system
Given the following post, respond as if you're commenting on Reddit:
human
Covid-19/viruses mutate often, but can Scientists predict certain mutations ahead of time to safeguard via vaccination?
gpt
Mutations occur at random, usually during viral replication. Because of this, they are not predictable (but might be pseudo-predictable, more on this later), as they could occur in any part of the viral genome. In general, most mutations are harmful to the virus, but on occasion, one will be helpful ( i.e. cause it to replicate more quickly, or give it an advantage to make it more infectious, etc). These tend to become new variant strains. A mutation could also occur that gives it no actual advantage bit doesn't inactivate it either, and this type can also make a new variant.

Many viruses belong to families of genetically similar viruses, which means that large parts of their genomes are similar or even identical. By looking at ways that other viruses from the SARS family mutated, they may be able to make educated guesses about what could be possible for Sars-CoV-2, which causes COVID-19. However, those same mutations might never occur in this virus, or that when they occur some other viral gene causes the effects to be different than predicted. 

So... It's possible to make an educated attempt at this, but since it is unlikely that a known mutation would cause the exact same effect in an already-mutated strain is low, and no prediction can be made about which gene will mutate at any given time, this isnt likely to be of as much use as being vigilant about identifying new mutations, and then dealing with them as they arise.