Circulating in China new strain of H7N9 bird flu virus has a pandemic potential

Almaty. October 20. Silkroadnews - A new strain of the H7N9 bird flu circulating in China has a pandemic potential, Singapore’s The Straits Times reported.
“Lab experiments on a new strain of the H7N9 bird flu circulating in China suggest the virus can transmit easily among animals and can cause lethal disease, raising alarm that the virus has the potential to trigger a global human pandemic,” the researchers said.
It is noted that the H7N9 virus has been circulating in China since 2013, causing serious disease in people exposed to infected poultry. Last year there was a big surge in disease incidence, and the virus was split into two distinct strains, which are so different from each other that the H7N9 vaccine has become useless.
It is reported that one of the strains also became very pathogenic, that is, it can kill infected birds, posing a threat to the poultry farming.
“US and Japanese researchers studied a sample of this new highly pathogenic strain to see how effectively it spread among mammals, including ferrets, which are considered the best animal model for testing the transmissibility of influenza in humans. In the study published in Cell Host & Microbe, flu expert Yoshihiro Kawaoka of the University of Wisconsin and colleagues tested a version of the new H7N9 strain taken from a person who died from the infection last spring,” the publication said.
To test transmissibility, the team placed healthy ferrets next to infected animals and found that the virus easily spreads from cage to cage, suggesting that the virus can be transmitted by respiratory droplets.
Two of the three healthy ferrets infected in this way died, which, according to Kawaoka, is “extremely unusual” and suggests that even a small amount of the virus can cause a severe disease.
As the publication reminds, since 2013 the H7N9 bird flu virus has struck at least 1562 people in China and killed at least 612 people. About 40% of people hospitalized with the virus died. In the first four epidemics, the virus did not show significant changes. But in the last flu season there were about 764 cases - almost a half of all cases since 2013.
It is reported that the most recent global pandemic was caused by the H1N1 swine flu in 2009 that infected millions and killed more than 200,000 people in the world.
Some researchers are concerned that a highly pathogenic strain can cause even heavier disease and higher death rates, but the mortality from a low pathogenic strain is already “alarmingly high”.
Existing H7N9 vaccines are based on the 2013 strain. It is reported that a new vaccine based on a low pathogenic strain of the mutated virus has already been developed, though it has yet to be tested in people.
In February, China continued clinical trials of vaccines against H7N9, developed by the state-owned Beijing Tiantan Biological. The company said it was developing four more vaccines against the H7N9 virus.