Vaccine-preventable diseases

1. Key messages

2. Epidemiology of some vaccine-preventable diseases

Success stories: no more polio and rubella in Belgium

Poliomyelitis is a highly infectious viral disease. It causes mild or no symptoms in most people, but in some people it can cause total paralysis or death. After the introduction of the polio vaccination in 1956, the incidence of polio sharply declined and cases have been rare following the introduction of mandatory vaccination in 1967. Since 2002, the European region has been considered polio-free by the World Health Organization (WHO). Currently, the risk of an epidemic in Belgium is low thanks to the high vaccination coverage. 

Similarly, Belgium was certified by WHO as having eliminated rubella, thanks to vaccination. This virus can have severe consequences during pregnancy leading to stillbirth, congenital malformations and congenital rubella syndrome (CRS). The last autochthonous case of CRS in Belgium dates from 2007 and the last imported case from 2012. However, as long as these viruses are still circulating elsewhere, vaccination and surveillance remain necessary due to the risk of importation. 

Disease outbreaks still occur due to immunisation gaps in the population

For most diseases targeted by vaccination, incidence has dropped drastically since the start of routine vaccination, but outbreaks still occur. Under-immunisation of certain groups or geographical regions significantly increases the risk of outbreaks. There was, for example, a diphtheria outbreak among asylum seekers in 2022, a group where vaccination remains difficult and coverage is too low [2]. 

In 2024, an important measles outbreak occurred, affecting mostly unvaccinated schoolchildren in Brussels. This highlights the importance of high vaccination coverage throughout the entire population.

Shifts in circulating serotypes of invasive infections slow down the success of vaccination campaigns

For invasive diseases like meningo- and pneumococcal disease, current vaccines protect against certain serogroups/serotypes, but not all. Since the introduction of these vaccines in Belgium, circulation of strains included in the vaccine has dropped significantly. However, other strains not covered by the vaccine in the schedule are on the rise. This changing epidemiology does not indicate a failure of the vaccination policy—total incidence remains lower than before vaccination programs were introduced. It does however highlight the need for development of new vaccines and adjustments in vaccination schedules. For example, the meningococcal vaccine was changed from MenC to MenACWY in 2023 to include three additional serogroups, after an increase in serogroups W and Y was observed.

3. Vaccination coverage

3.1. Vaccination coverage for children under 2 years old

Vaccination coverage in Belgium is high and stable over time

In Belgium, the 90% coverage threshold set out in the WHO's Global Vaccine Action Plan (GVAP) [3] has been reached for full primary vaccination (1-4 doses depending on the vaccine) for all vaccines included in the recommended basic vaccination schedule, except for the rotavirus vaccine. The rotavirus vaccine is the only one that is recommended for children but not provided in the free-of-charge vaccination program. 

Vaccination coverage for vaccines in the basic vaccination programs is comparable for all Belgian regions 

Vaccination coverage for vaccines in the basic vaccination programs for children is consistently high across all Belgian regions. National vaccination coverage for the full schedule (4 doses) of the hexavalent vaccine is 94%, with comparable coverage rates in all regions. The hexavalent vaccine is a vaccine that combines vaccination against six diseases in 1 shot (diphtheria-tetanus-pertussis (DTP), hepatitis B (HebB), Haemophilus Influenza type b (Hib), and poliomyelitis (polio)). Similarly, coverage for meningococcal (92%) and pneumococcal (94%) vaccines, as well as the first dose of measles-mumps-rubella (MMR1), show minimal regional differences. 

Rotavirus coverage is lower in Brussels and Wallonia

The rotavirus vaccine is recommended by the Superior Health Council (SHC) but is not included in the free vaccination programs by the regions. It is partially reimbursed by the RIZIV-INAMI, but you still have to pay about €7-12 per dose yourself. As a result, vaccination rates were lower than for the free vaccines in the basic vaccination program, especially in Brussels (70%) and Wallonia (81%). In Flanders, on the other hand, the vaccination coverage rate was 92%.

3.2. Vaccination coverage for adolescents

WHO targets for MMR and HPV vaccination coverage are not being met

The WHO targets of 95% for 2 documented doses of mumps, measles and rubella (MMR) and ≥ 90% for human papillomavirus (HPV) coverage have not been reached in Belgium. Based on the latest available surveys, the weighted national average coverage for MMR2 was 83% and has remained stable over time. 

The national coverage for full HPV vaccination (2 doses) is 72% for girls, 65% for boys and 68% for girls and boys together. HPV vaccination has slowly been increasing over the years for girls. In 2019, vaccination for boys was introduced. Coverage in boys is currently lagging behind that of girls. 

Important regional differences in coverage rates for adolescents 

Following the advice from the Superior Health Council to lower the age for the second dose of MMR2, the French Community (FWB) and German-speaking Community lowered the age to 7-8 years old and the Flemish Community to 9-10 years old. In Flanders, the latest survey was performed in 2020, reporting coverage of 89%. FWB performed a new coverage survey in 2021-2022 that indicated a 73% coverage in the whole French Community and 70% for Brussels specifically. There is a likely under-reporting of full vaccination (MMR1+2) due to lost or missing documentation for the first dose in all the regions.

For HPV, the weighted national average hides important regional differences. In 2019-2020, Flanders had a full HPV vaccination coverage rate of 81% for both girls and boys, while the French Community had a coverage of 48%. In a new survey by FWB in 2022-2023, coverage in the French Community increased to 52%. Coverage in Brussels specifically increased from 39% to 41%.

4. Read more

Background

Childhood immunization in Belgium

The Belgian Superior Health Council decides, on a scientific basis, about the recommended vaccination schedule for children. This schedule currently includes vaccines for thirteen infectious diseases. Of these, the polio vaccine is the only one that is mandatory in Belgium. The different communities (Flemish, French and German-speaking Community) are then responsible for the implementation of the guidelines and practical organization of the vaccination campaigns. As a result, there are some regional differences in the age of administration of certain vaccines for children (see schedules for Flanders and Fédération Wallonie-Bruxelles) and in the vaccine brands that are being used. Extensive information can be found in the report “Vaccination policy and advice in Belgium” (available in Dutch and French).

In Belgium, vaccination coverage is monitored by coverage surveys organized and financed by the relevant regions/communities. These surveys take place approximately every four to five years. An estimate of national vaccination coverage in Belgium is calculated each year by Sciensano's Epidemiology of Infectious Diseases Department on the basis of the most recent vaccine coverage studies and weighted by population size. To study infant vaccination coverage, the same methodology is used in all three regions, with a sample drawn from the general population. The method used to study adolescent vaccination coverage differs from region to region. In Flanders, adolescent vaccination coverage studies are carried out on a general population sample. In Brussels and Wallonia, vaccination coverage surveys have been carried out every year on a sample of pupils in French-speaking schools [4]. In Flanders, an electronic vaccination registry, Vaccinet, has existed since 2006 and is being routinely used by all vaccinators. For the French community, new vaccination registries are currently under development. In the future, registry-based vaccination coverage estimates might replace the periodical surveys. 

Epidemiological reports

More detailed information on the epidemiology and surveillance of vaccine-preventable diseases can be found in the yearly reports on the specific health topic pages on Sciensano website: 

• Poliomyelitis
• Diphtheria
• Tetanus
• Whooping cough
• Haemophilus influenza type b
• Hepatitis B
• Measles
• Mumps
• Rubella
• Neisseria meningitides
• Streptococcus pneumoniae
• Rotavirus
• HPV
• Influenza

Definitions

Immunization gaps

Localized communities with low vaccine uptake (e.g., specific demographic groups, geographical areas, hard-to-reach communities, etc.), increasing their susceptibility to infection and the likelihood of outbreaks. 

Serotypes/serogroups

Describes a way of grouping cells or microorganisms, such as bacteria, based on the antigens or other molecules found on their surfaces.

Vaccine coverage 

Percentage of persons who received certain vaccine doses. For example, coverage of DTP3 is the percentage of infants who received all three doses of diphtheria, tetanus and pertussis (DTP) vaccine.

Primary vaccination

The initial series of vaccinations given to an individual to achieve immunity against a particular disease, usually involving multiple doses administered (1-4 depending on the vaccine) over a specified period to build a strong and long-lasting immune response.

References

1. Sciensano. Samenvattend jaarverslag 2022. Brussel: Sciensano; 2023. https://www.sciensano.be/sites/default/files/samenvattend_jaarverslag_2022_nl.pdf
2. Jacquinet S, Martini H, Mangion J, Neusy S, Detollenaere A, Hammami N. Outbreak of Corynebacterium diphtheriae among asylum seekers in Belgium in 2022: operational challenges and lessons learnt. Euro Surveill. 2023;28(44). 
3. World Health Organization. Global vaccine action plan: monitoring, evaluation and accountability: secretariat annual report 2020. Geneva: World Health Organization; 2020. 24 p. https://iris.who.int/handle/10665/337433
4. Grammens T, Cornelissen L. sciensano.be. 2022. Couverture vaccinale des vaccinations de base. https://www.sciensano.be/nl/biblio/couverture-vaccinale-des-vaccinations-de-base
5. Maertens K, Willen L, Van Damme P, Roelants M, Guérin C, de Kroon M, et al. Studie van de vaccinatiegraad in Vlaanderen, 2020. [Internet]. Leuvens Universitair Vaccinologie Centrum, KUL, Leuven and Centrum voor de Evaluatie van Vaccinaties, UA, Antwerpen; https://www.laatjevaccineren.be/vaccinatiegraadstudie
6. Robert E, Swennen B, Coppieters Y. Enquête de couverture vaccinale des enfants de 18 à 24 en Fédération Wallonie-Bruxelles (Bruxelles excepté), 2019. Bruxelles: Ecole de Santé Publique, ULB; 2020. https://www.ccref.org/e-vax/EnqueteNourrissons2019-
7. Robert E, Swennen B, Coppieters Y. Enquête de couverture vaccinale des enfants de 18 à 24 mois en Région de Bruxelles-Capitale, 2019. Bruxelles: Ecole de Santé Publique, ULB; 2020.  https://www.ccref.org/e-vax/EnqueteNourrissons2019-
8. Brasseur C, Sarr K, Montoisy C. Résumé de l’enquête de couverture vaccinale 2021-2022. La vaccination contre la rougeole, la rubéole et les oreillons (RRO) chez les élèves de 6ème primaire dans l’enseignement de la Fédération Wallonie-Bruxelles. Bruxelles: FWB et ONE; 2022. https://www.ccref.org/e-vax/resume_enquete_couverture_vaccinale_2021-2022.pdf
9. Brasseur C, Sarr K. Résumé enquête de couverture vaccinale 2022-2023. La vaccination contre le papillomavirus humain (HPV) chez les élèves de 2ème secondaire dans l’enseignement de la Fédération Wallonie-Bruxelles. Bruxelles: FWB et ONE; 2023. https://www.ccref.org/e-vax/pdf/ECV_2022-2023_HPV_Resume.pdf
10. WHO & Unicef. WHO/UNICEF Estimates of National Immunization Coverage (WUENIC). 2023.  

Please cite this page as: Sciensano. Communicable Diseases: Vaccine-preventable diseases, Health Status Report, 18 March 2025, Brussels, Belgium, https://www.healthybelgium.be/en/health-status/communicable-diseases/vaccine preventable diseases