A lot of the talk of new strains of "Covid-19" tend to be quite overblown. I'm not saying that its impossible or that there isn't a new strain, but the likelihood of a TRUE NEW STRAIN (Strain meaning changes to the viruses pathophysiology that confer change to mechanics) is rare.

Yes SARS-CoV-2 is an RNA virus which means it will mutate at a faster rate than other non-RNA viruses, it still is fairly slow, with mutations occurring once every 30,000 pairings.

The coding aberration of the single stranded RNA into double stranded DNA has to occur PEFECTLY.

What this in essence means is that out of those 30,000 pairs that it takes to get a single mutation from the original RNA, the mutation would need to be at a position that affects the spike or other integral point of the virus' pathophysiology that affects binding & infection.

Then you would need that one variant to become dominant, in essence, that mutated strain of RNA would need to go on and infect more cells than any other type and avoid destruction either by immunological means or another mutation which nullifies its properties to produce another.

Assuming the "strain" makes it that far, it would then STILL need to be among the viral particles that shed and manage to infect another individual, of which the process would need to repeat AGAIN and AGAIN and AGAIN, overcoming steep odds mathematically each time.

While changes that make the virus possibly more resilient, lysogenic, & milder (to ward off immune detection) make this a lot more likely to occur, it doesn't mean the virus gains any KNOWN benefits in regards to transmission or added virulence which would not be a new "Strain".

While this is an overly simplified explanation/bastardization of the process, there are people much more qualified and able to go FAR MORE GRANULAR on the topic than I am which can help those who can understand the explanation feel a bit more secure.

Basically, don't worry TOO much about a "Deadly mutation."

In the off chance we get a mutation in transmissibility (Assuming it hasn't already occurred) our vaccine assortment in distribution and others in production would likely still be effective.