It is a given that there will be a bird flu pandemic, the question is when and how we are prepared for it, points out the pathologist, with a large research project on infections, doctor at the University of Ioannina Giorgos Pappas.
In an interview with Agência FM, Mr. Pappas emphasizes that the enormous evolutionary steps of the virus are unexpected and cause concern among experts, that the next evolutionary step and the virus learning to overcome defenses may be waiting for us around the corner tomorrow or the day after tomorrow for man, when it starts to stick to him. As he reports, bird flu remained for years as the main candidate as a potential cause of some subsequent pandemic. “For at least twenty years, there have been scenarios of preparation in the United States for such an eventuality. The problem, however, was that this eventuality required several evolutionary stages on the part of the virus. The bird flu virus does not easily infect humans. It cannot be easily transmitted from person to person. Therefore, it lacks two basic elements to create and start a pandemic. However, it does have some other characteristics. Which very few people are immune to this flu, because it is caused by executives we have not met before.”
The evolutionary stages of the virus over the last two years
According to Mr. Pappas, what has happened in the last two years is that bird flu in the form of H5N1 has started to make great evolutionary advances. “It first started from Europe to show an extension of its seasonality. It didn’t just affect birds and didn’t cause problems only in the winter months, but it started to spread throughout the year. Then it started to affect some wild waterfowl much more strongly and cause mass deaths,” he says, explaining: “The example we had in Prespes in 2022 was very typical, where at least 10% of the total population of silver pelicans died. And although it is described as the biggest ecological disaster that has occurred in Greece, it has not received the attention it deserves. The virus continued to evolve and first passed through waterfowl in the American continent, not only in the USA, but slowly started to descend and reach South America, making some recombination locally with other low pathogenic bird flu strains, which may have circulated there.”
The problem, as the pathologist notes, “is that it started affecting mammals, not just in Europe, where we had influxes on mink farms in Spain and Finland, not just foxes, bears and animals that happened to eat a dead bird and became infected, not just cats in Poland, where last summer we had a lot of outbreaks because they were fed infected chickens. It started killing off populations like seals and sea lions en masse, from Latin America to Antarctica. Fortunately, penguins seemed to be somewhat resilient.”
Why detection in cattle worries scientists
But the worst thing, as Pappas points out, is that since March of this year cases have started to appear in cattle herds in the US and at the moment there are officially 140 detections of clusters of cases in herds in 12 US states. However, he says, this number is expected to increase.
But why are scientists so concerned about detection in cattle? “First of all, cows are an animal that we did not expect to be infected by bird flu. So the virus has made another major evolutionary leap. Secondly and worse, the bird flu virus in cows mainly infects the udders. Scientists have discovered, and there are a number of recent publications, that the udders of cows are a very bad place for the flu virus to take hold. It is a mixing and recombination vessel and normally, such a mixing vessel in an animal or animal organ is “necessary” to start a pandemic. That is, humans do not easily contract bird flu, because the receptors they have in the respiratory tract are different from those of birds. In the udders of cows, however, there are both receptors, both human and bird. And this means that the virus has already started to train, love and attach itself to both receptors. So the virus has taken the first step of many that are still necessary to start systematically attacking humans.” It also infects milk and the virus can be detected in large quantities, Pappas points out, explaining that if the milk is pasteurized there is no risk.
Greece participates in EU pre-order for vaccine
Regarding the vaccination that is only starting in Finland for professionals in contact with fur-bearing animals, poultry farmers, breeders, veterinarians and close contacts, due to multiple outbreaks on fur-bearing farms (mink, fox and raccoon dog), Mr Pappas is asked why something similar is not happening in Greece, which is the second European country in terms of mink production volume. “As far as we know, we do not have any outlets on our own mink farms. Greece has not yet made any decisions on vaccination, but it is participating in the pre-order made by the EU to the company that produces the vaccine, so that some quantities are reserved for our country. Fifteen countries of the European Economic Area participate in the order.”
But how dangerous could this flu be for humans? “If the virus evolves to attack the human respiratory system sufficiently and adapt to our immune defenses, then it has the potential to cause a pandemic wave, without us knowing the severity of the symptoms. This will depend on how well the virus adapts to humans, as well as the fact that no one is immune to this strain.”
Source: RES-MPE