My thoughts, for whatever they're worth...
First, I generally don't put a lot of faith in media reporting of scientific research. Much of the time they don't interpret studies correctly, usually focusing on some headlining aspect of the paper while disregarding other aspects that may be just as, if not more, important.
Second, this story is about a pre-publication paper which has neither been peer-reviewed nor accepted for publication. In this case, it's done in order to facilitate exchanging information on SARS-CoV-2/COVID-19, but at the same time it needs to be viewed with a critical eye.
So, I decided to skim through the paper (FYI, available here, if anybody wants to read it:
Spike mutation pipeline reveals the emergence of a more transmissible form of SARS-CoV-2 | bioRxiv).
I'm not entirely convinced of their claims regarding this specific mutation. The study is based on a bioinformatics analysis of genetic data from clinical cases of infection. This means it's based on computer models and not lab results, at least not directly (the genetic information came from actual clinical cases).
They're basing the hypothesized increased infectivity of this mutation based on an increasing number of clinical cases involving viruses with the mutation. In other words, as the rate of infections increase, the number of times they see this mutation also increase. While suggestive, it's not conclusive, IMO. For anyone familiar with research, the phrase, "Correlation does not equal causation" comes to mind.
Another problem is that this study, as far as I can gather, was based on an extrapolation from a small sample in Sheffield, England.
The authors also equate increased infectivity with increased virulence (i.e., more dangerous), but that's not always the case. In some instances, increased infectivity is correlated with decreased virulence. It's an evolutionary mechanism. The primary goal of microbes (and all organisms, in general) is reproduction. In order to increase its ability to replicate, microbes can develop an increased ability to infect hosts so as to better spread. They can also benefit from living inside hosts for longer periods of time, so they become less lethal. An example of this is
Mycobacterium tuberculosis, the bacteria that causes tuberculosis, and it's ability to sutain latent infections that can last for several years before any symptoms appear. It's also possible for both infectivity and virulence to increase at the same time, but I'm not convinced the authors have supported their hypothesis with this paper.
So, I'd say the authors' study is worthy of consideration, but I wouldn't rely on it by itself.
Of course, as I said, I've only skimmed the paper so I may have missed something.
Just my thoughts on the matter.
