I did not receive an invitation. Can I still take part?

No, it is not possible to take part in the study now. You can only participate in the study if you already received an invitation. Potential participants could register until 13 October 2021. 


What is the difference between the PIENTER Corona Study and the Sanquin study?

Both the Sanquin national blood bank and the PIENTER Corona Study examine blood samples from participants for antibodies against the coronavirus SARS-CoV-2. The differences between these two research projects include the following:

  • Sanquin is examining blood from people between the ages of 18 and 79 years old. The PIENTER Corona participants range in age from 1 to 92 years old.
  • Sanquin is examining blood samples from blood donors. Blood donors are generally in good health. Participants in the PIENTER Corona Study are people randomly selected from the general Dutch population. This includes people in good health as well as people whose health is less than optimal.

Compared to the Sanquin study, the PIENTER Corona Study provides a better overview of the general Dutch population. Also, because the same people are monitored over time, the PIENTER Corona Study allows us to analyse the immunity built up during the epidemic and after vaccination. In addition, the PIENTER Corona Study maps out a more extensive inventory of possible risk factors and symptoms.


Are you also investigating whether people have been infected with the coronavirus SARS-CoV-2 a second time?

No, that is not part of the study. A participant in the PIENTER Corona Study is asked to send a blood sample several times over an extended period. Once a number of blood samples are available, changes in the levels of antibodies in the blood could possibly indicate that a participant has been in contact with the coronavirus SARS-CoV-2 a second time. However, in order to know for sure whether a participant has been infected on two separate occasions, it would be necessary to identify the virus by performing a coronavirus test. This is not what we are doing in the PIENTER Corona Study.

FAQ about how to log in

I have not received a login code yet. What should I do?

As of round 9 (November 2022), you can set your own password. Your mobile telephone number will be used to confirm the login. Your new password will remain valid for future rounds of the study. In the week that your fingerprick self-sampling set arrives by post, you will receive an email with instructions for creating a new password. (Please note: the message could end up in your spam folder or junk mail folder.) Once you create a password, you can use it to log in. Then you will receive a verification code by SMS. From then on, you can use your chosen password in combination with the SMS verification to log in.

If you do not receive an SMS with a verification code, it is possible that we do not have your mobile telephone number in our records. In that case, please contact us at PIENTERonderzoek@rivm.nl. Are you using a new email address or mobile telephone number? Let us know by sending us an email.


What should I do if I forgot my password?

As of round 9 (November 2022), you can set your own password. This password will remain valid for future rounds of the study. Your login details give you access to the portal. If you forget your password, you can request a new password here by clicking on > Forgot your password?. If you enter the email address that you gave us, then you will receive a message at that address containing a link to reset your password. The password reset link only works once. If you are using a new email address and have not yet sent it to us, please contact us at PIENTERonderzoek@rivm.nl.

Note: SMS verification will be used as a standard part of the login process from round 9 on. That means that we need to have a mobile telephone number where we can contact you. If we do not have your mobile telephone number, or if you have a new number and have not let us know yet, you will not receive a SMS verification code when you try to log in. In that case, please contact us via PIENTERonderzoek@rivm.nl.


I changed my password, but then my screen froze. What should I do?

This can happen if you are using a password manager. First close your internet browser, then switch off the password manager in your settings. Or you can use a separate window in Incognito or Privacy mode. Alternatively, you could use a different internet browser (Chrome, Safari, etc.).

FAQ about the questionnaire

 I am logged in, but I do not see a questionnaire

After you save the new password, you will be directed to the landing page of your personal portal. From the landing page, there are several ways to open the questionnaire:

After you save the new password, you will be directed to the landing page of your personal portal. From the landing page, there are several ways to open the questionnaire:

  1. In the landing page of the portal, you will see a blue/green area with the text: “Klik in dit vak om direct naar de vragenlijst te gaan.” (Click in this area to go directly to the questionnaire.) Click anywhere in that area to go directly to your questionnaire.
  2. In the menu on the left, click on the last option (‘Vragenlijst’).
Landingspage of portal Pienter Corona Study

That will take you to the following screen. The questionnaire for you (based on your age group) and the status of the questionnaire are displayed here. Click on the questionnaire to open it.

Questionnaire PIENTER Corona Study

No menu visible on the left?
Then zoom out to see the whole web page, or click on the 3 lines in the top left corner to display the menu: 

No menu visible on the left?

FAQ about the fingerprick blood sample

Why do you want me to send the blood within days of receiving the fingerprick self-sampling set?

Because we are researching a specific time period, it is important that as many people as possible participate within the shortest possible time frame. When we receive the fingerprick blood samples at RIVM, we do the laboratory analyses as soon as possible. That means we can also quickly link the results to the questionnaire data.


I will be on holiday or unavailable for several weeks and cannot take the blood sample right away. Should I still do it?

Yes, all the blood samples that come in are analysed. Once we have received most of the samples, we will perform the testing and analysis. Anything that comes in after that will be analysed later, and will also provide important information.


How much blood should be collected in the tube?

Try to fill the tube if you can. If that is not possible, at least try to collect 10-20 drops of blood in the tube.

Collect blood in collection tube

I am not able to get blood to come out of my finger. Any tips?

Improving blood flow

Before using the fingerprick set, it could help to soak your hand in warm water for a few minutes (or hold a glass of warm water), or to wave your arms around, or to move around, for example by walking up and down stairs. Then massage the finger. This improves the blood flow in your fingers, making it easier for you to collect (enough) blood from your finger.

How to collect the sample

The best sample site is the middle finger or ring finger on the hand that you do not use for writing. Pick a spot on the side of your fingertip for good blood flow.
After you have used the self-sample kit to prick your finger, press right next to the sample site to get the blood flowing. The finger that you sampled should be pointed downward. It can take a few moments for a drop of blood to appear; this is normal. It often helps to rub along your finger towards the fingertip. These and other instructions can also be found in the “Instructions for taking fingerprick blood samples” that you received with your self-sample set. A video explaining how to collect a fingerprick blood sample is also available above.


Will I receive an update on the results of my fingerprick blood sample?

Participants receive a personal update about the results of the blood tests after each round. From round 9 on, you can see the results in your portal (red arrow in the image below). Under the heading ‘Uitslagen’ (Results), you can view your personal results for all the rounds in which you were a participant. For additional explanation about what your personal results mean, go to the page explaining the results. If you fill out the questionnaire on paper, you will also receive your personal results of the blood test in a letter.

Uitslag is te vinden in linkermenu bij uitslagen

If no results are provided

Sometimes we are unable to test a blood sample for antibodies. When that happens, we are unable to provide a personal update on the results. In some cases, something went wrong while collecting the sample, or the blood sample was too small to test for antibodies. If that was the case, we will let you know.

Other questions

I have moved house. Should I notify the researchers?

We would appreciate it if you could give us your new address. We will then update your address details in our participant database so our correspondence is sent to your correct address. You can report your change of address via  PIENTERonderzoek@rivm.nl.


What about security?

The legal basis for the use of personal data is established in the General Data Protection Regulation (GDPR), which is implemented in national law in the Netherlands in the Dutch GDPR Implementation Act (Uitvoeringswet Algemene Verordening gegevensbescherming). The PIENTER Corona Study is in compliance with all GDPR guidelines. We are making every effort to safeguard your privacy. The envelope for sending us your fingerprick blood sample is designed especially for this purpose. Your blood will be sent safely.