The Omicron variant of the coronavirus SARS-CoV-2 is advancing in the Netherlands. The Omicron variant is expected to become the dominant SARS-CoV-2 variant in the Netherlands before the end of the year. Because the rapid spread of this variant will lead to more infections in the next few weeks, the number of hospital admissions will also start rising again. This increase could potentially significantly exceed care capacity. The new measures that took effect last Sunday, 19 December, are intended to help minimise the expected additional pressure on the healthcare system as a result of the Omicron variant.

Prevent the spread of the virus and help to prevent more hospital admissions by following the basic measures, even if you are vaccinated and even if you have had a booster vaccination.   

All the weekly COVID-19 figures are presented in a table and in graphs on the RIVM website.

Hospital admissions and ICU admissions

The number of people with COVID-19 who were admitted to hospital decreased by 33% last week compared to the week before, dropping to 1,335 new hospital admissions. 248 patients with COVID-19 were admitted to ICU last week, 90 fewer new patients than in the week before (-27%). The downward trend in hospital admissions is an effect of the measures that started on 28 November. Due to the extended treatment period required for COVID-19 patients, pressure on hospitals remains very high. 

Positive COVID-19 tests 

94,864 positive test results were reported last week* (19% fewer than the week before that). 380,533 people were tested by the Municipal Public Health Services (GGDs), 16% fewer than in the week before that. Per 100,000 inhabitants, 544 people received a positive test result, with the highest number of infections per 100,000 reported in Zuid-Holland-Zuid (649) and the lowest in Twente (436). All age groups showed a decrease in the number of reported positive tests (Figure 1). The highest number of reported positive tests per 100,000 inhabitants continues to be among children of primary school age.
 

Figure 1: Number of reported positive tests per 100,000 inhabitants, by age group (8 November to 19 December 2021).

Vaccination and previous infection provide less effective protection against Omicron infection

The primary course of COVID-19 vaccinations and a previous infection with the coronavirus SARS-CoV-2 are significantly less effective in preventing infection with the Omicron variant of the virus than infection with the Delta variant. These findings are from recent research conducted by RIVM. Jaap van Dissel explained this on 21 December during his technical briefing to the House of Representatives of the Netherlands (page 12). Following a booster vaccination, there is a clear increase in protection against infection with the Omicron variant. In the next few weeks, it will also become apparent whether the risk of serious illness differs between the Omicron and Delta variants. RIVM is tracking incidence of the Omicron variant in the Netherlands, for example in the national pathogen surveillance, with data updates every Friday. 

Reproduction numbers

The most recent reproduction number based on positive COVID-19 tests is for 6 December, and was 0.88 (lower limit 0.87 – upper limit 0.89). That means that 100 people who had COVID-19 on 6 December will collectively infect another 88 new people. On 6 December, the spread of the virus was still slowly. The reproduction number is expected to rise again in the next few weeks as the Omicron variant spreads.

* Positive tests reported to RIVM between 14 December 2021 at 10:01 and 21 December 2021 at 10:00. The number of tests in GGD test lanes, hospital admissions and ICU admissions are shown by calendar week.