10 Feb 2024 at 05:26
More pneumonia, a flu epidemic, more whooping cough and stomach flu: we’re sniffling and coughing like crazy. This is not only because it is that time of year, but also because our immune system needs to get reacquainted with these viruses after corona.
“Our immune system is not worse, but it has been put to work less during the corona pandemic,” emphasizes Margreet te Wierik. She is a doctor at the National Coordination of Infectious Disease Control of the RIVM.
“And now we are seeing a catch-up: many people are now coming into contact with a virus or bacteria for the first time and are therefore becoming ill.” Mariette Hooiveld of health organization Nivel also agrees. “People who did not experience certain infectious diseases during the lockdown often still get them. But that says nothing about a weakened immune system.”
What about then? During the pandemic we saw each other less, we kept our distance and we washed our hands several times a day. “As a result, we saw that many bacteria and viruses, including flu, whooping cough and norovirus (stomach flu), were almost completely gone.” They could not spread well through contaminated hands, coughing and sneezing and people sitting close to each other.
The number of pneumonias among children is decreasing, but is still much higher than in previous years. Photo: Nivel
Our immune system does not yet know how to tackle viruses
We usually get sick when we come into contact with an infected person for the first time or after a longer period of time. “From that moment on, our immune system recognizes the pathogen and if we come into contact with an infected person again within a short time, we will not become ill again from the same virus or bacteria,” Te Wierik explains.
“But during the lockdown we came into contact with viruses and bacteria much less, so our immune system did not learn to ‘tackle’ those viruses.” Immunity to a number of infections has therefore decreased, says virologist Marion Koopmans.
We call this the “immunity gap”, says immunologist Geert van den Boogaart of the University of Groningen. “That is a theory based on the idea that our immune system must be constantly stimulated to maintain our immunity. Due to social distancing, we have actually lost that a bit.”
After the corona rules were lifted, we simply got sick again
During the pandemic we saw a “gigantic rebound” of flu and other diseases, says Van den Boogaart. “Then we thought of a positive side effect, but that turned out to be wrong. Because of mutations in the flu virus, we simply became ill again after the measures were lifted.”
We started traveling more and visiting more people. But to become infected, many people have to see each other. In addition, it takes time for the flu to reach a large number of people, says Van den Boogaart. We now see those numbers reflected in the figures.
But I already had the flu, so why do I still get sick?
“This is because viruses mutate,” Van den Boogaart explains. This means that the virus actually looks a little different every time, so the immune system does not recognize it and you can therefore become ill again. This mutation happens when a lot of people have the flu.
During the corona measures, the flu virus had less chance to mutate, because we did not get the flu. Yet there is now another new flu virus that our immune system does not recognize. “That mutation may have arisen in a country where they did not take social distancing so seriously,” the immunologist thinks.
Children in particular ensure wide spread
The wide spread of the flu virus, among other things, is mainly among children, says the immunologist. “They have not built up good resistance during the pandemic and are now spreading viruses more quickly.”
There is evidence for this, especially with streptococcus A. This is a bacterial infection that causes strep throat. “Normally, the immune system ‘remembers’ this bacteria, but children did not come into contact with it during corona.”
Koopmans sees that too. “Many infections are most common in children. They transmit them to adults. Now viruses are catching up and you will therefore also see this in adults,” she believes.
To prevent yourself from getting sick, you should still adhere to the corona measures to some extent. “We have learned that it works,” says Te Wierik. “So keep your distance from sick or coughing people and cough and sneeze into your elbow.”
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2024-02-10 04:26:51
#Sick #immune #system #reacquainted #viruses #pandemic #NU.nl
