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

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.


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.


What 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)  determines which are considered Variants of Concern and which are Variants of Interest. RIVMNational Institute for Public Health and the Environment 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


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