SPIEGEL-TALK "Longing for the Pandemic"
Jefferson: It is true that influenza viruses are sometimes unpredictable. A certain amount of caution is therefore called for. Nevertheless, I find it crazy what disasters are predicted for us year after year by the influenza experts. These prophecies get worse and worse. Yet none of them has ever come true. For example, what happened to the bird flu that was supposed to kill us all? Nothing. But these people still go on and on with their predictions. Sometimes it seems to me that some people are just longing for a pandemic.
Jefferson: I’m just skewering the false certainty that we’re being led to believe. Will a third of the world’s population get swine flu? Nobody knows that at the moment. But even if they do, I don’t see, at least at the moment, any difference in principle to a normal wave of influenza. Perhaps swine flu would have gone unnoticed until today if it were not an influenza virus but another, unknown virus.
Jefferson: Wait a minute! These numbers are nothing but estimates. But first and foremost, you have to distinguish between influenza-like infections and true influenza. The symptoms – sudden high fever, aching limbs, respiratory symptoms, possibly bronchitis and pneumonia – are the same for both. But only true influenza is actually caused by influenza viruses. influenza-like infections, on the other hand, are caused by over 200 different pathogens. However, the figures for so-called influenza deaths always include deaths caused by all these other pathogens. If an old person dies of pneumonia, no one takes a throat swab to find out whether it was actually a real influenza virus that killed him. On average, only seven percent of influenza-like infections are actually caused by influenza viruses. The importance of these viruses is systematically overestimated.
Jefferson: Limiting it to influenza is not only wrong, it’s actually very dangerous. Do you remember SARS? That was a really dangerous epidemic. It came fast like a meteor and many people died. SARS took us by surprise because it was caused by a completely unknown coronavirus. Where did this virus come from? Where did it disappear to? Or is it still there? We still don’t know all that. And every year new, strange pathogens are discovered. For example, the bocavirus, which can cause bronchitis and pneumonia in small children. Or the so-called metapneumovirus, which in studies was responsible for more than five percent of influenza-like illnesses. We should remain vigilant in all directions!
SPIEGEL: But in the great pandemic of 1918/19, it was real influenza viruses that went around the world and killed up to 50 million people – or do you deny that too?
Jefferson: Unfortunately, all we can say is: we don’t know. I suspect that the whole thing is much more complex than we can imagine today. Perhaps Robert Koch’s postulate that a pathogen causes a disease falls short with all these viruses that produce influenza-like symptoms. Why, for example, don’t we get influenza in the summer? After all, the pathogens are there all year round! The German physician and hygienist Max von Pettenkofer developed a theory on this back in the 19th century, according to which the environment can change the disease through contact with the pathogen. I think it would be worthwhile to continue research in this direction. Then we could perhaps also better understand the pandemic of 1918/19 or assess the dangers of swine flu.
SPIEGEL: For years you have been systematically evaluating all studies on seasonal influenza vaccines for the Cochrane Collaboration. How well do they protect?
Jefferson: Not very well. An influenza vaccination can do nothing against the large number of influenza-like infections anyway, because it is only directed against influenza viruses. Therefore, the vaccination does not change anything about the increased overall mortality during the winter months. But even against influenza viruses, vaccination provides only moderate protection at best. Among other things, there is always the danger that the circulating influenza viruses change after the vaccine has been produced, so that in the worst case the vaccination becomes ineffective. At least the few good studies that exist show that vaccination works best in young, healthy adults. Children and the elderly, on the other hand, receive little or no benefit.
SPIEGEL: Is there any good reason at all to have a influenza vaccination?