Questions and answers on COVID-19: Vaccines

1. Which COVID-19 vaccines are available in the EU?

The following COVID-19 vaccines have been granted conditional marketing authorisation for use in the EU:

  • Comirnaty (by BioNTech and Pfizer)
  • Spikevax (by Moderna Biotech Spain SL)
  • Vaxzevria (by AstraZeneca AB)
  • COVID-19 Vaccine Janssen (by Janssen-Cilag International NV)
  • Nuvaxovid (by Novavax CZ).

2. Are COVID-19 vaccines safe?

COVID-19 vaccines continue to show a very reassuring safety profile, with more than 866 million doses administered in the EU/EEA as of March 2022. COVID-19 vaccines are developed following the same legal requirements for quality, safety and efficacy as for all other vaccines.

 Like all vaccines, the effects of COVID-19 vaccines are tested first in the laboratory, including in animals, and then in human volunteers. The European Medicines Agency (EMA) evaluates COVID-19 vaccines against the same high standards as for all other vaccines before they are released for use.

Once the vaccines are in use, national authorities and the European Medicines Agency (EMA) continually monitor their use for any side effects that may occur in people who have received the vaccine. As with any medicine, some people may experience side effects from a vaccine, but these are usually mild and short-lived. As for all vaccines, close medical supervision is important upon administration of the vaccine.

3. Are COVID-19 vaccines effective?

COVID-19 vaccines authorised for use in the EU/EEA have been very effective at preventing severe disease, hospitalisation and death.

In general, benefits of COVID-19 vaccines may include:

  • preventing SARS-CoV-2 infection in vaccinated individuals
  • reducing disease severity, if vaccinated individuals are infected
  • preventing death in vaccinated individuals
  • reducing the number of people infected in populations with adequate vaccine uptake
  • reducing virus transmission in populations with adequate vaccine uptake.

Regulators such as the European Medicines Agency (EMA) approve vaccines once studies confirm that the vaccine’s benefits exceed any potential risks. Following conditional marketing authorisation and deployment of COVID-19 vaccines, observational studies collect data on the effectiveness of the vaccines in real life, allowing for the monitoring of how these perform over time and in different populations.

Results from observational studies confirm that the vaccines authorised in the EU/EEA are highly protective against COVID-19-related severe disease, hospitalisation and death, including for infections caused by the more recent Omicron variant. Therefore, vaccination continues to play a significant role in preventing severe clinical outcomes.

However, protection wanes over time. Though a primary vaccination course is effective against the Delta variant, it is less effective against Omicron infection and symptomatic disease. A full primary vaccination course and an additional or booster dose are significantly more effective against Omicron infection and symptomatic disease.

Giving an additional or booster COVID-19 vaccine dose to eligible age groups following a full primary vaccination course is therefore critical to ensure higher and more sustained levels of protection.

The effectiveness of COVID-19 vaccines needs to be continuously monitored. This is key to detecting any signs of reduced protection or lessened effectiveness against circulating variants. As this is an area of evolving evidence, vaccine recommendations or vaccination strategies may need to be adjusted accordingly.

4. What are ECDC’s recommendations regarding COVID-19 vaccination?

With the continued high circulation of SARS-CoV-2 in EU/EEA countries, ECDC strongly encourages those who are eligible for vaccination but have not yet been vaccinated to get fully vaccinated against COVID-19 in a timely manner.

In addition, to tackle waning protection against symptomatic disease over time, it is important to get a booster dose as soon as possible, as per national recommendations.

5. Do vaccinated individuals still need to apply personal protective measures?

Vaccinated individuals should continue to follow public health measures, as per national recommendations. People who are vaccinated can still get infected and infect others, though this occurs much less often than in people who are unvaccinated.

Measures to limit the transmission of SARS-CoV-2 are especially important in settings with people at high risk of severe disease and hospitalisation, such as in long-term care facilities. In such settings, non-pharmaceutical interventions need to be implemented meticulously and according to national recommendations, regardless of whether there is high vaccination coverage. These can include, for example:

  • ensuring proper ventilation
  • implementing the use of face masks for all long-term care facility staff and all contacts involved in resident care (particularly while indoors), irrespective of an individual’s vaccination status
  • practicing physical distancing.

6. Will COVID-19 vaccines stop the pandemic?

It is likely that SARS-CoV-2, the virus that causes COVID-19, will continue to circulate and evolve. It is not possible to predict how infectious or severe new variants of the virus will be. It is therefore very important to achieve and maintain high vaccination coverage across all communities and population groups, at national and international levels. Vaccination remains a key component of the multi-layered approach needed to reduce the impact of SARS-CoV-2.

As of March 2022, uptake of the primary vaccination course of COVID-19 vaccine has been slowing down in EU countries and not enough people are getting booster doses. More efforts are needed to ensure more people get fully vaccinated and receive booster doses, in order to increase levels of protection and reduce the spread of SARS-CoV-2 . This is especially important for those at highest risk of severe disease and particularly in the context of highly transmissible variants like Omicron.

In the meantime, all measures for controlling the spread of the virus – physical distancing, appropriate hand hygiene, respiratory etiquette and the use of face masks where required – are still important.

7. Can COVID-19 vaccines protect people against the virus when it has mutated?

Vaccines against some viral diseases remain effective for many years and provide long-lasting protection. Others, such as the flu vaccine, need to be regularly updated to remain effective. This is because viruses constantly mutate when they circulate among people.

Many SARS-CoV-2 mutations have no impact on vaccine effectiveness, but some may be of concern and could potentially reduce how well the existing vaccines work. Scientists around the world are carefully monitoring mutations of SARS-CoV-2 virus to assess how well the currently available COVID-19 vaccines can protect against them.

To date, studies show that the COVID-19 vaccines authorised in the EU/EEA are currently highly protective against COVID-19-related severe disease, hospitalisation and death, including during circulation of the highly transmissible Omicron variant. However, vaccines are less effective against Omicron, compared to previous variants.

Vaccine producers and scientists around the world are exploring ways to update existing vaccines as necessary to improve protection as new variants are detected.

8. Is COVID-19 vaccination still necessary, even after getting infected with the virus and recovering?

People who have recovered from a prior infection are less likely to get infected with SARS-CoV-2 and have severe outcomes from COVID-19 (hospitalisation, ICU admission and death), when compared with individuals who have not been infected. However, protection is enhanced by vaccination.

Studies show that reinfections with SARS-CoV-2 occur even in people who have had COVID-19. Furthermore, the Omicron variant has led to more reinfections among recovered people when compared with the previously circulating Delta variant.

Evidence is growing that vaccination after infection strengthens protection and further reduces the risk of reinfection. Therefore, COVID-19 vaccination is generally recommended for the eligible population, including those who have recovered from the disease.

9. How is COVID-19 vaccination progressing in the EU/EEA?

The COVID-19 Vaccine Tracker provides information on the uptake of first and second doses of COVID-19 vaccines, as well as an additional or booster dose, at the national level and by age, other target groups and vaccine products, for EU/EEA countries.

10. Are combined or so-called ‘mixed’ vaccination schedules using two different vaccine products safe and effective?

Combined (also referred to as ‘heterologous’ or ‘mixed’) COVID-19 vaccination schedules involve using one type of vaccine for the first dose and a different type of vaccine for the second dose. These mixed schedules are generally well tolerated and may even induce better protection against COVID-19.

Furthermore, available evidence indicates that using the same vaccine for the primary vaccination course and then a different vaccine for a booster dose appears as good as or better than using the same vaccine for all doses, in terms of immune response.

In particular, receiving an mRNA vaccine for the booster dose when the primary vaccination series was with a viral vector vaccine can improve protection.

Mixed schedules are not new in immunisation and have been used in the past for vaccines against other diseases. Several EU/EEA countries are currently using different combinations of mixed vaccine schedules. Current evidence indicates that these approaches are safe and create a satisfactory immune response.

11. Is an additional or booster dose of COVID-19 vaccine necessary?

Based on current evidence, more people who are fully vaccinated (i.e. those who have completed a primary vaccination course) should get booster doses, particularly given the high transmissibility of the Omicron variant.

This is especially important for older and high-risk individuals, in particular those living in closed settings (e.g. long-term care facilities). This is due to emerging evidence that vaccines can become less effective more quickly among older age groups and residents of long-term care facilities.

Some countries have already started to administer a second booster dose to older and high-risk groups, as many individuals in these groups received their first booster dose several months ago.

Additional doses after the primary vaccination course should also be administered to people with severely weakened immune systems, according to national recommendations. In these instances, additional doses are not considered ‘booster doses’, but an extension of the primary vaccination course, as these persons may not achieve adequate protection from the primary course.

Booster doses are given to fully vaccinated people to restore protection after it has partially waned. The European Medicines Agency (EMA) assesses the data on additional and booster doses to consider whether updates to the product information are appropriate.

According to the evidence that is currently available, booster doses will increase protection, particularly against severe disease, with the population impact expected to be higher if the booster dose is given to most of the adult population.

13. Should adolescents and/or younger age groups be vaccinated against COVID-19?

The decision of whether to include younger age groups in the COVID-19 vaccination programme is taken at the national level.

Children and adolescents who have underlying conditions that put them at higher risk of severe COVID-19 should be considered a priority group for vaccination against COVID-19, as in other age groups. This is to ensure they are protected against severe disease and hospitalisation.

Children and adolescents with no known risk factors are also susceptible to severe disease and hospitalisation, even though COVID-19 infections in these age groups are generally mild and hospitalisation rates remain at much lower levels than in adults.

Vaccination in children and adolescents also reduces the risk of serious complications, such as post-COVID-condition (‘long COVID’) and multi-inflammatory syndrome in children (MIS-C).

MIS-C is a rare condition that can cause:

  • cardiovascular symptoms
  • persistent fever
  • inflammation
  • gastrointestinal manifestations

Vaccination in these age groups can help to limit the spread of disease, and therefore prevent learning disruptions due to school closures or quarantine practices and allow for sports and social activities. Vaccination can also reduce the possible transmission to more vulnerable groups.

The European Medicines Agency (EMA) has authorised the use of the COVID-19 vaccine Comirnaty in children aged five years and older and Spikevax in children aged six years and older. Most EU/EEA countries are recommending vaccination of all children five years and older (28/30 countries, as of March 2022, with the other two countries recommending it only to children in risk groups).

Page last updated 26 Apr 2022