In 1918, as one global devastation in the shape of World War I came to an end, people around the world found themselves facing another deadly enemy, pandemic flu. The virus killed more than 50 million people, three times the number that fell in the Great War, and did this so much faster than any other illness in recorded history.
But why was that particular pandemic so deadly? Where did the virus come from and why was it so severe? These questions have dogged scientists ever since. Now, a new study led by the University of Arizona (UA) may have solved the mystery…
They hope the study not only offers some new clues about the deadliness of the 1918 pandemic, but will also help improve strategies for vaccination and pandemic prevention, as Prof. Worobey explains:
“If our model is correct, then current medical interventions, especially antibiotics and vaccines, against several pneumonia-causing bacteria, could be expected to dramatically reduce mortality, if we were faced today with a similar set of pandemic ingredients…”
Researchers reconstructed the origins of the 1918 pandemic virus, the classic swine flu and the postpandemic seasonal H1N1 flu virus lineage that circulated between 1918 and 1957, to find out why the 1918 pandemic was so deadly…
For their investigation, the researchers developed an unprecedentedly accurate “molecular clock,” a technique that looks at the rate at which mutations build up in given stretches of DNA over time…
Prof. Worobey and his team used their molecular clock to reconstruct the origins of the 1918 pandemic virus, the classic swine flu and the postpandemic seasonal H1N1 flu virus lineage that circulated between 1918 and 1957…
They found that a human H1 virus that had been circulating among humans since around 1900 picked up genetic material from a bird flu virus just before 1918 and this became the deadly pandemic strain.
Exposure to previous strains of flu virus does offer some protection to new strains. This is because the immune system reacts to proteins on the surface of the virus and makes antibodies that are summoned the next time a similar virus tries to infect the body.
But the further away the new strain is genetically from the ones the body has previously been exposed to, the more different the surface proteins, the less effective the antibodies and the more likely that infection will take hold.
Prof. Worobey notes…”We believe that the mismatch between antibodies trained to H3 virus protein and the H1 protein of the 1918 virus may have resulted in the heightened mortality in the age group that happened to be in their late 20s during the pandemic.”
He says their finding may also help explain differences in patterns of mortality between seasonal flu and the deadly H5N1 and H7N9 bird flu viruses.
The authors suggest perhaps immunization strategies that mimic the often impressive protection that early childhood exposure provides could dramatically reduce deaths from seasonal and new flu strains.
Biologists of this calibre are walking encyclopedias of science, history, chemistry and the knowledge to assemble it all within the guidance of evolution into a unique illuminating dialectic.
It is a delight to stand inside the cone of enlightenment made possible by dedication to science, the addition of something of value to human understanding.
OTOH, you may spend your spare time watching reality TV. 🙂