Issue 31, 16 September 2021

The newsletter on COVID-19 vaccination is an RIVM publication with up-to-date information for professionals involved in COVID-19 vaccination.

Progress report on the COVID-19 vaccination campaign

From this week on, the RIVM weekly vaccination update will include people who had one jab after previously having COVID-19 in vaccination coverage for full vaccination.

Advisory reports of the Health Council: No booster

On 14 September 2021, the Health Council of the Netherlands issued its opinion on the COVID-19 booster vaccination. 

A booster vaccination against COVID-19, as an extra boost supplementing the primary course of vaccination, is not currently needed for the Dutch population. Research data shows that protection against infection offered by some COVID-19 vaccines has waned somewhat over time, but protection against serious illness has not decreased. Protection against serious illness is still at the same high level, and that also applies to the Delta variant. The vaccines offer 95% protection against hospital admission and 97% against ICU admission. 

The Health Council expects that booster vaccination will eventually be necessary for some groups. RIVM constantly keeps a close eye on vaccine effectiveness in the Netherlands and in other countries. If the protection provided by COVID-19 vaccination diminishes, the Municipal Public Health Services (GGDs) and RIVM are prepared to launch a booster campaign. 

Third vaccination for patients with severely impaired immunity

A specific subgroup of patients with severely impaired immunity may achieve more effective protection against the coronavirus with a third vaccination. These are patients who are being treated by a medical specialist for a specific condition or course of treatment. 

It is important to note that many people with impaired immunity are sufficiently protected after receiving two COVID-19 vaccinations. However, within several groups of patients with severely impaired immunity, there are some people who may not be effectively protected against COVID-19 after two vaccinations. Some of these patients can achieve better protection after a third vaccination. From October on, this specific group of people will receive an invitation from their medical specialist to receive a third vaccination. They can then make an appointment with the Municipal Public Health Service (GGD) for their third vaccination.

This involves about 200,000–400,000 patients, aged 12 years and older, who are being treated by a medical specialist in the context of one or more of the following health conditions, medications or treatments: 

  • 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 patients who have a solid tumour who received chemotherapy and/or immune checkpoint inhibitors less than 3 months before their COVID-19 vaccinations (if the dates are not available, then treatment after 1 January 2021 should be used);
  • 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 (according to a defined list with indications provided by the Dutch Society for Internal Medicine);
  • 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 one or more other immunosuppressants. 

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

In a working group, RIVM asked medical specialists about which groups would achieve more effective protection against COVID-19 as a result of a third vaccination. These medical specialists treat patients with severely impaired immunity. Their advisory opinion is based on results from medical research to date.  Research results show that some groups of patients with severely impaired immunity do not produce sufficient antibodies against COVID-19 after a first and second vaccination. It is expected that some of these people will be able to produce sufficient antibodies after a third vaccination. 

More information is available on the page on immunocompromised patients.

Difference between third vaccination and booster

The third vaccination can ensure that some people who are insufficiently protected after two vaccinations can still achieve better protection after the third jab (‘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, and is intended is for people who initially built up sufficient protection after one or two vaccinations, but whose protection waned after that (diminishing over time). The Health Council of the Netherlands issued an advisory report on that topic on 14 September. 

FAQ about vaccines and people with severely impaired immunity 

Ministerial decree on vaccination strategy

The Minister has adopted the Health Council’s advisory report on the booster vaccination and the advisory opinion of FMS and RIVM regarding the third vaccination.  See the Parliamentary letter on the current situation regarding COVID-19 (September 2021).

Vaccinations for people who had an allergic reaction after the first jab

Within the implementation of the vaccination strategy, a separate route was established earlier this year to vaccinate people at risk for an allergic reaction under the supervision of an allergist in the hospital. This is currently possible at six hospitals. Due to the high number of referrals, the Dutch Society for Allergology and Clinical Immunology (NVvAKI) has requested that additional vaccines be made available and additional capacity be organised at hospitals. The Minister intends to start expanding capacity as soon as possible so that this group (approximately 8,500 people waiting) can also receive their second vaccination quickly. The guidelines have been updated accordingly.

European Medicines Agency (EMA)

The Pharmacovigilance Risk Assessment Committee (PRAC) of the European Medicines Agency (EMA) is currently assessing whether there is a possible relationship between multisystem inflammatory syndrome (MIS) and COVID-19 vaccination. MIS is a very rare and serious health condition accompanied by fever and inflammation that can affect many parts of the body. PRAC is also reviewing data on cases of venous thromboembolism (blood clots in the veins) after vaccination with the Janssen vaccine.

Frequently asked questions

Can the second dose in a primary series be administered using a different type of vaccine than for the first dose (heterologous vaccination)?

In a two-dose series, it is preferable to administer the same type of vaccine for both doses (homologous). This is because research results on the effectiveness and side-effects of these vaccines are available, and have been registered (see the package leaflets for each vaccine). If more research results become available, this may change, providing options for heterologous vaccination. This is already the case for a two-dose series involving a dose of the AstraZeneca vaccine followed by a dose of Comirnaty; see the guidelines for more details.

No results are available at this time regarding effectiveness and side-effects of a two-dose series involving one dose each of both mRNA vaccines (Comirnaty and Moderna). No research results have been published for other combinations. Once results are available, the information will be incorporated into the guidelines.

Homologous vaccination is therefore preferable. If this is not possible for logistical reasons or would cause a delay, it is preferable to avoid delay and proceed with heterologous vaccination.

Updated implementation guidelines for COVID-19 vaccination

The implementation guidelines for COVID-19 vaccination 2021 have been updated. The latest version of the implementation guidelines is always available online (in Dutch). Section 1.3 outlines all major changes compared to the previous version; more minor interim changes are listed under Version Management (at the end of the document). The major changes primarily address the third dose and the route in the event of allergies. The other changes involve minor edits.

The new version of the COVID-19 vaccination handbook for immunocompromised patients was published on 15 September 2021.

Adverse reactions

Pharmacovigilance Centre Lareb has posted a new update about reports of possible adverse events following immunisation with COVID-19 vaccines which were reviewed by experts up to and including 12 September 2021.

Upcoming events

  • Wednesday, 22 September 2021, 20:00-21:15: webinar for healthcare professionals on the background of the COVID-19 booster vaccination, ethical dilemmas regarding COVID-19 vaccination, and the COVID-19 infection risk during pregnancy ( click here for more information and to register for the webinar). Please note that the webinar is exclusively in Dutch.
COVID-19 dilemma's 22 september 2021


Editors: Vaccination implementation, National Coordination Centre for Communicable Diseases Control (LCI).

For questions and/or comments about this newsletter, healthcare professionals can send a message to

Private citizens can call the public information number 0800 - 1351 with their questions.