The first flu illness in childhood has consequences for life
The likelihood of developing a new form of flu depends in part on childhood. Researchers have now found that the first flu in life affects the risk of various types of later flu diseases.
Scientists from the University of Arizona at Tucson and the University of California, Los Angeles, found in a study that the first flu you suffer in life affects your likelihood of developing new forms of flu later in life. The doctors published the results of their study in the scientific journal "Science".
Doctors examine 18 strains of influenza A
For their study, the researchers examined 18 different strains of influenza A and the hemagglutinin protein on its surface. They found that the likelihood of developing a new form of flu depends in part on the type of flu we were the first to suffer from in our lives. There are only two types of hemagglutinin protein, the experts explain. The body is protected from the first protein that gets into our body through flu. However, with the considerable disadvantage that we are particularly at risk from the second protein.
Immune system produces antibodies through flu
The current discovery could explain why some flu outbreaks cause more deaths and serious illnesses among younger people, the authors say. When a human's immune system encounters a flu virus for the first time, it produces antibodies, the scientists explain. These so-called receptor proteins are known under the name hemagglutinin and adhere to the surface of the virus.
There are only blue or orange lollipops
If you compared the proteins to lollipops, there would only be two different types. For example, there would only be blue and orange lollipops, explains Professor Michael Worobey from the University of Arizona. People who were born before the late 1960s were exposed to the H1 or H2 flu viruses as children. In our example, we consider these flu viruses as blue lollipops, adds the expert.
People born before the late 1960s are more prone to H7N9
In later life, such people were less likely to get other flu, which are based on the H1 or H2 virus, the doctors explain. But they fell ill with H7N9 more quickly and even died of it. In other words, you could say that we tolerate the blue lollipops, but are sensitive to orange lollipops, the scientists explain.
Protein offers protection against certain diseases
The research team looked at different cases of H5N1 and H7N1 (two forms of the so-called bird flu). These forms of the disease have affected hundreds of people, but fortunately they have not developed into a pandemic. Doctors found that when patients were exposed to a virus with the same protein in childhood, they had an approximately 75 percent protection rate against serious illnesses and about 80 percent protection against the fatal consequences of the illnesses.
Found reasons for the "Spanish flu"?
The current discovery could explain the unusual impact of the so-called "Spanish flu" in 1918. This was particularly fatal in young adults, explains Professor Worobey. These young adults died of an H1 virus. The analyzed blood cells from many decades showed that those affected were exposed to inconsistent H3 viruses in childhood. However, this did not protect them against the H1 virus.
Explanation why the population is susceptible to bird flu
The same pattern can be seen today in current H5N1 and H7N9 cases. This suggests that the same basic processes that triggered the pandemic in 1918 could also create the next major flu pandemic, the authors explain. The new study now provides reasons why the human population is susceptible to different strains of avian flu. Unfortunately, bird flu is currently re-emerging in Germany. (as)