In the past two decades, coronaviruses have produced three deadly global epidemics: SARS, MERS and now Covid-19, all these are deadly diseases. And they all belong to coronaviruses family. You must be wondering what it is about this family of viruses that makes it produce such deadly pathogens. Here are a few things you should know.
They have a high substitution rate
Although the rate is lower than the other pandemics like HIV or hepatitis C, but like many RNA viruses, coronaviruses too have a high substitution rate. This higher substitution rate means that coronaviruses can rapidly exploit situations in which they come into contact with new hosts (i.e., humans).
They possess the longest genomes of all known RNA viruses
Do you know why coronaviruses mutate so rapidly? It is because they have the longest genomes of all known RNA viruses. With more sections in their genome, there are more potential errors when the virus copies itself, which increases the production of new strains.
They are highly susceptible to recombination
Through recombination, multiple viruses interact in the same organism (e.g., humans). It is one of the ways viral strains emerge. Research predating the emergence of Covid-19 has shown that, of all the many coronavirus strains that are out there, a human coronavirus known as HCoV-HKU1 is among those most highly susceptible to recombination. It is also one of the coronaviruses most closely related to Covid-19, along with SARS and MERS: all are members of the subset of betacoronaviruses.
They are exceptionally adaptive
Coronaviruses can replicate in different species. Unlike smallpox, they can infect many species at the same time. Humans, bats, pigs, cattle, mice, chickens, civet cats, raccoon dogs, ferret badgers and camels, they can all be infected by coronavirus.
bats harbor many viruses
It is believed that Covid-19 may have initially jumped from bats to humans. Ebola, Marburg, Rabies, Hendra and Nipah all came from bats. We can now add Covid-19 to that list. A research conducted in 2017 in Kenya identified several novel coronaviruses that had genomic sequences closely related to human coronaviruses.
They’re heavier than other viruses
Coronaviruses are physically larger and heavier than other known respiratory viruses. So while Covid-19 infects hosts via mucus droplets, its infectious range is lower relative to other viruses because its mass limits how far it can travel before succumbing to gravity. Case in point, coronaviruses can only travel about one to two meters, less than seven feet, before they start falling to the ground. Compare that to much more infectious viruses like measles or chickenpox, both of which are much lighter and able to remain airborne on tiny dust particles.