At least 1,100 people were infected with Covid-19 after a festival in the Netherlands earlier this month, which shows exactly why Belgium made the right choice in holding off on big events, according to virologist and interfederal Covid-19 spokesperson Steven Van Gucht.
After the entire Dutch nightlife sector was allowed to open at the end of June, at least 1,100 people tested positive after attending the two-day techno festival 'Verknipt', even though it used entry tests to prevent large-scale infections.
"The Netherlands went too fast. Belgium made the right choice in waiting," Van Gucht told The Brussels Times.
Through contact tracing, the Utrecht branch of the Dutch health service GGD concluded most of the infections were caused by some 130 visitors who were already infected before they entered the festival grounds. It also pointed to the excessively long period of validity of the rapid tests, which was 40 hours at the time, as a possible cause.
"This proves what we have always said: a negative test is no guarantee. In itself, it is not a warrant that suddenly makes all risks go away," Van Gucht stressed.
While testing is a very useful tool to prevent some of the virus spread, and definitely has its place in the strategy to make sure that large-scale events can take place again, not all infections can be stopped.
"The idea that with a negative test you can drop all other measures is a false one," he said. "You have to see it like a Swiss cheese with many holes: you need several layers on top of each other to control the risks as much as possible."
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A test is only a snapshot, which tells you something about whether or not you are infectious today, but it has little value the day after, according to Van Gucht.
The best prevention is and remains vaccination, he said.
"Vaccination is something you carry with you all the time. You have antibodies and immunity, and you carry that with you all the time," Van Gucht explained.
Additionally, it provides double protection: if everyone at an event is vaccinated, then on the one hand there is a reduced chance of being infected, and on the other hand the chance of infecting someone else is reduced should that other person still come into contact with the virus.
"Those are barriers that work all the time. That is what we need," he said, comparing it against a negative test result which only tells someone they are not infectious at the time of the test.
The cautious, Belgian way
Belgium is opting for a gradual approach, whereby the country gradually starts to step up the pace. "That is because we are following the rhythm of the vaccinations, which is the most important thing," Van Gucht said.
The advantage of that approach is that the number of people allowed at events is increased only gradually, instead of allowed everything at once as the Netherlands did.
"Opening up gradually also means that we also know that, by then, we will have many more people who are fully protected," Van Gucht said.
There will be some who are not (yet) vaccinated, which is why testing remains necessary, but the risk does decrease because the proportion of people who are not yet protected is getting smaller and smaller.
"The Netherlands has taught the rest of the world - and certainly Belgium - some good lessons, because this is one of the reasons why politicians in the Consultative Committee decided to shorten the period of validity of those tests," he said.
"It was not just about fraud with test certificates that were distributed in the Netherlands, it was also simply that the period of the test validity was too long," Van Gucht said.
The Consultative Committee reduced the validity of a negative PCR test result for events from 72 hours to 48 hours, and for an antigen test, the initial validity of 48 hours was reduced to just 24 hours.
"However, even with a shorter validity period, you have to realise that such a test does not eliminate all risks," he said. "If there are many unvaccinated people walking around at such an event, then you have an ideal scenario for super-spreading."
While there is always the possibility of a so-called 'breakthrough infection' (getting infected even after being fully vaccinated), virus circulation will not be so bad if everyone has been vaccinated.
"If the virus circulates within a vaccinated population, the consequences are very limited," Van Gucht said. "On the one hand, you have the fact that you are protected against serious disease, and on the other hand, those breakthrough infections are going to circulate a lot less easily."
The real problem is when the virus gets to those who are not yet vaccinated, according to him.
"If that is half of your festival area (which would be the case for the Pukkelpop music festival, which mainly targets younger people and teenagers), a breakthrough infection becomes an issue, because you can give the virus to people who are not vaccinated, and they might get very sick and even end up in hospital."
Learning from others
While Belgium will only start organising test events from this weekend, the Netherlands, by contrast, not only started too soon, but also created a whole series of super spreader events.
"The Dutch example shows that it is not always so much the size of the event, but also the sequence of them," Van Gucht said.
"Young people often go from one event to another: one day they go out here, the next they go somewhere else, creating a kind of chain," he explained.
Following the test event in Utrecht, contact research showed that 90% of the infected festival-goers that were questioned had visited other venues earlier that week, likely without knowing they were infected.
"In that way, a small event eventually becomes a really big one, because it is a succession of smaller ones," Van Gucht said. "You have to take that into account as well."
"However, the biggest lesson we should learn from the Netherlands is to keep the validity period of your test short," he added, stressing that he believes Belgium has understood the message.
Currently, experts in Belgium and Europe are looking towards England, which went through with its "Freedom Day" even while the coronavirus cases in the country were rising.
"I think we have to look very carefully at what is going to happen there next, and what that means for their hospitals and deaths," Van Gucht said.
"They are taking a gamble, let's be clear about that. It is an experiment with their public health," he added. "It is risky for them, but very interesting for us."
According to Van Gucht, the fact that Belgium is currently situated in the middle of the pack in terms of infections and restrictions is "a luxury."
"There is no need to be overly strict, because that is not necessary, but we are also not the country leading the others and taking the risks," he said.
"We have to look closely at other countries and learn the necessary lessons from them," Van Gucht said. "Like with the Netherlands, we can learn from their mistakes."