Nearly a year has passed since the COVID-19 outbreak began, and more than 100 million confirmed cases have been recorded worldwide.
Mutated variants of the virus have recently garnered attention and concern. Public health officials are worried these new viral strains are a new and relatively unknown complication in the fight against the pandemic.
But where do these variants come from? How do the mutations develop? And why are they potentially more dangerous?
Viruses evolve quickly, and Xue said this is mainly because of two factors — generation time and mutation rate.
The life cycle of a virus is short and they reproduce quickly. Xue said if humans have new generations every 20 or 30 years, then viruses have new generations in a matter of hours.
A virus’s life cycle begins when it makes contact with a host cell. Xue said viruses depend on host cells to survive and they reproduce by “hijacking” a cell’s “machinery” to replicate the virus’s genetic code and proteins.
Xue said it depends on the type of virus, but they can reproduce themselves 100 times per host cell. So their reproduction rate grows exponentially both inside a host and in the amount of hosts they infect over time.
When viruses use cells to replicate themselves, Xue said, they are