Attack of the Mutants
Current thinking is that these versions are more contagious. I've heard two theories for why this may be true. One is that the virus might be better at reproducing inside the body, creating a higher viral load, meaning the victim would shed more viral particles when contagious. This makes it more efficient at getting from victim to victim.
A second is that mutations improve the "spike protein" the virus uses to bind to a cell, allowing it to inject its payload and hijack the cell's machinery. This makes the virus more efficient at invading cells once it has entered your airway.
One study summary I read says that there are not only spike protein changes but other changes too, which taken together make the virus a more efficient invader. This includes possible changes that may help the virus evade antibodies from previous infections. Awesome!
So far experts seem confident that existing vaccines will continue to work, and there is even some research to support this. But the situation is worrisome because the UK strain is becoming widespread in Europe and is expected to be the dominant strain in the US by March. If it acquires some additional mutations that make it resist vaccine-produced antibodies and t-cells, we could be back to square one.
An interesting article in The Atlantic quotes experts as saying all the mutations are similar but have arisen independently, a sign that the changes confer some important evolutionary advantage. We are seeing this high rate of mutation because the virus is running rampant, creating lots of opportunities for it to develop multiple adaptive changes.
And here's another thing for us to be proud of! The greatest country with the best health care system in the world is not doing enough genetic sequencing to properly monitor for mutations that might be occurring here. One report says that the UK has uploaded 151,859 sequences to GISAID (a database). But "despite having a larger population than the UK, a sophisticated biomedical research industry, and tens of millions more cases of Covid-19, to date US labs have only uploaded 69,111 sequences, according to GISAID." That's less than half of the UK's total. One researcher quoted in the article felt this way: "It’s embarrassing, is all I can say."
