Two years ago, when we went through our first pandemic winter, seasonal influenza did not appear. Not in Sweden nor anywhere else in the Northern Hemisphere. Something like this has never happened before. Measures to limit the spread of COVID-19 have completely suppressed the spread of influenza. Experts’ warnings about a “double pandemic,” a parallel spread of COVID-19 and influenza, are shamelessly crafted.
Until last year, the flu behaved unusually. During the fall, the number of cases increased and it appeared to be a normal, albeit somewhat early, season for influenza. But at the end of the year, the Omicron wave came in with tremendous force, and cases of influenza fell. When the spread of omicrons slowed in the spring, the flu returned for a second, but smaller wave.
How will it be this year? Nobody knows, but there is a cloud of concern that immunity in the population is low several years after infection with very little. If you look at Australia, which has just had its annual flu season, it can be tricky. The country has recorded the highest prevalence of influenza in several years, as well as a significant outbreak of the covid-19 virus.
Covid-19 is also a cloud of anxiety ahead of winter. Three years later, the coronavirus is still relatively unexpected. What will he bring now?
Experts seem to agree that the spread of infection will increase, and cases have already begun to increase in several European countries. It is also relatively high in Sweden, According to a new randomized examination from the Public Health Agency.
The increased spread of infection is due, among other things, to the fact that we spend more time indoors and that some respiratory viruses thrive especially during the cold period. Another reason for the increased spread of infection is reduced immunity. The protection you get after a vaccination or infection is not enough for any length of time, therefore a booster dose is recommended for vulnerable groups to reduce the risk of serious disease.
New viral variants have previously been behind the increase in infections. Now we have almost global dominance of omikron, the fifth variant of particular importance, for a year. Instead of completely new variants, omicron sub variants appeared. For example, BA.5 accounted for most cases in Sweden and many other countries for several months. But are there other sub-variables about to take over? Omicron relatives with spoof names such as BA.2.75.2, BQ.1.1, and BF.7 have been discovered, but we don’t know if any of them have the potential to offset BA.5. Nor what consequences it could have. But most people believe that both a previous infection and a vaccination prevent severe disease.
So much is uncertain before next winter. Perhaps it will be another winter with a mild flu season and there may not be a real winter wave of COVID-19, thanks to the high level of immunity in the population. But it could be the double pandemic that worries experts. The simultaneous or subsequent high prevalence of both COVID-19 and influenza hits the same groups hard: the elderly and people with underlying diseases. Therefore, it is important that those recommended are vaccinated against both influenza and covid-19.
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