Researchers First flu in life influences the later Gripperisiko

First influenza illness in childhood has consequences for the whole life
The likelihood of developing a new form of influenza depends in part on childhood. Researchers now found that the first flu in life affects the risk of various types of flu later.

Researchers at the University of Arizona at Tucson and the University of California, Los Angeles found in a study that the first life-threatening flu has an impact on the likelihood of new forms of flu later in life. The physicians published the results of their study in the journal "Science".

A flu disease is usually very unpleasant and can put those affected out of action for a few days. Physicians now found out that the first flu in life affects which forms of the flu we are most vulnerable to later in life. (Image: Viacheslav Iakobchuk / fotolia.com)

Physicians examine 18 strains of influenza A
The researchers studied 18 different strains of influenza A and the hemagglutinin protein on their surface for their study. They found that the likelihood of developing a new form of influenza depends in part on the type of flu we first encountered in our lives. There are only two types of hemagglutinin protein, explain the experts. The body is protected from the first protein that enters our body through a flu. However, with the considerable disadvantage that we are particularly at risk from the second protein.

Immune system produces antibodies by flu
The current discovery may explain why some influenza outbreaks cause more deaths and serious illness in younger people, say the authors. When a human's immune system first encounters an influenza virus, it produces antibodies, the researchers explain. These so-called receptor proteins are known as hemagglutinin and adhere to the surface of the virus.

There are only blue or orange lollipops
If you compare the proteins with lollipops, there are only two different varieties. For example, there would only be blue and orange lollipops, explains Professor Michael Worobey of the University of Arizona. People born before the late sixties were exposed to influenza viruses H1 or H2 as children. In our example, we consider these flu viruses as blue lollipops, the expert adds.

People born before the late sixties are more susceptible to H7N9
In later life, such people rarely suffer from other flu, which build on the virus H1 or H2, explain the doctors. But, for example, they contracted H7N9 faster and even died of it. In other words, one could say that we tolerate the blue lollipops but are sensitive to orange lollipops, the researchers explain.

Protein provides protection against certain diseases
The research team considered several cases of H5N1 and H7N1 (two forms of so-called bird flu). These forms of the disease have affected hundreds of people but luckily they have not developed into a pandemic. The physicians found that people have about 75 percent protection against serious illnesses and about 80 percent protection against the fatal consequences of the disease when the patients were exposed to a virus with the same protein during childhood.

Reasons for the "Spanish flu" noted?
The current discovery may explain the unusual impact of the so-called "Spanish flu" in 1918. This was especially deadly in young adults, explains Professor Worobey. These young adults died of H1 virus. The analyzed blood cells from many decades showed that the affected persons were exposed to incongruent H3 viruses during childhood. As a result, they were not protected against the H1 virus.

Explanation why the population is susceptible to bird flu
The same pattern can be observed today with 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 bird flu. Unfortunately, there is currently a recurrence of bird flu in Germany. (As)