We are learning more and more about the coronavirus SARS-CoV-2 and the disease COVID-19, caused by the virus. On this page, you will find answers to frequently asked questions (FAQ) and everything we know about the coronavirus so far.

Frequently asked questions COVID-19

Can I still get COVID-19 after booster vaccination?

Booster vaccination offers 68% protection against infection and 92% against hospital admission after an infection involving the Omicron variant of the coronavirus SARS-CoV-2. You can still get COVID-19, but the booster vaccination reduces the risk that you will feel poorly or become seriously ill. Read more about booster vaccination.

What are the recommendations for people in risk groups to minimise the risk of infection with the coronavirus SARS-CoV-2?

The government is gradually relaxing the coronavirus measures, and many measures are being discontinued completely. Additional recommendations to prevent infection with the coronavirus SARS-CoV-2 are applicable to people at higher risk of serious illness due to COVID-19. Read more about risk groups and COVID-19.

What is the difference between quarantine and isolation?

It may not be completely clear to many people, but there is an important difference between isolation and quarantine. Isolation and quarantine are also subject to different rules. You always go into isolation if you test positive, which means that it has been confirmed that you have COVID-19. This will prevent you from infecting others. A quarantine recommendation is not effective at this time, but that could change if the number of infections starts rising rapidly again. If that happens, you will go into quarantine if you have been in contact with someone who has COVID-19, and therefore might be infected yourself, but are not sure yet. This is a precaution to ensure that you do not continue to spread the virus, if you do turn out to be infected.

Why has the isolation period been shortened?

Someone who has the Omicron variant of the coronavirus SARS-CoV-2 may already be contagious before they start showing symptoms, but the contagious period is shorter than for previous variants of the virus. For that reason, the isolation rules have been adjusted slightly as of 18 February 2022. 
People who have tested positive for COVID-19 and are in isolation may leave isolation if they have not had any symptoms for 24 hours and it has been at least five days since the symptoms started. Previously, it had to be at least 7 days since the symptoms started. 
Your situation determines whether you have to go into quarantine, and for how long. This also applies to how long the isolation period lasts. 
For more information, see the page on quarantine and isolation.


I have COVID-19. Can the GGD see which variant I have? 

No, the Municipal Public Health Services (GGDs) cannot see which coronavirus variant you have based on the results of a PCR test or antigen test. And it is not necessary to know which variant you are infected with in order to treat COVID-19. 

To determine which coronavirus variant you have, further investigation is required, known as sequencing. Sequencing involves laboratory analysis to take a closer look at the building blocks of the virus. This is based on further investigation of the virus sample that was taken with a cotton swab in the nose and throat. By looking at how the virus is constructed, it is possible to recognise characteristic ‘building blocks’ of a variant. 

Sequencing is performed on random samples in the context of national research on pathogen surveillance. This laboratory research is more complicated than the analysis to determine whether or not you have COVID-19. By analysing randomly selected samples, it is possible to accurately estimate how a variant is spreading.

Why can people now use a self-test if they have symptoms?

Recent research showed that COVID-19 self-tests work well in people who have symptoms. For that reason, both options are now available: people who have symptoms can now get tested by the GGD or use a self-test. Testing if you have symptoms is now easier, and we hope that this will help even more people to test for COVID-19 as soon as they have any symptoms. More testing means finding more infections and controlling the spread. Read more about self-testing.

Why do I have to get tested by the GGD to confirm a positive result on a self-test?

If you test positive for COVID-19 on a self-test, it is important to also be tested by the GGD (a confirmation test). This is because there is a slight chance of a false positive on a self-test. In most cases, a confirmation test by the GGD confirms the result of the self-test. Confirmation by the GGD also makes it possible to initiate source and contact tracing and helps RIVM maintain an overview of how the virus is spreading.  Also, if you test positive for COVID-19 based on a GGD test, you will be able to get a certificate of recovery, which will allow you to obtain a coronavirus entry pass, or extend the validity of your current entry pass. Read more about self-testing.

What do we know about the Omicron variant?

The first cases involving the Omicron variant (B.1.1.529) of the coronavirus SARS-CoV-2 were reported in South Africa at the end of November 2021. The percentage of cases involving the Omicron variant is rising rapidly around the world, including in the Netherlands. The rapid spread of the Omicron variant may lead to a high peak in hospital and ICU admissions – a peak that could significantly exceed care capacity. To prevent this, the Outbreak Management Team (OMT) recommended expanding the evening lockdown on 17 December 2021. By now, the Omicron variant is spreading so fast that it will probably become the most common and dominant variant in the Netherlands before the end of the year. Similar to other variants, the small changes (mutations) in this new variant are seen mainly in the lines bristling out from the coronavirus: the spike protein. A striking feature of this variant is that it has an unusually large number of mutations in the spike protein. That includes a number of mutations at locations that alter the properties of the virus.

Initial research shows that vaccine effectiveness against infection without booster vaccination is considerably lower compared to the Delta variant. People can get the Omicron variant of the virus, even if they have had the coronavirus before or have already been vaccinated. Protection against infection with the Omicron variant increases significantly after a booster jab. It is not yet known whether the virus variant also causes people to become more seriously ill from a coronavirus infection.

The Omicron variant is detected by the PCR tests used in the Netherlands for COVID-19 testing. However, like the Alpha variant, the Omicron variant produces a non-standard result on a special PCR test based on detecting the presence of the spike protein. This test is not generally used in diagnostics in the Netherlands. However, this special test may be used to track the Omicron variant in pathogen surveillance. The Omicron variant has been designated as a Variant of Concern by WHO and ECDC.

Read more about the  variants of the coronavirus SARS-CoV-2

What role do children in the age groups at primary school level currently play in spreading the virus?  

In the week of 16-23 November 2021, the highest number of positive tests was recorded in the age group of 7-11 years. This is not the age group in which the current wave of infections started. However, children in this age group have been involved in outbreaks and clusters more frequently since the autumn holidays. This is probably partly because children under 12 are not vaccinated. Also, they have frequent contact with each other without restrictions, such as staying 1.5 metres apart. It is very important for everyone, including children at the primary school level, to stay home and get tested if they have symptoms, and to go into quarantine if a household member or other close contact tests positive for COVID-19. RIVM is keeping a close eye on the situation regarding schoolchildren to see how children contribute to spreading the virus among other age groups.

Read more about children, school and COVID-19.

Now that there are many people who have COVID-19, are additional measures needed to slow the spread of the virus? If so, why is that?

By working together, we can make it through the winter without very strict and drastic measures. The basic measures are the most important factor here. If people do not comply with the measures, or follow them less carefully, infection rates will rise. If that happens, additional measures will be needed to slow the spread of the virus. In some other European countries, people are following the basic measures more carefully, so additional measures are less necessary.

Additional measures aim to reduce the number of contacts between people. The virus can spread from one person to another during every contact. The fewer contacts people have, especially close contacts, the less the virus will be able to keep spreading.

Read more about the spread of the virus

How is RIVM keeping track of the virus now that there are so many infections and the test lanes are filling up?

We have an overall impression of how the virus is spreading in the Netherlands. However, the reported number of people who test positive for COVID-19 is no longer an accurate indicator. The actual number is generally higher, partly because there are always people who do not get tested. Hospital admissions and ICU admissions provide a more accurate overview, but those figures are three weeks behind the current infections. Someone who tests positive now may – in the worst-case scenario – become seriously ill a few weeks from now, and only then be admitted to hospital or ICU. RIVM also derives a great deal of data from coronavirus monitoring in sewage. We do have some idea of what is happening with the virus, but the level of accuracy varies in different phases of the pandemic.

Does the vaccination offer sufficient protection against the Delta variant?

The Delta variant is currently circulating in the Netherlands. This variant is more contagious than the Alpha variant of the coronavirus SARS-CoV-2. However, vaccination still offers effective protection against all the variants, including the Delta variant. Vaccination is somewhat less effective in very elderly people. But the short answer is: yes, vaccination works.

Is a vaccinated person less likely to get infected?  

There is a difference between infection and illness. If you are exposed to the virus, it may be present somewhere in your body, such as your throat. Viral exposure could lead to a breakthrough infection that causes symptoms. But that may not happen. Your immune system may recognise the virus and clear it from your body before you become ill.  If you do develop a breakthrough infection, you may become ill. A vaccinated person who has been exposed to the virus is 50% less likely to become ill than someone who is unvaccinated or partly vaccinated. The risk of infection is reduced by about half.

Read more about vaccine effectiveness

Will antiviral pills to treat COVID-19 help us end the pandemic?

Vaccination will help us prevent the coronavirus SARS-CoV-2 from spreading. The antiviral pills to treat COVID-19 may offer a supplementary option.  The European Medicines Agency (EMA) is reviewing data on these pills. If they receive EMA approval, the question is how widely these medicines can be used. It is a good development to look forward to. We do not yet know whether infection will be considered very concerning once these pills are available; that will depend on how well the medicines work. Initially, oral antiviral treatment will need to be combined with other strategies.

How long after vaccination are you protected against COVID-19?

Most people receive 2 vaccinations for effective protection. After the second vaccination, you are well protected 1 week later (if you received the Pfizer vaccine) or 2 weeks later (if you received the Moderna or AstraZeneca vaccine). Sometimes 1 vaccination is enough. This applies if you are vaccinated with the Janssen vaccine. In that case, you are well protected 28 days after your vaccination. Or if you had COVID-19 within the past 6 months. In that case, you are well protected against the coronavirus SARS-CoV-2 two weeks after your vaccination.

Read more about COVID-19 vaccination.

Why does RIVM not share all its data, although conclusions based on that data are sometimes presented in news items?

RIVM uses data to carry out its mandated task of monitoring and controlling infectious diseases and conducting epidemiological research. Not all data used by RIVM can be published as open data. This depends on the agreements made about the purposes for which the data can be used. Sometimes traceability is an important reason for not sharing data. By combining certain information, including public information, it is sometimes possible for medical data and other information to be traced back to an individual.

Examples include hospital data for people who are admitted to hospital with COVID-19, and data on whether or not they are vaccinated. RIVM does publish general information on these figures, but does not share the underlying data. Why not? Suppose you know that your neighbour has been admitted to hospital due to his COVID-19 symptoms. By linking data on the age distribution of hospitalised patients in a municipality and the vaccination status of hospitalised patients, it would be easy to figure out your neighbour’s vaccination status (especially if numbers are low). 

Why does RIVM only report national figures? Why are they not reporting figures for each hospital? 

Reporting figures at the national level provides the most accurate overview of vaccine effectiveness. Various factors are taken into account, such as age, type of vaccine, period of infection and time since vaccination. Privacy must be safeguarded. If the data is subdivided into different hospitals, that would result in publication of a smaller data set, so data could potentially be traced back to individual patients. This would make it impossible to safeguard patient privacy. 
Moreover, the figures for one hospital may not accurately reflect the number of infections in that region which resulted in hospital admission. For example, people are not always admitted to the hospital closest to their current location, and patients are sometimes transferred to a different hospital. Moreover, there may also be differences in patient population at each hospital, for example when comparing a university hospital or top-ranking clinical facility to a regional hospital. This distorts vaccine effectiveness figures at the hospital level.  

Why are the figures from the RIVM updates different from the figures reported by hospitals? 

The current situation in each hospital may seem to deviate from the national figures, because the national information focuses on new hospital admissions (incidence). The figures for each hospital or region represent the total number of people that are currently in hospital (prevalence). COVID-19 patients are usually hospitalised for some time: at least a week on average if they are only admitted to a nursing ward, and 2.5 weeks in the ICU. As a result, the data based on incidence is different from the data based on prevalence.

Why is it that changes in the percentage of vaccinated people in hospital admissions do not necessarily indicate that vaccine effectiveness is changing? 

Vaccine effectiveness is calculated by very precisely measuring vaccination coverage in the general population based on age and calendar date. These calculations also take into account the type of vaccine that people received and the time since vaccination. Changes in the percentage of vaccinated patients in hospital admissions could also caused by changes in vaccination coverage in the population, or changes in the age distribution, type of vaccine, or time since vaccination among the patients admitted to hospital. These changes do not necessarily mean that the effectiveness of the vaccine has changed. Therefore, these factors are taken into account in vaccine effectiveness reporting.

Why is it important for me to cooperate with source and contact tracing?

By cooperating with source and contact tracing by the Municipal Public Health Services (GGDs), you are helping to prevent the further spread of the coronavirus. Read more about source and contact tracing on the page testing for COVID-19

What do we know about the variants (mutations) of the coronavirus SARS-CoV-2?

Many variants of the coronavirus SARS-CoV-2 are circulating worldwide. The World Health Organization (WHO) and the European Centre for Disease Control (ECDC) determine which are considered Variants of Concern and which are Variants of Interest. RIVM follows those recommendations. We monitor these variants and map their presence due to their (potential) high-risk characteristics and degree of spread. Through the national Pathogen Surveillance, we are also monitoring the coronavirus variants present in the Netherlands. Read more about the virus variants in the Netherlands

What is Long COVID?

Some people have long-term symptoms after a SARS-CoV-2 infection. This is referred to as ‘Long COVID’ or ‘PASC’: Post-Acute Sequelae of SARS-CoV-2. These symptoms may persist for several weeks after COVID-19, but could sometimes last several months. Read more about Long COVID.

I have hay fever or allergies. Can I go outside or go to work?

In principle, yes. If you have hay fever, you have the same symptoms every year at about the same time. You will be able to recognise the normal symptoms of hay fever. The same applies to symptoms that you usually get if you are allergic to something. If there is any doubt, or if the symptoms feel different, get tested and stay home until you get the results.

Is any research being done on the role of viral spread among and by children in this pandemic?

Initiated by RIVM, various studies are being conducted on the role that children play in the spread of the coronavirus SARS-CoV-2.  You can read more about this on the page about children, school and COVID-19. In general, the younger the children, the less significant the role they play in spreading the virus. This applies to the original virus variant and to the more contagious virus variants. However, the more contagious variants involve more transmission of the virus in all age groups, compared to the old variants. Read more about children and the virus.

How important is ventilation in preventing the spread of the virus?

Good ventilation is very important. Good ventilation is necessary for a healthy and pleasant indoor climate. It also helps to limit transmission of respiratory infections, such as COVID-19. When you are indoors with other people, it is important to ventilate the room well.  Read more about ventilation.

When am I a close contact of someone who has COVID-19, and therefore need to go into quarantine?

  • If you were less than 1.5 metres apart from someone with COVID-19 for longer than 15 minutes
  • If someone with COVID-19 coughs or sneezes in your face, or if you had direct contact such as hugging or kissing
  • A household member could also be a close contact. However, the rules for those contacts are different than for other close contacts.

How do I find out if I am a close contact of someone who has COVID-19?

  • If the person with COVID-19 notifies you that they are infected
  • If the Municipal Public Health Service (GGD) contacts you
  • If you have installed the CoronaMelder app, you could be notified by the app.

What should I do if I am a close contact of someone who has COVID-19?

That depends on whether or not you are protected against COVID-19. For example, you are protected if you are fully vaccinated, or if you have previously had COVID-19. 
Read more on the page about quarantine and isolation.

When do I have to stay home if I have symptoms?

Stay home and get tested if you have one or more of the following symptoms that could indicate COVID-19. This applies even if you do not feel very ill.
Symptoms may include a nasal cold, runny nose, sneezing, sore throat, coughing, shortness of breath, elevated temperature or fever, or sudden loss of smell and/or taste (without nasal congestion). Some people with COVID-19 have also reported other symptoms.

Read more about the symptoms on the page about coronavirus disease (COVID-19).

When am I contagious if I have the coronavirus SARS-CoV-2?

You may already be contagious in the two days before you start showing symptoms. People with COVID-19 are generally contagious for about 1 or 2 weeks after the first symptoms. 

Read more about the spread of COVID-19

Are pregnant women more likely to become infected with the coronavirus SARS-CoV-2? 

Generally, the effects of COVID-19 in a healthy pregnant woman do not appear to be any different (for the child and the mother) than for other respiratory infections that can lead to fever and pneumonia. Pregnant women do have an increased chance of being admitted to hospital or ICU. 

Read more about pregnancy and COVID-19

How does RIVM handle results from new research (in the Netherlands and internationally)?

RIVM closely follows international publications on research studies. If new insights emerge from Dutch and international research results, RIVM will adapt its recommendations and guidelines accordingly. 

Read more about COVID-19 research