17 January 2024

Four cold-causing coronaviruses may provide clues to COVID's future

the origin of 4 mild human corona viruses [5] (©Science)

Jon Cohen discusses 4 lesser known corona viruses in his Science article Four cold-causing coronaviruses may provide clues to COVID's future. They are not well known because they did not cause a deadly pandemic. But they are coronaviruses. He interviews the discoverers, and tries to answer the question whether those four coronaviruses show how SARS-CoV-2 will evolve in the future. 

I made an overview of the 4 corona virus species Jon Cohen discusses in his Science article (with links to the Wikipedia articles). Each virus has its own Wiki page:

229E    1966    USA
Alphacoronavirus genus.  APN 27.395 b
OC43   1967    USA
Betacoronavirus 1.  Neu5Ac30.741 b
NL63   2003   Netherlands  Alphacoronavirus genus. 
 ACE2
27.553 b
HKU1  2004   Hong Kong Betacoronavirus.  Neu5Ac29.926 b

3 killer Corona viruses in humans [5] (©Science)

I didn't know that HCoV-NL63 was discovered simultaneously by Dutch virologists Lia van der Hoek [2] (Amsterdam University Medical Center) and Ron Fouchier, Ab Osterhaus et al [3] (Erasmus Medical Center, Rotterdam) back in 2003. Ron Fouchier and Ab Osterhaus are well-known virologists in the Netherlands, but I didn't know Lia van der Hoek. 

The evolutionary relationships between the four coronavirussen and SARS-CoV-1 are murky. It is also frustrating that the origins of the viruses are unclear. Unfortunately, Cohen doesn't make a detailed comparison of the genomes. All human coronaviruses have animal origins: SARS-CoV, SARS-CoV-2, MERS-CoV, HCoV-NL63 and HCoV-229E are considered to have originated in bats; HCoV-OC43 and HKU1 likely originated from rodents [4]. NL63 seems to have originated from recombination of two different viruses.  

Are those 4 mild viruses the ancestors of SARS-CoV-2? According to Cohen "the surface protein of SARS-CoV-2, called spike, differs markedly from the ones that stud its cold-causing cousins." 

Did the common cold coronaviruses prepare our immune system? “It has been well established that pre-pandemic, some people had pre-existing immune reactivity to SARS-CoV-2. Obviously that did not prevent a pandemic. On the other hand, "People who had prior SARS-CoV-2 infections were 50% less likely to have symptomatic disease from one of the four."
Does SARS-CoV-2 become less deadly? Scientists disagree. According to Lia van der Hoek SARS-CoV-2 has become milder. Others say that Omicron is still deadly.

Conclusion

To me it is clear that the behaviour of viruses and their interactions with humans and other animals don't allow for quick conclusions, let alone strong opinions from non-virologists. Viruses are tiny 'creatures', they occur in unimaginably huge numbers, are everywhere, are very diverse, they remain out of our view, are only inferred when we get sick, can be identified and analyzed only by scientists with sophisticated lab techniques. And importantly: they evolve, they mutate, they recombine, they jump from one animal species to another whenever they see an opportunity. They have evolved over millions of years camouflage and sabotage strategies to escape the attacks of our immune system. All this together makes viruses frighteningly and frustratingly unpredictable and impossible to eradicate.

click on label SARS-CoV-2 for previous posts

 

Postscript 19 jan 2024

A publication of Jesse Bloom about a Chinese submission of the first SARS-CoV-2 sequence on 28 dec 2019. Detail: "and in early 2020 the Chinese government ordered commercial sequencing companies to destroy all samples."


Sources

  1. Jon Cohen (2024) Four cold-causing coronaviruses may provide clues to COVID's future 11 Jan 2024 
  2. Lia van der Hoek et al (2004) Identification of a new human coronavirus, Nature Medicine.
  3. Ron A. M. Fouchier, Albert D. M. E. Osterhaus, et al (2004)  A previously undescribed coronavirus associated with respiratory disease in humans, PNAS.
  4. Jie Cui, Fang Li & Zheng-Li Shi (2019!) Origin and evolution of pathogenic coronaviruses, Nature reviews microbiology. Please note that SARS-CoV-2 is not mentioned! The article was published before the SARS-CoV-2 pandemic started! 
  5. All the illustrations show animal-to-human transmission, however the reverse also happens: from human to chimps!  [18 jan 2024]

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