Question

What type of genome alterations result in pandemic strains?

4. When was influenza virus discovered and what was known about it in 1918?

5. From where do most experts think that the influenza virus of 1918-1919 originated, and how was it passed to humans?

Answer 1

3. The outer coat protein like hemagglutinin (HA), neuraminidase (NA), variations are the one which result in pandemic stains/

4. H1N1 presently classified under type A influenza virus was the first one to be discovered in 1918. This virus was responsable for spanish flu. It infected 500 million people and is responsable for death of 50 million.

5. Despite its name, historical and epidemiological data cannot identify the geographic origin of the Spanish flu. However, several theories have been proposed.

A 2018 study of tissue slides and medical reports led by evolutionary biology professor Michael Worobey found evidence through phylogenetic analyses that the virus likely had a North American origin, though it was not conclusive. In addition, the haemagglutinin glycoproteins of the virus suggest that it originated long before 1918, and other studies suggest that the reassortment of the H1N1 virus likely occurred in or around 1915

Oxford and his team postulated that a precursor virus, harbored in birds, mutated and then migrated to pigs kept near the front

A report published in 2016 in the Journal of the Chinese Medical Association found evidence that the 1918 virus had been circulating in the European armies for months and possibly years before the 1918 pandemic. Political scientist Andrew Price-Smith published data from the Austrian archives suggesting the influenza began in Austria in early 1917

A report published in 2016 in the Journal of the Chinese Medical Association found no evidence that the 1918 virus was imported to Europe via Chinese and Southeast Asian soldiers and workers and instead found evidence of its circulation in Europe before the pandemic. The 2016 study suggested that the low flu mortality rate (an estimated one in a thousand) found among the Chinese and Southeast Asian workers in Europe meant that the deadly 1918 influenza pandemic could not have originated from those workers. Further evidence against the disease being spread by Chinese workers was that workers entered Europe through other routes that did not result in a detectable spread, making them unlikely to have been the original hosts.