The corona figures seem fairly favourable, but there are caveats to that picture. The holidays reduce the number of positive tests and, by extension, hospital admissions.
But the holiday period will soon be over and then a reverse seasonal effect could occur. The cabinet is therefore maintaining most of the corona measures. Except in higher education. And there they will be abolished sooner than the OMT advises.
The NOS spoke about this with Jaap van Dissel, director of the Center for Infectious Disease Control (CIb) of the RIVM and Susan van den Hof, head of Epidemiology and surveillance of infectious diseases there.
The OMT wanted to let go of the 1.5 meters in MBO and higher education on 20 September. The cabinet does it three weeks earlier. Why this difference?
Jaap van Dissel: “That difference arises from a slightly different estimate of how far you are with vaccination and the two weeks after that to build up antibodies. The cabinet actually looks at the moment when people could make vaccination appointments, we at the time when the agreements have actually been made.”
The cabinet wants to release the 1.5 meters everywhere on the same 20 September. What does the OMT say about this?
Van Dissel: “The virus circulation depends on a number of factors, for example how many people return from a foreign holiday with an infection, whether they are tested and if they are positive go into isolation. We are now also seeing a leveling off in the decline in the virus. number of positive tests. That creates so many uncertainties that it was not possible to model that.”
Susan van den Hof: “The R-value has increased a bit but was still below 1 on July 29. That means that the epidemic became smaller. We will just have to see what will happen after the holiday period.”
The cabinet announces that there will be more relaxation on September 20 and then on November 1. The OMT may give advice on this by then.
Van Dissel: “We assess whether it is possible. If the cabinet makes a different assessment than we advise, this will become clear, as is now partly the case. We advise on the basis of epidemiology. I understand that the cabinet wants perspective That was put down during the press conference. The OMT will advise at that time whether it is possible on the dates mentioned.”
Another topic, what influence will the seasonal effect have in the coming period?
Van Dissel: “In this phase we have a favorable seasonal effect that helps to combat the epidemic. In the autumn that disappears, then everything you do against the coronavirus helps a little less, just as it contributes more now. “This is about 10 to 15 percent. That seasonal effect always plays a role and it makes the situation a bit more or less critical.”
“For example, in the last fourth wave, you saw a meteoric increase followed by a fairly rapid decrease that now seems to have stagnated a bit. We have yet to see where exactly that ends. The main measures we took because of that increase were looking at the source – and contact research and into the places where the spread mainly took place.”
“It mainly concerned young people who became infected and in particular in the night catering industry. The measures were aimed against this. Furthermore, only the opening hours of the normal catering industry are slightly limited. The reason for this rapid increase was removed by the closure of the The result was a rapid decrease and little spread of the virus from those young people to other groups. Where that did happen, 85 to 90 percent of the cases involved unvaccinated people. Vaccination helps. Things might have turned out differently in the autumn, because then we would have had the seasonal effect against us and the OMT might have advised more measures.”
Did the number of positive tests increase at the beginning of the summer, especially in areas with a low vaccination coverage?
Van den Hof: “The night catering was the hotspot, the spread was among young people and only limited among older groups. We do not now see that it has increased much more in the Bible Belt than elsewhere. It was an explosion of infections across the country. Young people come from all over and that partying happened all over the country. The spread that occurred in the immediate vicinity of the young people, parents, colleagues, but because it was so short-lived, no additional spread occurred in areas with a lower vaccination coverage.”
In the 121st OMT Advice Did you advise the cabinet to wait until mid-September to adjust the rules around holidays, when everyone has had the chance to be vaccinated. That didn’t happen.
Van Dissel: “That advice was mainly inspired by last year’s knowledge: knowing what happened with holidays and especially among groups of young people. So you have to keep an eye on the influx of possible cases and prevent them from spreading. Through testing and isolation after a positive test you hope to prevent it from going the same way as last year.”
“Ultimately, the circulation of the virus within the Netherlands, plus what is added by the holidaymakers, determines the autumn. You want to limit the import of the virus as much as possible, hence the test advice. In any case, you want to improve the situation in the autumn. “You want to know who comes back from abroad with an infection and that those people go into isolation.”
The share of holidaymakers in the total number of positive tests increases weekly, to 12 percent last week. Does that number worry you?
Van den Hof: “No, more and more people are returning from vacation, so it is logical that a growing proportion of people who have tested positive have been abroad. That will increase even further. You also really want them to feel at home. We know exactly what proportion of the positives has been abroad, but we do not know that about people who tested negative. The positive tests are mainly from young people, who we know have the most contacts. also be.”
It is unknown how many people do not get tested after returning from vacation.
Van den Hof: “If the spread increases enormously, we will see those people in the general figures about the virus spread and in source and contact research.”
Van Dissel: “You can see from the reports about tourists who are in a quarantine hotel somewhere, because they tested positive before they took the plane, that things are really different than a year ago. Very annoying for those involved, but it shows that such measures have an effect.”
There are many reports that gate checks at airports and borders are not really watertight.
Van Dissel: “It would of course be good for virus control if we have a complete picture. That is also what we advise, but that must be translated into a feasible policy. After all, we also know that approximately half of the people with complaints do not have themselves tested. “You always miss a part, but you can include that in calculations. With every infectious disease, the setting in which it occurs and human behavior have a major influence.”
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