Table 1 Phases of COVID-19 pandemic in the Netherlands from 2019–2021: duration and description

Phase 0

Week 1 (2019)

Week 8 (2020)

The pre-pandemic phase

-Before the outbreak of COVID-19 in the Netherlands

Phase 1

Week 9 (2020)

Week 22 (2020)

The first wave of the COVID-19 pandemic

-In week 9, the first positive COVID-19 case in the Netherlands was confirmed

-In week 11, the cabinet introduced some basic rules and some measures, such as keeping distance, no gatherings with over 100 people, work from home if possible

-In week 13 of 2020, the intelligent lockdown was introduced, everyone should stay home as much as possible, a maximum of 3 people for visit, and all gatherings were forbidden

Phase 2

Week 23 (2020)

Week 40 (2020)

The first relaxation phase

-Decrease in infection rates and relaxation of the measures

Phase 3

Week 41 (2020)

Week 3 (2021)

The second wave of the COVID-19 pandemic

-In week 42, a partial lockdown was introduced, which was reinforced in week 45

-In week 49, people could get tested without symptoms if they were in close contact with positive cases

-In week 51, full lockdown was introduced, which lasted until the end of phase 4

Phase 4

Week 4 (2021)

Week 16 (2021)

The second wave of the COVID-19 pandemic (alpha-variant)

-In phase 4 alpha variant was the dominant virus, which was more contagious and caused more hospitalizations than previous virus

Phase 5

Week 17 (2021)

Week 43 (2021)

The second relaxation phase

-Decrease in infection rates and relaxation of the measures

Phase 6

Week 44 (2021)

Week 52 (2021)

The third wave of the COVID-19 pandemic (delta variant)

-In week 44, the cabinet has implemented additional measures, such as mandating face mask mandatory in more places and requiring a coronavirus entry pass at more locations, to slow down the spread of the virus

- In week 50, the lockdown was introduced