A new investigation from the University of Arizona revealed that the year people were born could play a significant role in their chance of surviving a pandemic of animal-origin influenza.

Published in the journal Science, the study showed that the first time children are exposed to the flu, they create “imprinting” antibodies that will protect them against infections in the future. Until this paper, researchers believed that previous exposure to a flu virus only provided little immunological protection against animal-origin influenza. The team of scientists from the University of Arizona in Tucson and the University of California, Los Angeles, claim that they can now explain why younger people are more affected by some flu outbreaks.

Man with a flu
The team estimated that patients who had been exposed to a virus with the same protein motif in their childhood had a 75 percent protection rate against severe disease and 80 percent protection rate against death. Image credit: iStock.

Orange lollipops vs. blue lollipops

The researchers compared their findings with a sweet-based analogy, explaining that people who were given an orange lollipop in their childhood are less likely to be affected by a similar orange flavor later in their lives. In contrast, they would certainly be severely affected if they are exposed to a blue lollipop in the future.

“In the lollipop analogy, people born before the late 1960s were exposed to ‘blue lollipop’ influenza as children (H1 or H2),” as explained by researcher Michael Worobey, according to the Huffington Post.

These older groups are less likely to suffer from serious illnesses or die from that strain, compared to young adults who were first exposed to H3 as children and were killed by an H1 virus because they were not protected against it.

The researchers found that these older groups rarely succumb to avian H5N1 —which shares a ‘blue’ hemagglutinin— but often die from ‘orange’ H7N9,” as explained by researcher Michael Worobey, according to the Huffington Post.

He added that the same process could explain the rare mortality patterns that resulted from the 1918 “Spanish flu” outbreak. More adults died from it compared to mortality rates among young people. The first infection can determine either success or failure against flu strains, Worobey said. He noted that the same imprinting that can provide protection could be hard to alter with vaccines, as the Huffington Post reported.

Jonathan Ball, who teaches molecular virology at University of Nottingham, said the research provides an understanding of why people have been vulnerable to different strains of bird influenza over the past century, as reported by the BBC. Still, the results came from analysis of patient records and Ball noted they needed to be validated in a laboratory.

Source: The Huffington Post