Q&A

All vaccines in use in Europe have to meet strict safety standards and demonstrate that their benefits outweigh any risks.  

However, some people may be advised by their doctors not to get vaccinated due to their personal medical situation.  

This could be because they have problems with their immune system due to a disease (like leukaemia or multiple myeloma) or other medicines they are taking (such as medicines to prepare them for an organ transplant or to treat certain cancers).  

When people have such problems with their immune system, their body may respond differently to vaccination. People may also need to avoid certain vaccines because they are allergic to one or more of their ingredients. For example, in some types of vaccines there could be trace amounts of other substances used in the manufacturing process, such as ovalbumin (a protein found in eggs) or neomycin (an antibiotic). 

Decisions on whether or not to vaccinate for medical reasons should always be taken with a doctor’s advice.  

While contracting many diseases provides people with a level of immunity after recovery, this is not the case for all diseases. Getting sick also puts people at much greater risk of developing complications from the disease and spreading it to others. Vaccination is the safest way to provide enduring protection against a disease. 

Vaccination against a disease carries much less risk than the disease itself. In addition, getting sick will also put your loved ones and community at risk of getting infected.  

Even though no medicines or vaccines are 100% effective, vaccination offers us our very best chance at protection from vaccine-preventable diseases. 

When it comes to diseases like the flu or COVID-19, there are many different strains or mutations that can circulate at one time. In such cases, vaccines are usually updated to protect against the most common forms of the flu or COVID-19 that season. This can mean that we can still get sick if we are exposed to a strain against which the vaccine may not be as effective. 

People who have been vaccinated and still get  sick generally experience milder symptoms and are much less likely to develop severe disease or complications. 

No vaccine changes or interacts with human DNA.  

DNA is stored in the nucleus of our cells and is extremely well protected. Some COVID-19 vaccines use mRNA (messenger RNA) to teach your body how to fight the virus that causes COVID-19, but these do not interact with your DNA in any way, as mRNA does not enter the nucleus. 

Instead, this mRNA stays in the outer area of the cells and is only used to make a small part of the virus so your body can learn how to protect itself. Once this is done, the mRNA is broken down very quickly.  

mRNA vaccines have been studied for decades and there is no evidence of them changing our DNA.   

Vaccines have been used in Europe for more than a century and have shown to be carry significantly less risk than the diseases they protect against. 

All vaccines in use in the EU/EEA go through a rigorous approval process. Once they are in use, doctors, regulators and other health authorities constantly look out for reports of suspected side effects of vaccines, as is done for all medicines. This safety monitoring process is known as pharmacovigilance. 

Some vaccines can cause minor side effects, like discomfort at the injection site or headache, shortly after being administered, but there is no evidence that any vaccines in use today can cause any long-term ill effects to a person’s health.   

For more detailed information on this topic, please visit our pages on vaccine approval, and safety and side effects.

Thanks to vaccination, some diseases occur very rarely in Europe. In addition, Europe is polio free, but this disease is still found in some parts of the world.  

If the number of people being vaccinated against polio in Europe falls, there is a chance that this disease could spread from these areas back to Europe and other places where it had been wiped out. 

Vaccination is therefore vital to make sure that diseases that are very rare or that do not occur anymore in Europe do not make a comeback. 

Vaccines do not cause autism. Researchers across the world have searched for any link in hundreds of studies, and there is no evidence of any link.  

The study from 1998 that proposed a link between vaccines and autism contained fabricated data and has been widely discredited by scientists and doctors. The scientific journal that published the study retracted it. The lead author was struck off the United Kingdom’s medical register and is no longer allowed to practice medicine.  

There is no evidence for a link between vaccination and autism and hundreds of subsequent studies confirm this. Researchers across the world have searched for any link and been unable to find one.  

All vaccines approved for use in Europe go through a lengthy approval process to demonstrate their safety and are continually monitored for side effects once approved.  

Vaccines do not contain dangerous chemicals. All vaccines have to meet strict safety standards before they are authorised for use in Europe.  

Some vaccines contain substances that may sound worrying, such as aluminium salts and residual amounts of formaldehyde. These substances are always added in tiny and safe levels, and their addition is essential for the vaccine to work properly. 

For example, the amount of formaldehyde contained in some vaccines is lower than the amount that the human body naturally produces to make sure our body can function.  

Aluminium salts have safely been used in some vaccines since the 1930s. Small amounts of aluminium salts can be found in foods and drinking water. In some vaccines, they play a vital role in enabling the vaccine to protect a person from disease.  

Levels of all vaccine ingredients are carefully controlled to ensure they are present at levels that are safe. Regulators check that the benefits of vaccines are greater than the risk of any possible reactions to their ingredients. 

Vaccination helps protect people from diseases. Because vaccinated people have a much lower risk of getting sick, they are also less likely to spread the disease. When many people in a community have been vaccinated, their immunity against a disease even protects the small number of people in the group who cannot be vaccinated. This is called “community immunity”, also known as ‘community immunity’. 

Relying on others in your community being vaccinated puts you at greater risk of getting sick and, for many diseases, does not work at all. When diseases that are present in our environment do not need humans to spread, or when they have many different strains, they can infect unvaccinated individuals regardless of how many people around them were vaccinated 

Community immunity is not a replacement for vaccination. By choosing not to vaccinate, people put themselves at higher risk and can make it more likely a disease will circulate in their community.

Vaccines help protect people from diseases. Vaccines teach the body to defend itself against infections that make you sick.  

Most vaccines only contain a small part of a virus or bacterium to train the immune system, and others contain a killed version. These vaccines cannot make you sick themselves. 

However, so-called live attenuated vaccines contain a weakened version of a disease-causing virus or microorganism. These can – in rare cases – cause mild illness in people who have a weakened immune system due to illness or medical treatments. If your immune system is weakened, it is important that you discuss the pros and cons of getting a vaccine with your doctor.