Some people in the Netherlands have already been vaccinated against COVID‑19 (the disease caused by the coronavirus). But not everybody has been. A lot of people are therefore facing an important decision: should they get vaccinated or not? There are a lot of different opinions about this in the newspapers, on radio and TV, and on social media. But what does science have to say? In this leaflet, we – medical scientists from the Royal Netherlands Academy of Arts and Sciences (KNAW) – explain why we are getting vaccinated. 

You can use this information to help you decide about getting vaccinated. It’s also a good idea to talk to your family and friends about it. They may also be wondering whether or not to get vaccinated.

How does vaccination work?

Building up immunity without getting sick

When you get infected by a bacterium or virus, it takes a while before your immune system gets going to fight it. Once that’s happened, your body usually manages to clear up the infection completely and you get better on your own. But with some diseases it’s much harder for the body to fight the infection by itself. Some examples are measles, whooping cough, and polio. But we can do something about that. What helps with those kinds of dangerous diseases is to make the body prepared for fighting the infection. We do that by getting vaccinated, in other words having ourselves inoculated with a vaccine. 

By getting vaccinated, we make sure that the body is already “armed” for fighting a real infection. When someone gets the vaccine, they may have a slight fever/high temperature or a headache, or the arm where they had the injection may be a bit sore for about a day. That’s just enough to make the immune system go fully into action, as it would if there were an actual infection. Within a few weeks after vaccination, we are protected against the infection. That’s how it works with measles, whooping cough, and polio. These and other serious diseases have practically disappeared, because medical researchers have succeeded in developing effective vaccines against them, and because almost all children are inoculated with those vaccines nowadays. 

Vaccines have wiped out diseases

This graph shows how vaccination has helped wipe out a disease like polio in the Netherlands. Between 1994 and 2019, no more cases of polio were reported at all. That’s thanks to the polio vaccination programme that started in 1957. Since then, almost all parents have had their children vaccinated.

Long-term protection by vaccination

The protection provided by a vaccine usually lasts for a very long time, and with some of them it’s even for the rest of your life. Sometimes, though, you need to get vaccinated again. After the second or sometimes third injection, the protection is much stronger than after the first injection. Unfortunately, it’s not always possible to produce a vaccine. Despite a lot of research, effective vaccines have still not been developed against infectious diseases such as AIDS and malaria.


Start of vaccination programme

Annual reports of polio in the Netherlands before and after the start of the vaccination programme in 1957.

COVID-19 under control

It’s not always possible to produce a vaccine. Despite a lot of research, effective vaccines have still not been developed against infectious diseases such as AIDS and malaria. But vaccines have been developed to fight COVID-19, the disease caused by the coronavirus. We’ll soon be able to get that disease under control, just like we managed to do with measles, whooping cough, and polio. Suitable vaccines have been available in the Netherlands since early January. And they also seem to be effective against the new variants of the coronavirus that we are dealing with.

Better protection if we all get vaccinated

It’s important to know that vaccines against COVID-19 will only be truly successful if enough of us get vaccinated, as happens with other dangerous diseases. It’s actually very simple. If no one can catch a certain disease any more, then no one can transmit it to other people any more either. So in the end, the disease will disappear altogether.

How safe are vaccines?

Their safety has been extensively tested

It’s true that vaccines can have side effects. But they are only allowed to be used if they have first been extensively tested for safety by independent organisations. The vaccines that are now available against COVID 19 generally cause few or no side effects. We know that from scientific research involving tens of thousands of people. Specialists from all over Europe have checked that research very carefully. A vaccine is only approved for use if it’s been shown to protect us effectively and if there are no dangerous side effects.

Very rare side effects are only discovered when very large groups of people have received the vaccine. This is closely monitored worldwide, with experts then checking carefully whether there is perhaps a link between the vaccination and the side effect. If that is the case, they consider the risk of the rare side effect and whether some people are more at risk. This may lead to changes in vaccination policy. The authorities adopt a cautious approach here, even though the risk of becoming seriously ill from COVID 19 is much greater than the risk of harm to someone’s health from a rare side effect of being vaccinated.

Vaccines developed fast but carefully

The vaccines against COVID‑19 have been developed fast. They had to be, otherwise the harm caused by the disease would be much greater. Before the COVID-19 pandemic started, researchers were already developing vaccines against other viruses. They have now used the knowledge they gained from that work for the COVID-19 vaccines. No matter how fast these new vaccines were developed, they are still safe. Everything was done during the research to develop them in the same way as for other new drugs and vaccines. Every study that’s been done has shown that the COVID-19 vaccines are safe. So “fast” doesn’t mean “too fast”!

Why should you get vaccinated? 

If we get vaccinated with an approved vaccine, we aren’t only protecting ourselves. We’re also protecting one another, because it’s likely that after being vaccinated we will no longer be able to infect our family, friends, and colleagues. That’s not just an opinion in the discussion on vaccination. It’s the conclusion reached by the top scientific experts in the Netherlands and other countries. That’s why we – medical scientists from the Royal Netherlands Academy of Arts and Sciences (KNAW) – are getting vaccinated against COVID‑19. How about you? 

Do you want more information?

Reliable, detailed information about vaccination against COVID‑19 can be found on the Dutch government’s special website. 

Useful information on vaccination in general can be found here:

Watch the video about vaccination against COVID‑19 on the website of the Universiteit van Nederland (University of the Netherlands). 

In an online talk show, experts from the Dutch National Institute for Public Health and the Environment (RIVM) answer questions from people at home about vaccination and the coronavirus.

About this leaflet

This leaflet was written by medical scientists from the Royal Netherlands Academy of Arts and Sciences (KNAW). Academy members are among the top scientists in their field. The authors of this leaflet are not themselves directly involved in development of COVID‑19 vaccines or in testing them, but they are very familiar with the rules that vaccines must meet before their use can be authorised. Based on their trust in those rules and their knowledge of the science, they express their confidence in the authorised COVID‑19 vaccines and have personally chosen to be vaccinated with them.