Eugyppius suggests an interesting hypothesis about the disappearance of the remnants of the Spanish Flu and the advent of a new seasonal flu virus based on Corona
The flu is gone. This is not an illusion. It’s not down to the wilful or mistaken misdiagnosis of Corona or anything like that. Most countries have long-standing influenza surveillance programs, entire offices of people whose job it is to find and track the flu. These programs are still running, and influenza tests are still widely administered across the world. Despite all of this searching, nobody can find anything but a few outliers. As a seasonal phenomenon in the northern and southern hemispheres, influenza has disappeared….
A lot of basic matters are poorly understood in the field of virology, and one of them is why waves of infection seem to spontaneously collapse, rather than continuing indefinitely until all susceptible have been taken ill. One reason seems to be that some viruses interfere with other viruses, such that the rise of one compels the decline of another. Plainly, not all pathogens are at odds with each other. Co-infections are common among the overlapping deep-winter viruses. Some viruses, however, definitely seem to exclude others, at least some of the time and in certain places. Influenza and Corona are two of these mutually exclusive viruses. Since it has killed the flu, Corona can operate both in the vacant flu season and in its own natively preferred dark winter months.
Some months ago, I suggested that Corona’s victory over influenza could well represent a permanent change in the order of respiratory viruses – a revolution, perhaps a very rare one. The only conceivable historical precedent would be the Spanish Flu of 1918. While we have historical reports of influenza-like illness going back centuries, we don’t have any sequenced viruses predating the second wave of this great 1918 pandemic. Before 1918, we can’t be sure that seasonal flu-like illnesses were caused by influenza viruses at all. For all we know, coronaviruses were the dominant scourge prior to 1918, and their centuries-long reign was interrupted by the anomalous and highly destructive avian influenza that entered humans in that year. Perhaps the ensuing century of influenza was an unstable equilibrium, an anomaly, and Corona has restored a prior, more ordinary world.
All that’s speculation, but we do know that the ensuing seasonal flus for decades afterwards were descended, directly or indirectly, from that first 1918 strain. What happened in 1918 was certainly a viral revolution, on the order of the upset Corona achieved in 2019. Much of virology, as a field, grew up in the shadow of 1918, as an attempt to understand the pandemic of that year and the obviously related seasonal infections to which it gave birth.
I thought the reports of the flu vanishing were total nonsense, nothing more than a propagandistic attempt to report flu cases as cases of Covid-19. But if it’s true that the seasonal flu as we’ve known it for the past 100 years didn’t even exist before the Spanish Flu, then it’s conceivable that the coronavirus of 2019 has simply replaced it as the seasonal flu virus.
In which case, the flu vaccines are even more worthless than before, and worse, those vaccinated against Covid-19, whose immune systems have been trained to permit variants of the coronavirus to enter and wreak havoc without meeting much resistance, will likely face regular periodic episodes of new flu without enjoying the benefit of the usual reduction in severity.