We know that children are more contagious as they grow older. In general, the younger the children, the less significant the role they play in spreading the coronavirus SARS-CoV-2. Children do probably transmit the new variants, such as the UK variant, somewhat faster and more frequently. How much faster and more frequently? We do not know enough about this yet. To find out more, RIVM is researching how the virus spreads at primary schools. 

Much like adults, children of all ages can infect each other more easily if they spend extended periods of time in close proximity. This is often the case when children are at home, and it also applies when children are in a classroom at a primary school. We will therefore be researching how the virus spreads in the classroom and at school. To do so, we will monitor classes where a child or school employee has tested positive for COVID-19. After a coronavirus infection has been confirmed in a class, we will investigate how many other children and employees have been infected. We will also ask whether they have any symptoms and if so, which ones.

Why this study?

The knowledge resulting from this study will provide additional information on the role of children in the spread of the coronavirus SARS-CoV-2 and show whether specific measures could limit in-school transmission even more. The study also aims to determine the percentages of children with symptoms (symptomatic) and children without symptoms (asymptomatic) in infections within a primary school class. 

Who is participating in the study?

RIVM is cooperating in this study with the Municipal Public Health Services (GGDs) of Brabant-Zuidoost and the Utrecht region. Together with these GGDs, we ask beforehand if primary schools and umbrella organisations in these regions would like to participate in the study.  The school board will receive an information letter about participation. If the school takes part in the study, then the employees, parents and children will receive an online information package about the study which will be made available through the school, including an online consent form to formalise their participation in the study. Participating in the study is not mandatory.

How is the research conducted? 

The investigation starts when a child or an employee at the school tests positive for COVID-19 in the GGD test lanes. The children from the same class and all employees at the school who have consented to take part in the study then receive an invitation from the GGD by email or phone to be tested as well. They are tested twice: as soon as possible after the classmate or employee receives the positive test result, and on day 5 after the last contact with the classmate or employee. When they are tested, the parents and employees also receive an online survey asking if they had any symptoms, and if so, which ones and when the symptoms started. 

Testing takes place in the GGD test lanes, using a nose and throat swab. (Watch a video about testing children, as explained by children.) The participants in the study will receive their test results from the GGD via email. For research purposes, RIVM would like to receive the test results. This will make it possible for us to determine how many other children and employees have been infected, and how many people have symptoms. For the study, we ask the participants for their consent for the GGD to share the test results with RIVM. The data cannot be traced directly to a person. In addition, we ask the participants' permission for RIVM to request the nose and throat sample from the laboratory where it was tested.

Extra test

We would like to schedule a third test on day 28 after the classmate or employee tested positive for COVID-19. We will be consulting each school separately to ask if they are willing to take part in that final test. This third test would take place at the school itself, in a separate room. For that test, children and employees can take a saliva sample themselves. The RIVM research team will help, assisted by registered nurses. This third test enables us to check for antibodies against the coronavirus in saliva. We will ask the participants to take a new online survey at that time as well. The participants will also receive the results of this third test from RIVM. However, we can only provide them after the end of the study. It could take some time to receive these extra test results.

Overview of the tests


Nose and throat swab



Day 1 (GGD test lane)




Day 5 (GGD test lane)




Optional: day 28 (at school)




Questions or more information

If you have any questions or need more information about the research please contact us by email:  covid19-basisschool@rivm.nl.

Frequently asked questions

It is asking me for my COVID-19 Appointment Number. Where do I find that?

Your appointment number is stated in the confirmation email for your test appointment, below the bar code at the top of the email.  

Can the survey answers and test results be traced back to a person?

We will delete the COVID-19 Test Appointment Number after we have linked the survey data to the test result data. From that point on, the data cannot be traced directly to a person. 

What if the school wants to participate, but an employee or parent does not?

That is not a problem. Participating in the study is voluntary, so every parent and employee can decide for themselves. You are NOT required to participate if your school decides to take part in the study.