used as a booster dose in people aged 12 years and above who have received at least a primary course of vaccination against COVID-19.
Comirnaty Original/Omicron BA.4-5 can also be used as a booster in children aged 5 to 11 years. Spikevax bivalent Original/BA.1 can be used as a booster in children aged 6 to 11 years.
Adapted mRNA vaccines targeting the original SARS-CoV-2 strain and Omicron BA.4-5 sub-variants may also be used for primary (initial) vaccination.
National health authorities decide who receives an adapted vaccine and when in each EU country.
Recommended priority groups include people aged 60 years and above, pregnant or immunocompromised people, residents and staff of long-term care homes and healthcare workers.
For more information, see:
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Each EU Member State decides which COVID-19 vaccines to administer as part of national vaccination campaigns.
National health authorities consider all relevant factors, such as the spread of infection and new variants in their country and the impact of COVID-19 in different populations.
There is no need to wait for a specific adapted vaccine. If health authorities offer you a given vaccine, it is important that you follow their recommendations and get vaccinated.
Timely vaccination will help protect you against COVID-19, especially in view of a possible surge of COVID-19 cases in winter.
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For an adapted vaccine to be authorised in the EU, all available data from the originally authorised vaccine and its adapted version(s) are evaluated.
Data show that adapted vaccines are effective at triggering an immune response against the original SARS-CoV-2 virus strain and the specific strain(s) it targets.
There must also be quality and manufacturing data showing that an adapted vaccine meets EU standards.
The side effects seen with the adapted vaccines are comparable to the originally authorised vaccines, and are typically mild and short-lived.
EMA follows the emergence and spread of new variants together with the ECDC and requires all vaccine developers to investigate if their vaccines protect against emerging variants and provide their findings to EMA.
The Agency continuously monitors the safety and effectiveness of all vaccines authorised in the EU.
For more information, see:
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There is evidence that protection against infection and particularly against mild disease decreases around six months after primary vaccination. However, because protection against severe disease lasts longer, in the EU most cases of severe disease occur in unvaccinated people.
At present, it is not known how long immunity (protection) against COVID-19 will last after a booster dose.
The duration of immunity is influenced by several factors. For instance, immunity drops faster in men, older people and those with other health problems.
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People with weak immune systems may need an additional dose as part of their primary (initial) vaccination to be properly protected against COVID-19.
They are also advised to get booster doses when recommended to do so by national authorities. This is to ensure they continue to be protected.
Studies in organ transplant patients with weak immune systems have shown that an additional dose increases the ability to produce antibodies against SARS-Cov-2. Based on a review, EMA has advised that an additional dose should be given to people with a severely weakened immune system.
EMA continues to evaluate new evidence on additional doses with all COVID-19 vaccines in people with weak immune systems.
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Vaccines protect from infection and serious disease. They have reduced the impact of the SARS-CoV-2 virus and remain a crucial tool to fight the pandemic.
Some medicines to treat or prevent COVID-19 have been authorised in the EU, following evaluation by EMA.
These medicines complement vaccines in the fight against COVID-19. They particularly help vulnerable groups, people who do not respond adequately to vaccination, or those who cannot be vaccinated
In December 2022, EMA’s Emergency Task Force (ETF) warned that some medicines authorised for treatment of COVID-19 were unlikely to be effective against emerging Omicron sub-variants.
For more information, see:
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Yes, people who have recovered from COVID-19 infection can still be vaccinated.
Natural immunity (immunity following natural infection) decreases over time, so getting vaccinated helps develop a stronger ability to fight future infections and protect against serious disease.
Each EU Member State is responsible for deciding who is vaccinated and when, including people who have been infected.
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People who have been vaccinated can still pass on the SARS-CoV-2 virus to others.
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Boosters are essential to restore immunity (protection), particularly against severe disease which poses the risk of hospitalisation and death.
A booster dose is recommended for adults and may be considered for children over 5 years of age.
A second booster with an mRNA COVID-19 vaccine should be considered for people aged 60 years and above, and for vulnerable persons.
EMA assesses the benefits and risks of boosters. However, EMA does not decide how or when boosters are given to people in EU countries (see also the section 'Differences across the EU').
For more information:
- ECDC and EMA update recommendations on additional booster doses of mRNA COVID-19 vaccines (11/07/2022)
- ECDC and EMA issue advice on fourth doses of mRNA COVID-19 vaccines (06/04/2022)
- EMA and ECDC recommendations on heterologous vaccination courses against COVID-19: ‘mix-and-match’ approach can be used for both initial courses and boosters (07/12/2021)
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Yes, and they also provide high levels of antibodies in adults.
Currently, it is not known how long protection after a booster will last.
Recent evidence, including real-world effectiveness data, suggests that people who have had a booster dose appear to be better protected against the Omicron variant of SARS-CoV-2 than those who have only received their primary course vaccination.
Experience with vaccines against other diseases than COVID-19 has shown that some require several doses in order to ensure long-term protection (such as vaccines against hepatitis B). Others, like the vaccine against flu, need annual updates. This may become necessary with COVID-19 vaccines.
EMA will gain a better understanding of how long protection lasts, taking account of the spread of virus variants, as more data from vaccination campaigns and ongoing studies become available.
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Using a different vaccine for the second dose, or as a booster dose, is safe and effective.
Such a ‘mix and match’ approach - known as a heterologous vaccination - has been used successfully with other vaccines in the past.
Most EU Member States have already decided to use a different vaccine for the second dose in their vaccination campaigns. For example, some countries have been offering people Comirnaty (developed by BioNTech and Pfizer) or Spikevax (developed by Moderna) after a first dose of Vaxzevria (developed by AstraZeneca).
The data currently available suggests that there is a satisfactory immune response with this approach, and that there are no safety concerns.
EMA is reviewing all new data on this topic as they become available to be able to make specific recommendations for each vaccine.
For more information, see:
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Several studies have shown that mRNA COVID-19 vaccines do not cause complications of pregnancy in expectant mothers or their babies.
People who are pregnant or who might become pregnant soon are encouraged to receive COVID-19 vaccines in line with national recommendations.
People infected with SARS-CoV-2 while pregnant are more likely to become severely ill with COVID-19 than people who are not pregnant, especially in the second and third trimesters.
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The information currently available on the use of COVID-19 vaccines during pregnancy mainly comes from studies looking at the mRNA vaccines Comirnaty and Spikevax. These studies involved more than 65,000 people who were at various stages of pregnancy.
The studies have not shown any signs that these COVID-19 vaccines increase the risk of complications of pregnancy, miscarriage, premature birth or harm to the unborn baby.
The data have also confirmed that the vaccines reduce the risk of hospitalisation and death in pregnant people, as they do in people who are not pregnant.
Side effects are similar to those seen in vaccinated people. They are mostly mild or moderate, and recede within a few days.
For more information, see:
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COVID-19 is generally mild in children of all ages, although severe cases leading to hospitalisation do occur rarely. Children with an underlying illness are more likely than others to be admitted to hospital.
Current evidence indicates that the Omicron variant in circulation causes less severe disease than other variants but is more infectious. According to data from the European Centre for Disease Prevention and Control (ECDC), cases and hospitalisations of children with COVID-19 have increased in the EU after July 2021, including the period of time since Omicron started spreading.
ECDC has published interim considerations for vaccinating children 5-11 years old. An update on the effects of Omicron in children will be provided as further data become available.
For more information, see:
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COVID-19 vaccines are as effective in children as they are in adults, as current evidence shows.
EMA evaluated data for using Comirnaty (BioNTech / Pfizer) and Spikevax (Moderna) in children from 6 months of age. It found that antibody levels against SARS-CoV-2 after vaccination in children were comparable to those in adults.
In addition, available evidence indicates that the immune response to a booster dose of Comirnaty or Spikevax in children and adolescents is comparable to that in adults.
Data on the effectiveness against the Omicron variant in children are still emerging. However, preliminary data from adults show COVID-19 vaccines remain effective against severe disease and hospitalisation caused by the Omicron variant.
There are currently limited data on how long protection in children lasts.
For more information, see:
- Comirnaty COVID-19 vaccine: EMA recommends approval for children aged 5 to 11 (25/11/2021)
- EMA starts evaluating use of COVID-19 vaccine Spikevax in children aged 6 to 11 (10/11/2021)
- EMA recommends authorisation of booster doses of Comirnaty from 12 years of age (24/02/2022)
- Preliminary data indicate COVID-19 vaccines remain effective against severe disease and hospitalisation caused by the Omicron variant (11/01/2022)
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COVID-19 vaccines are well tolerated in children, according to data from the United States and EU, where millions of children have already been vaccinated. EMA is assessing these and all other real-world data as they become available.
The side effects of these vaccines are usually mild or moderate and go away in a few days, based on clinical trials previously carried out in children. The most common side effects seen in trials were injection site reactions, nausea and vomiting. In young infants, irritability, sleepiness and loss of appetite were also very common after vaccination.
Very rare cases of myocarditis and pericarditis (inflammatory conditions affecting the heart) have occurred in adolescents and adults after vaccination with mRNA vaccines. As with myocarditis or pericarditis unrelated to vaccination, these conditions usually recede following treatment.
EMA will continue monitoring data on safety in children as vaccinations continue.
For more information, see:
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A company developing a COVID-19 vaccine must have a paediatric investigation plan (PIP) in place before their vaccine is authorised for adults. The plan outlines all the studies the company needs to carry out to support the vaccine’s authorisation in children.
EMA has evaluated studies carried out as part of PIPs. These include studies that looked at how well the vaccines triggered an immune response in children compared with adults, as well as safety and efficacy studies in children, involving up to 3,000 participants.
The Agency also considered the data from large studies in adults, including studies with up to 44,000 participants, and reports of side effects in adults. These may be relevant for children because of the similarities in how children and adults respond to vaccines.
EMA will continue evaluating data on these vaccines, including large amounts of real-world data on children from around the world.
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In the EU, national authorities advise on vaccinating children as part of national vaccination campaigns in each country. They consider the overall situation in their country and the effects COVID-19 is having on different groups of people.
If you have any questions about vaccinating your child, you can also discuss these with a healthcare professional, particularly if your child has an underlying illness that puts them at higher risk of severe COVID-19.
More information on the use of COVID-19 vaccines, including in children where applicable, is available on the dedicated webpages for each authorised vaccine:
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Each EU Member State is responsible for its own national COVID-19 vaccination campaign. This includes who should be vaccinated and when, when children should be vaccinated and who should get a booster.
Each country needs to take its own specific situation into account, such as the spread of the virus, vaccine availability and capacity of the health system.
EMA is not involved in national vaccination campaigns.
In each Member State, advisory bodies called national immunisation technical advisory groups (NITAGs) are responsible for providing advice on how the Member State should give vaccinations. These bodies are best placed to take account of local conditions.
EMA is not involved in national vaccination campaigns. Nor is the Agency involved in negotiating potential vaccine availability, funding or deployment at EU or national level after authorisation.
For more information, see:
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Each country needs to take its own specific situation into account, such as the spread of the virus, vaccine availability and capacity of the health system. Countries may decide to use the vaccines at their disposal differently.
EMA’s scientific evaluations are the foundation upon which individual EU Member States design and implement their own national vaccination campaigns.
EMA’s evaluations define the benefit-risk balance of each vaccine in the different populations studied. The benefits of all the currently authorised COVID-19 vaccines outweigh the risks when used as described in the product information.
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EMA is not involved in advising on travel requirements in the EU - such as on vaccination, quarantine or testing for travellers.
EU Member States can take decisions on which COVID-19 vaccines are included in the EU Digital COVID Certificate and the length of their validity.
Member States can apply broader criteria when accepting COVID-19 vaccines for travel purposes. These can include, for example, World Health Organization (WHO) listed vaccines that have not necessarily undergone the EMA process of authorisation, but that have been approved in other countries.
Decisions on how vaccinations are deployed also fall under the responsibility of each Member State.
For its part, EMA is responsible for the scientific evaluation of vaccines seeking EU marketing authorisation, and monitoring their safety.
Official information on this topic is available in all EU languages at:
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The World Health Organization (WHO) has made recommendations for an emergency use listing (EUL) for some COVID-19 vaccines. These are not marketing authorisations, but are designed to support temporary availability and use in emergency situations.
Each WHO Member State can allow the emergency use of a product under an EUL in their country.
However, in the EU, WHO recommendations for EUL cannot replace the centralised authorisation procedure involving a scientific evaluation by EMA.
An EU marketing authorisation offers a robust post-authorisation regulatory framework based on legally binding obligations, safeguards and controls.
For more information, see:
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Safety information can be found in the product information, available on the vaccine medicine page of each authorised COVID-19 vaccine.
For more information, see:
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Since the first COVID-19 vaccines were authorised in December 2020, EMA has published monthly safety updates to communicate PRAC’s evaluation of global safety data.
The majority of the EU population has now received at least one COVID-19 vaccine. Data from related clinical trials, other studies and spontaneous reporting have helped establish the safety profile of these vaccines.
The publication of the monthly updates has therefore ceased after the December 2022 issue.
As for all medicines authorised in the EU, emerging safety data will continue to be monitored and assessed.
As of January 2023, relevant changes to the product information of COVID-19 vaccines are communicated via the PRAC highlights. Dedicated public health communications may also be issued, if needed.
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COVID-19 vaccine developers need to submit specific data on their vaccine. EMA then carries out a thorough assessment of these data to reach a scientific opinion on whether the vaccine is safe, efficacious and of good quality, and is therefore suitable to vaccinate people.
Efficacy is measured by looking at how well the vaccine works in clinical settings, for example how well the vaccine prevents symptomatic disease.
For more information on the studies required for approval, see:
Did you know..?
The data submitted in a marketing authorisation application for a COVID-19 vaccine must include information on:
- the group of people to be given the vaccine;
- its pharmaceutical quality, including information on the identity and purity of the vaccine components and its content, and biological activity (potency);
- data on each step of manufacturing and on the controls used to ensure that each batch of vaccine is consistently of good quality;
- compliance with international requirements for laboratory testing, vaccine manufacture and conduct of clinical trials (‘good laboratory practice’, ‘good clinical practice’ and ‘good manufacturing practice’);
- types of immune responses induced by the vaccine;
- the effects observed in the groups of people to be given the vaccine;
- the vaccine’s side effects observed in vaccines, including if there are any data in special populations such as older people or pregnant women;
- information intended to be gathered from follow-up studies after authorisation (e.g. long-term safety data or long-term immunity);
- prescribing information to be provided to patients and healthcare professionals (i.e. the summary or product characteristics or SmPC, labelling and package leaflet), which is drafted by the developer and reviewed and agreed by EMA’s scientific committees;
- the way risks will be managed and monitored once the vaccine is authorised; the risk management plan (RMP), evaluated by PRAC, is a document with information on possible (known or potential) safety concerns, post-authorsation management and monitoring, and information gathering from follow-up studies.
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COVID-19 vaccines need rapid distribution to billions of people across the world.
This poses a challenge for any company developing a COVID-19 vaccine. It is the same for vaccines made using traditional or new methods.
Some developers decided to start producing COVID-19 vaccines earlier than usual, before their vaccine was authorised. They still had to uphold the same good manufacturing practice (GMP) standards that apply to all vaccine manufacturers in the EU.
For more information, see:
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EMA's human medicines committee (CHMP) evaluates marketing authorisation applications for COVID-19 vaccines. For more information, see:
CHMP evaluates scientific data submitted by the company to determine whether the vaccine’s benefits outweigh its risks.
All COVID-19 vaccines authorised in the EU initially received a conditional marketing authorisation, which was valid for one year.
The companies that market the vaccines apply to have their authorisations renewed every year. The renewal process can take up to six months, including up to 90 days for EMA's evaluation.
EMA has evaluated substantial additional information on safety and effectiveness of COVID-19 vaccines gathered since they were first authorised. Most vaccines have now been granted full marketing authorisation after their latest renewal.
To check the vaccines' current status, see:
For more information on conditional marketing authorisation and annual renewal, see:
For information on the COVID-19 vaccines EMA is currently evaluating, see:
To read more about the studies EMA requires for approval, see:
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The European Commission has authorised several vaccines to prevent COVID-19 in the EU, following evaluation by EMA. For the latest details, see:
EMA is evaluating data on the following COVID-19 vaccines:
Effective vaccines, together with other public health measures and therapeutic treatments, are a key component in overcoming COVID-19.
Did you know..?
Vaccines work by preparing a person's immune system (the body’s natural defences) to recognise and defend itself against a specific disease.
COVID-19 vaccines work by generating immune responses to all or part of a protein (spike protein, or protein S) that is unique to the virus that causes COVID-19.
If the person is infected by the virus later on, the immune system recognises the virus and, because it is already prepared to attack the virus, protects the person from getting sick with COVID-19.
For more information, see:
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To speed up the assessment of a promising vaccine, EMA evaluates data as they become available. This is done during the development as part of a rolling review, before a formal application for marketing authorisation is submitted.
Some vaccine manufacturers are able to submit the required data earlier, allowing the rolling review to progress faster.
This also means that, once an application for marketing authorisation is submitted, it takes less time for EMA to reach an opinion on whether the vaccine should be authorised. This happens because most of the data has already been assessed during the rolling review.
For more information, see:
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COVID-19 vaccines are developed following the same legal requirements for pharmaceutical quality, safety and efficacy as other medicines.
Like all medicines, COVID-19 vaccines’ effects are first tested in the laboratory, including in animals, then vaccines are tested in human volunteers.
For more information, see:
Did you know..?
What is different for COVID-19 vaccines, compared to other medicines, is that the speed of development and approval is much higher due to the public health emergency.
EMA has put in place a dedicated expert task force and rapid review procedures to evaluate high-quality applications from companies in the shortest possible timeframes, while ensuring robust scientific opinions.
The European Commission makes use of all existing flexibilities to accelerate the approval of any potential vaccines for use across the EU. However, this is only possible if EMA receives sound scientific evidence establishing that a vaccine's benefits are greater than any of its risks.
You can find more information on how vaccines and other medicines are evaluated and authorised in the EU on:
- COVID-19 vaccines: development, evaluation, approval and monitoring
- European Vaccination Information Portal
- Authorisation of medicines
- How EMA evaluates medicines for human use
- From laboratory to patient: the journey of a centrally authorised medicine
- European Commission: Safe COVID-19 vaccines for Europeans
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For each authorised vaccine, EMA publishes the full assessment report, which describes in detail the data assessed and explains why EMA recommended approving authorisation.
EMA also publishes a medicine overview containing a summary of the main studies and their results.
For more information on each authorised vaccine, see:
EMA also publishes the clinical study results submitted by COVID-19 medicine developers in support of their marketing authorisation applications, including any extensions of indication and any negative opinions. More details are available:
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EMA recommends the following trustworthy sources of information:
- European Vaccination Information Portal
- European Centre for Disease Prevention and Control
- World Health Organization
- National health authorities
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EMA cannot provide an estimate of when a scientific evaluation will conclude. This applies both to a rolling review and the evaluation of a marketing authorisation application.
It depends on the specifics of the application and how quickly the company can respond to questions from EMA.
A review that is currently ongoing follows the same procedure as previous reviews that led to COVID-19 vaccines being authorised.
As soon as EMA reaches a conclusion on a COVID-19 vaccine it makes this information public. A simple way to check is by referring to:
It is up to EU Member States to decide if and how to offer a centrally authorised COVID-19 vaccine as part of its national vaccination programme. This depends on the vaccine's availability and other factors mentioned above.
EMA is not involved in these decisions and cannot advise on the future availability of a vaccine currently under evaluation.
- European Vaccination Information Portal
- European Commission: Safe COVID-19 vaccines for Europeans
Council of the EU: COVID-19 vaccines: Why so fast?- Council of the EU: mRNA vaccines: What gets injected into my body?
- The World Health Organization (WHO)
- European Centre for Disease Prevention and Control (ECDC)