Coronadashboard data explained
- Coronadashboard data explained

Coronavirus variants

Where do the numbers come from?

The numbers on coronavirus variants are supplied by the National Institute for Public Health and the Environment (RIVM) as open data.

How are the numbers calculated?

The National Institute for Public Health and the Environment (RIVM) has been studying coronavirus variants in the Netherlands through pathogen surveillance since late 2020.

On the basis of this analysis, RIVM can determine what percentage of infections each variant is responsible for and, from there, predict the speed at which the different variants are likely to spread. This enables RIVM to estimate what percentage of future infections will be caused by which variant. As new data arrives each week, it is checked against these predictions. This helps make future predictions more and more reliable. The figures shown on the Dashboard are not RIVM’s predictions, but rather the data from the pathogen surveillance. Preparing and analysing the samples and processing the data takes time. The figures for the most recent weeks are therefore incomplete and, because of this, we do not show them on the Dashboard. As a result, the percentage for a given variant as reported by RIVM often differs from what is shown on the Dashboard at that time. The media also tends to report RIVM’s predictions.

Figures may change from week to week compared to what was previously published, generally as a result of changes to the date a sample was collected or other changes related to the sample in the registration system. Data from the most recent weeks is incomplete and is updated in future publications as more information becomes available. In other words, the data on the dashboard is updated retroactively.

Variants on the dashboard
The table on the dashboard shows the variants of concern and the variants of interest. The European Centre for Disease Prevention and Control (ECDC) and the World Health Organization (WHO) consider a variant to be a variant of concern if it spreads more easily, makes people more sick or if vaccines are less effective against the variant. A variant of interest is a variant that has been traced to multiple infections in a particular setting or cluster, or that has been detected in multiple countries.

The graph on the dashboard only shows the ECDC variants of concern. These variants are monitored because of their potential risk. RIVM follows the ECDC and the WHO guidelines in this respect. The variants that are not shown separately in the graph are listed in the category 'other variants'.

EG.5 (a subvariant of XBB.1.9)

On August 9, 2023, the World Health Organization (WHO) upgraded the omikron subvariant EG.5 (a subvariant of XBB.1.9) from a "variant under monitoring" (VUM) to a "variant of interest" (VOI). This was done because of the properties of EG.5 to possibly grow into a dominant variant.
EG.5 is also found in the Netherlands and its share is increasing. These are small numbers now. There is currently no evidence that this subvariant causes more severe disease than previous omikron variants. According to the most recent WHO risk assessment, the risk of this variant is estimated to be "low". For more information about the coronavirus and variants, visit the RIVM website.

Distorted picture from week 21, 2023

From May 22, 2023 (week 21), too few measurements/samples have been received. Due to the low numbers of samples, the graphs may give a distorted and incomplete picture of the proportions of the variants from May 22 onwards. Variants may be missing and a variant shown may be too present, so that the distribution is no longer representative.

Adjustments in the graph Alpha variant

As of 3 September 2021 the European Centre for Disease Prevention and Control (ECDC) and the World Health Organization (WHO) are no longer designating the Alpha variant as a ‘variant of concern’, but as a ‘variant of interest’. Since that date, the National Institute for Public Health and the Environment (RIVM) has included data on the Alpha variant in the data set as a ‘variant of interest’. On the graph ‘Coronavirus variants over time’, variants of interests are included in the group ‘other coronavirus variants’. The Alpha variant was therefore not shown separately on the graph between 3 September and 28 October 2021.

However, because the Alpha variant was previously a ‘variant of concern’ and was the dominant variant for almost 6 months, an exemption has now been made for this variant. As of 28 October 2021 the Alpha variant is shown separately in the graph again.