MERS CoV accessory proteins interfere with interferon…

This concept (see the paper adjacent and others [6,7]) is not news in the world of Middle East respiratory syndrome coronavirus (MERS-CoV), but it’s interesting to remember in light of some comments that came out of the combined World Health Organization (WHO), the Food and Agriculture Organization (FAO), and the World Organisation for Animal Health (OIE) #tackleMERS meeting in Geneva last week.

The comments, in tweets, were about a talk given by Prof. Malik Peiris…


I was left wondering if another of the reasons we may not have seen MERS cases in humans in Africa – where there are known MERS-CoV variants present in camels [3-5] – could be that the virus has less “well developed” abilities (assumptions galore) to interfere with human responses to it. In other words, infections do happen but with viruses that may be more easily defeated by human early immune responses to a foreign viral invader. Humans in Africa may be able to more effectively clear out any spillover infections due to their viral variants than can humans in the Arabian peninsula infected by MERS-CoV variants that are better at evading innate responses and allowing the virus to establish, mostly showing its presence in those with pre-existing disease of the heart, lungs or kidneys.

 

 

Other reasons for few signs of MERS in Africa were nicely summarised here…

People have probably caught MERS in Africa but the absence of outbreaks recorded there may be due to poor disease surveillance, less contact with camels, or lower rates of underlying conditions like obesity and heart problems that make MERS more severe. [2]

Just some thoughts.

 

References…

  1. https://www.ncbi.nlm.nih.gov/pubmed/24443473
  2. Health experts zero in on camels to fight deadly MERS virus
    https://in.reuters.com/article/us-health-mers/health-experts-zero-in-on-camels-to-fight-deadly-mers-virus-idINKCN1C61OC
  3. Kenyan camel coronaviruses..
    https://virologydownunder.blogspot.com.au/2015/10/kenyan-camel-coronaviruses.html
  4. More MERS molecular masterfulness: Egyptian camels contain lots of anti-MERS-CoV antibodies
    https://virologydownunder.blogspot.com.au/2013/09/more-mers-molecular-masterfulness.html
  5. Geographic Distribution of MERS Coronavirus among Dromedary Camels, Africa
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4111168/
  6. Middle East Respiratory Syndrome Coronavirus Accessory Protein 4a Is a Type I Interferon Antagonist
    http://jvi.asm.org/content/87/22/12489.full
  7. The structural and accessory proteins M, ORF 4a, ORF 4b, and ORF 5 of Middle East respiratory syndrome coronavirus (MERS-CoV) are potent interferon antagonists
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4875403/

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