Context

Scientists have identified a new ‘re-assorted’ influenza virus from pigs in China that has pandemic potential. The virus has shown ‘increased human infectivity’ in swine industry workers. 

About

Key-highlights of the Study

• The study was based on extensive surveillance done among pig populations in 10 provinces of China from 2011-2018.
• The serological exercise showed that the new gene of the H1N1 virus has efficient infectivity and transmissibility in ferret models. 
• The viruses fell into six different genotypes, with the G4 strain becoming predominant since 2016.
• They found that the G4 strain is a blend of three lineages-
  • one similar to those found in European and Asian birds
  • one linked to the 2009 H1N1 pandemic virus
  • a North American H1N1 triple-reassortant virus that has genes from avian, human, and swine sources
• When they tested the G4 virus in the lab, they found that it had features similar to the 2009 H1N1 virus.

 About the new flu strain

• The virus, which the researchers call G4 EA H1N1, can grow and multiply in the cells that line the human airways.
• Tests also showed that any immunity humans gain from exposure to seasonal flu does not provide protection from G4. 
• It possesses “all the essential hallmarks of being highly adapted to infect humans”.
• Current flu vaccines do not appear to protect against it, although they could be adapted to do so if needed.
• The new flu strain that has been identified in China is similar to 2009 swine flu, but with some new changes.
  

2009 swine flu The last pandemic flu the world encountered - the swine flu outbreak of 2009 - was less deadly than initially feared, largely because many older people had some immunity to it, probably because of its similarity to other flu viruses that had circulated years before. That virus, called A/H1N1pdm09, is now covered by the annual flu vaccine to make sure people are protected.

• The bad new strain of influenza is among the top disease threats that experts are watching for, even as the world attempts to bring to an end the current coronavirus pandemic.
• So far, it hasn’t posed a big threat, but it is one to keep an eye on.