COVID-19 vaccination does work in people with impaired immunity (immunocompromised patients), but is sometimes less effective. Vaccination is important for these people in particular, because COVID-19 may pose an additional risk to them. In some severely immunocompromised patients, two vaccinations are not sufficient. They have not developed enough immunity after two doses. In these cases, a third vaccination may boost their immune response.

Questions about a 3rd vaccination for people with impaired immunity

Many people with impaired immunity (‘immunocompromised patients’) are sufficiently protected after receiving two COVID-19 vaccinations. However, there are patients in some specific groups who have not built up sufficient antibodies against COVID-19 after two vaccinations. This has been demonstrated by scientific research. These people may not be well protected against COVID-19. For that reason, medical specialists have advised giving these patient groups a third vaccination. It is expected that some of these patients will be sufficiently protected after that third vaccination. 

This involves 200,000–400,000 patients with severely impaired immunity, aged 12 years and older, who are being treated by a medical specialist and are in one or more of the following groups:

  • Patients who have had an organ transplant; 
  • Patients who have had a bone marrow or stem cell transplant (autologous or allogeneic)*;
  • Patients who are currently receiving or have recently received treatment for a malignant haematological disorder, including CAR-T cell therapy*; 
  • All patients with a haematological malignancy which is known to be associated with severe immune deficiency (e.g. chronic lymphocytic leukaemia, multiple myeloma, Waldenström macroglobulinaemia)*; 
  • All cancer patients (solid tumours) who received chemotherapy and/or immune checkpoint inhibitors less than 3 months before their COVID-19 vaccinations;
  • All kidney patients, who are being monitored by a specialist, with eGFR <30ml/min^1.73m2 on immunosuppressants;
  • All dialysis patients; 
  • Individuals who have primary immune deficiency whose specialist has indicated the need for a third vaccination**; 
  • Patients who are being treated with the following immunosuppressants: 
    • B-cell depleting medication: anti-CD20 therapy, such as rituximab, ocrelizumab; 
    • strongly lymphopaenia-inducing medication: fingolimod (or similar S1P agonists),
    • cyclophosphamide (both pulse therapy and high-dose oral); 
    • mycophenolate mofetil in combination with long-term use of one or more other immunosuppressants

* If patients are currently being treated for this, or have received such treatment in the past two years.

**According to defined list of indications provided by the Dutch Society for Internal Medicine (NIV).

Some of these people will develop effective protection against COVID-19 after the third vaccination. In others, the immune response will still be less than optimal, and it will still be impossible to achieve effective protection against COVID-19. It is not possible to predict precisely who will experience this. 

That is why it is still necessary to maintain the coronavirus measures and to vaccinate individuals aged 12 years and older in the household, even after the third vaccination. This at least reduces the risk of infection.

Medical specialists have seen in studies of immunocompromised patients that many patients do have a sufficient immune response to the vaccinations. That means that reasonable or good protection against COVID-19 can be expected and a third vaccination is not necessary. These patients will therefore not receive an invitation for the third vaccination. The third vaccination is only offered to patients for whom the medical specialists believe, or know, that they are insufficiently protected after the previous two vaccinations.

The vaccination is registered in CoronIT by the Municipal Public Health Services (GGDs) and can be found on Nothing changes for the vaccination certificate: if a person already has a valid vaccination certificate, it will remain valid. The third vaccination is not required for a valid vaccination certificate.

The people who are eligible will receive an invitation from the hospital starting in October. Not everyone will receive an invitation right away; the letters will be spread out. The hospitals will send the invitation to their patients over the course of several weeks.

If you are eligible for a third vaccination, and only then, you will receive an invitation from the hospital. The invitation contains a special telephone number to call and make an appointment to be vaccinated. The vaccination will take place at a vaccination site operated by the Municipal Public Health Services (GGDs), and with an mRNA vaccine (Pfizer or Moderna).

You can only make an appointment if you receive an invitation. The invitation letter contains a special telephone number that you can call. After making the appointment, you will receive an email confirming the appointment with a link to the health statement. The health statement must be completed in advance.

! It is important to bring your invitation with you to the appointment. Without the invitation, you cannot be vaccinated!

The third vaccination for this group of people consists of a single dose of an mRNA vaccine (Pfizer or Moderna). You cannot choose a specific brand; you will receive what is available at that time at the Municipal Public Health Service (GGD) site. That means you will either get a vaccine of the same brand as the one you were vaccinated with before, or you will get a vaccine of a different brand. In any case, it will always be an mRNA vaccine.

The third vaccination can potentially cause the same side-effects as you may have had after the first or second dose of vaccine.

No, that is not necessary. You will be invited by your medical specialist because you have a specific disease or are receiving treatment. The selection for a third vaccination is not made on the basis of a laboratory result. In addition, it is not yet possible to reliably measure whether you have built up sufficient immunity. There are tests being used that determine whether you have antibodies against the coronavirus SARS-CoV-2, but it is still unclear what value these self-tests have, and what the minimum result would have to be for protection against a severe course of COVID-19 in the event of an infection.

A third vaccination can ensure that people who are insufficiently protected after two vaccinations still achieve better protection (‘building up an immune response’). For these people, this third vaccination is considered an additional part of the primary course of vaccinations, which consists of 1 or 2 vaccinations for most other people.

This is not the same as a booster vaccination. A booster gives an extra ‘boost’ to the immune system. It is intended is for people who initially built up sufficient protection after one or two vaccinations, but whose protection waned over time after that. The Health Council of the Netherlands will review whether a booster vaccination is needed later on.

Questions about vaccination in people with impaired immunity

A weakened immune system may result from various causes: due to treatment with drugs that suppress the immune system (immunosuppressants: medication used to treat autoimmune disorders), after an organ transplant, due to bone marrow disease, during cancer treatment, or sometimes as a result of an immune disorder that was present from birth or developed later (immunodeficiency).

For people with impaired immunity, even if they are under 60, COVID-19 poses the same elevated risk level as for older patients. The risk is not the same for the different groups of patients, since it depends heavily on the extent to which an individual’s immune system has been suppressed.

 Yes, but in some specific groups of people with severely impaired immunity, it sometimes works less well. Not every patient is the same, and there are differences between patients in terms of how much protection the vaccines offer. This is also known from previous research into the effectiveness of other vaccines in immunocompromised patients. Studies are taking place in which blood samples are examined to measure how the immune system responds to the vaccine. Research will have to determine whether immunocompromised patients could still get COVID-19 after vaccination, and whether the infection could still cause complications. In the meantime, several groups of patients have been identified for whom an additional third vaccination is recommended.

answer Do I need to have a blood test to check if I am protected after vaccination?

No, that is not yet relevant, since we unfortunately do not know what levels of antibodies or immune cells would be needed to achieve protection. Data on that topic is expected to become available in the next few months. At that point, it will be possible to determine more precisely whether the vaccinations offer sufficient protection. In future, it could be used to determine whether treatment is needed if infection does occur.

No, there is no reason to do so at this time. The results of a test to check your antibody levels do not clearly indicate how effectively you are protected. If a patient wants to do an antibody test, then it should preferably be arranged through the physician treating the patient in hospital. This ensures that the test results will be noted in the patient’s hospital records. The physician can then compare those test results to future information about required antibody levels. 

It means that the vaccine did induce your immune system to produce antibodies. We do not know yet if the antibody levels are high enough to provide effective, long-term protection against the virus or the complications from an infection. In any case, you should talk to your specialist about what the results mean for you. Patients should still follow the coronavirus rules, regardless of a test result.   


It means that the vaccine did not cause the immune system to generate enough antibodies. Negative could mean no antibodies at all, or not enough to detect with that test. It is possible that you are not protected against COVID-19. Talk to your specialist about what the results mean in your case.  Patients should still follow the coronavirus rules, regardless of a test result.

The immune system can handle vaccination just fine. There is no reason not to get vaccinated. As a result of your illness or medication, two vaccinations may not be effective enough. How strong your immune response is depends on the illness, which medications (immunosuppressants) are used, or how many different medications you are taking at the same time. It does not depend on an exhausted immune system. A negative antibody test after receiving a COVID-19 vaccine does not mean that your immune system does not work at all. And a positive antibody test after receiving a COVID-19 vaccine does not mean that your immune system is working effectively enough to prevent severe COVID-19.

Yes. People who have impaired immunity may not have the same protection after a previous infection, compared to others. For that reason, it is better to get fully vaccinated, even if you already had COVID-19. Most adults receive a single vaccination after having previously had COVID-19. People with impaired immunity are advised to get two vaccinations, to achieve optimal protection resulting from vaccination.