Severity Of Flu Linked To Year Of Birth, Research Says
The lollipop analogy suggests that your year of birth year predicts, how you will be affected by the animal-origin-influenza A virus. Though the prediction can be extended to a complete diagnosis the association proved shows that there are connections between the first time a person gets infected by a flu and his possibility to be severely attacked by influenza A in the later stage.
Combined University Research on Flu viruses
According to the researchers from University of Arizona in Tucson and the University of California, Los Angeles, the research results answer the important question of why certain people are severely affected by Influenza A viruses that it even causes death at times.
Till today it was perceived that exposure to influenza virus in the early stages of life leads to little or no immunity against similar attacks in the future especially with regard to animal-origin-influenza virus. The study result shows major breakthrough finding that helps in handling patients at times of flu outbreaks by relating them to their early childhood flu complaints.
Pandemics can cause serious damage
Michael Worobey , one of the senior author of the study and the head of Department of Ecology and Evolutionary Biology at University of Arizona, explained that "Even a comparatively weak, mild pandemic flu event like the 2009 H1N1 (swine flu) outbreak is a trillion-dollar affair." He also quoted the major pandemic of 1918 that killed large numbers of people and shut down the entire world economy.
The research on bird-origin flu viruses
The two bird-origin influenza A viruses, H5N1 and H7N9, that cause "bird flu" were studied in this research. Each of these viruses have caused severe damage to life of humans and are a major global concern. If the virus jumps from birds to humans at some point and gain mutations they could spread rapidly and lead to a pandemic.
What is "immunological imprinting"?
By analyzing the data from every case of severe illness and death caused by influenza A virus under the study, the researchers found that whichever strain an individual had been exposed to during his or her childhood at the very first infection with flu virus, they will gain immunity against that strain of avian-origin flu strains and can be free of getting infected in a future infection. Researchers call this "immunological imprinting" and say that it appears to be completely dependent on the very first flu exposure in a person's life and it is difficult to reverse.
Flavors of influenza A virus hemagglutinin
When a person for the first time in his life gets exposed to flu virus his immune system generates antibodies to hit the hemagglutinin, a lollipop-shaped, receptor protein that will stick out from surface of the virus. Like our usual lollipops that are of different colors and flavors, influenza viruses also have distinguishing flavors that make up their hemagglutinins. However, all the 18 known subtypes of influenza A virus hemagglutinin can be categorized under two main "flavor" groups.
The lollipop analogy
The lollipop analogy says that a human affected by 'orange lollipop' flu as a kid shall gain immunity against all the avian-based-influenza viruses falling under that flavor group. However if a person was affected by 'orange lollipop' flu as a kid and is infected by a 'blue lollipop' group virus in the future the antibodies "won't protect you against this novel, 'orange' strain." Says Worobey.
Thus, the severity of your flu and how bad you can be affected by influenza A virus depends on your year of birth in which you will have your first exposure to flu. The good news in the bad news is that you are safe from one group of the two groups of flu viruses!