In the latest episode of This Week in Virology[1] five virologists discuss this issue.
Some points they made:
"It's a variant. It's not a strain. A strain is a virus with a new biological property. There have been no new properties ascribed to this isolate other than sequence differences, which is not enough to make a strain.. nor have we seen any other new strains of SARS-CoV-2 that anybody's demonstrated to be biologically different. None. It hasn't happened yet. I'm not saying it couldn't but it hasn't."
"Nobody's done any experiments to determine the effects of these changes on any property of the virus. Yet when a journalist calls up a scientist and say "What do you think?" and the scientist says "These could have an effect on virulence or transmission or antibody neutralization," somehow that gets translated in to "It's making the virus more virulent" and that's what's circulated and a dozen people this week said to me "What do you think about these mutations in the UK that make the virus more virulent, more transmissible, more resistant to neutralization by antibodies?" None of that has been shown, folks! It's speculation. There's no paper on any of this."
Some points they made:
"It's a variant. It's not a strain. A strain is a virus with a new biological property. There have been no new properties ascribed to this isolate other than sequence differences, which is not enough to make a strain.. nor have we seen any other new strains of SARS-CoV-2 that anybody's demonstrated to be biologically different. None. It hasn't happened yet. I'm not saying it couldn't but it hasn't."
"Nobody's done any experiments to determine the effects of these changes on any property of the virus. Yet when a journalist calls up a scientist and say "What do you think?" and the scientist says "These could have an effect on virulence or transmission or antibody neutralization," somehow that gets translated in to "It's making the virus more virulent" and that's what's circulated and a dozen people this week said to me "What do you think about these mutations in the UK that make the virus more virulent, more transmissible, more resistant to neutralization by antibodies?" None of that has been shown, folks! It's speculation. There's no paper on any of this."
[1] - Starting at about 54 minutes in to episode 696: https://www.microbe.tv/twiv/twiv-696/