Research into COVID-19 vaccination

In order to control the coronavirus pandemic, everybody who receives a COVID-19 vaccination must subsequently be optimally protected against the consequences of a COVID-19 infection. Policymakers and healthcare professionals therefore need more information about the effect of these vaccines. ZonMw has commissioned various studies into COVID-19 vaccination. These studies supplement the vaccination studies of the National Institute for Public Health and the Environment (RIVM), vaccine manufacturers and international researchers and organisations.

Contributing to the optimum use of COVID-19 vaccination

The studies about COVID-19 vaccination focus on generating knowledge that can be directly used for patients and by healthcare practitioners in the Netherlands. In addition, the studies contribute to decision-making about the optimal use of COVID-19 vaccines in the Netherlands.

Where possible, the studies are realised in collaboration with international initiatives so that maximum use can be made of each other's knowledge and results. The results from the studies will be shared with ZonMw on an interim basis. The Ministry of Health, Welfare and Sport, RIVM, and the Health Council of the Netherlands will also be involved in this.

Which studies into COVID-19 vaccination have been commissioned?

The studies that have been made possible via ZonMw concern:

  • Vaccination of people with a compromised immune system;
  • Vaccination of adults and children with long COVID;
  • Research into thrombosis and thrombocytopenia after SARS-CoV-2 vaccination;
  • Research into the effect of a Janssen vaccine (vector vaccine) or an mRNA vaccine (Moderna or Pfizer) in people who received a Janssen vaccine as the first vaccine;
  • Research into the combined vaccination against COVID-19 and influenza in people aged 60 years or over. For the COVID-19 vaccination, this concerns a booster vaccination.

Vaccination of people with a compromised immune system

At the initiative of ZonMw, 8 studies into the effect of Covid 19 vaccination in patients with immune disorders started at the beginning of 2021. For these patients and the health professionals treating them, it was not yet clear at that time whether the COVID-19 vaccines would protect the patients against the severe consequences of an infection. Normally, these patients with immune disorders do not respond well to vaccines. The first results are already known and demonstrate that a large group is protected after two vaccinations, and that a small group of patients with severe immune disorders benefits from a third vaccination.

> Read more about the research into COVID-19 vaccination in people with a compromised immune system

Coronavaccination and long COVID

Some people continue to experience symptoms after a COVID-19 infection, such as fatigue and a loss of smell and taste. This is also referred to as long COVID or persistent symptoms. What is the effect of COVID-19 vaccinations on people who have persistent symptoms following a COVID-19 infection? Research into this is being done in the RECoVERED study at Amsterdam UMC and in the VINCERE study at the Spaarne Gasthuis hospital in Haarlem. In the first study, a large group of COVID-19 patients are involved who have already been followed for a long period in an ongoing cohort study. In the second study, children with long COVID are involved.

> Project page long COVID and vaccination in the RECoVERED cohort

> Project page vaccination in children with long COVID to improve the fitness - VINCERE

Rare side effects thrombosis and/or thrombocytopenia after COVID-19 vaccination

Side effects can occur after receiving a COVID-19 vaccine. The most frequently occurring side effects are fever, headache and fatigue. These side effects are often brief and usually cause no harm.

In April 2021, it was established that in a few people, the rare side effect VIPIT (Vaccine-Induced Prothrombotic Immune Thrombocytopenia) might occur after COVID-19 vaccination. This side effect is also known as VITT (Vaccine-Induced Immune Thrombotic Thrombocytopenia) and it concerns a blood clot (thrombosis) combined with a lack of blood platelets (thrombopenia). Most of these patients then develop a thrombosis in the head (sinus thrombosis). In a study of Amsterdam UMC, research is currently being carried out into how often this occurs, what the symptoms are and how this could be treated.

> Project page thrombosis and thrombocytopenia after SARS-CoV-2 vaccination

Switching between a vector vaccine and mRNA vaccine in the case of a booster vaccination

In the SWITCH trial of Erasmus MC, research is being done into the effect of using the same (vector vaccine) and an mRNA vaccine after a Janssen vaccination (vector vaccine). In doing so, the researchers examine the occurrence of side effects. With this study, the researchers hope to gain more insight into which COVID-19 vaccines can be used as a booster. The first results have shown that an mRNA vaccine is the most effective after an initial Janssen vaccine.

The first results from this study are already known. These show that the administration of an mRNA vaccine is more effective compared to the administration of one or two Janssen vaccinations when people have received a vector vaccine as the first vaccine.

On 3 November 2022, the SWITCH consortium, under the leadership of Prof. Hugo van der Kuy received a Pearl award from ZonMw. You can view a video about the project below, or visit the Pearl page.


Onderzoek naar combineren coronavaccins

Combined vaccination against COVID-19 and the influenza virus

In the TACTIC study of Radboudumc, research is conducted into the combined vaccination against COVID-19 and the influenza virus among people aged 60 years and over. It may be necessary to offer vulnerable people lasting protection against COVID-19 by giving them a booster vaccination before the winter season. This is also the moment when this group receives the influenza vaccine. Researchers expect to gain a good idea as to how the coronavirus and influenza vaccinations can be given as safely as possible.

> Project page timing and sequence of vaccination against COVID-19 and influenza

Researchers in the spotlight


Blog series

In several blogs, researchers tell about their experiences conducting studies into corona vaccinations, and the urgency and importance of these studies.
podcast over covidvaccinaties


How did the 8 vaccination studies about people with an immune disorder come about? This podcast discusses the setup of these studies and the cooperation between ZonMw and the researchers.

Vaccine studies: part of a comprehensive coronavirus study

Together with researchers, patients, healthcare professionals, data professionals and international partners, ZonMw is working on possibilities to use research and knowledge to contribute to solutions in the fight against the coronavirus and COVID-19 and their impact on society, both now and in the future. The vaccine studies are also a part of this.

Do you have any questions about the studies? Please contact us via


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