After three years of the Covid-19 pandemic, and in a winter with virtually all restrictions lifted, worldwide, there was an exponential growth in flu cases in various parts of the globe, including in Portugal.
The effects were felt in hospital services, with more people complaining of more severe symptoms or more severe flu cases than usual. Chris Smith, doctor, virologist and professor at the University of Cambridge, in the United Kingdom, recalls that, in the country, at Christmas time, the laboratory recorded that one in four samples collected from the population tested positive for the flu, far above what would be considered “a normal year.
“It was a contrast with the two previous flu seasons, when we had few or no cases, and this year we have a graph that looks like Everest”, points the expert to the Telegraph.
The most serious phase seems to have already passed, both for the flu and for Covid-19, which also registered an increase in cases in the festive season, but the real picture of what the pandemic isolation did to the population’s immunity in the face of respiratory viruses. It also illustrates well the explanation of why even those who this year escaped the flu, perhaps did not escape a brave cold, perhaps the strongest you have ever had.
“The flu is like our canary in a coal mine. It is one of the diseases that we monitor and measure closely, to keep up with the pace at which the virus is evolving. Thus, a huge increase in flu cases also points to a large increase in other diseases that we can catch similar, respiratory viruses such as influenza, coronavirus and rhinovirus, which are highly infectious and cause debilitating colds”, explains the specialist.
At the same time, with the return of normality to day-to-day life, when we go to the cinema, to the shops, we take public transport or we go to an event, we are once again encountering old ‘viral enemies’ that the organism fights and defeats, resulting in an immune reinforcement, for this and other agents that we may encounter.
The same goes for the flu. Even if you think you didn’t have it, because you didn’t have particularly severe symptoms, you may have had a mild infection, attenuated by a “well trained” immune system or previous contact with the virus.
When Covid-19 led to confinement and isolation, the spread of other viruses and infections was stopped, so the body was no longer so exposed to these agents and, therefore, losing ‘training’.
“Now we’ve developed some level of immune amnesia for some of the infections we’ve spent a lifetime learning to fight,” points out Chris Smith.
The consequence of this “immune deficit” is now that diseases that our body used to fight without any problem, now prove to be more difficult and produce more intense symptoms.
“Several relentless infections, mild or with some symptoms, will lead to what we think is the same cough or cold for several weeks. Some people will even think they have long-term Covid, even if that is not the case ”, clarifies the expert.
Thus, the most felt effects of viruses and respiratory infections are due to the ‘reeducation’ and ‘relearning’ of the body to deal with agents it is no longer used to, so that it can neutralize them again more easily.