Has the virus really mutated?! Does this make it even MORE infectious or deadly?

Biology/Immunity Vaccines


There is evidence of a genetic change in the virus’ spike protein, with the new variant (G614) becoming dominant in Europe and the U.S.

These types of small genetic changes are not unusual, and there are a couple of main reasons why a new variant could become dominant:

1) Natural Selection: the new variant is better at surviving and reproducing (more transmissible).

2) Epidemiology of Transmission: the new variant may have initially gotten “lucky” in escaping China to Europe, but then became the dominant strain because cases from Europe were the ones that seeded initial transmission chains in the U.S., which then spread widely.

Q: Can we tell which one of these scenarios is true?

A: Not for sure.

The authors of the new study (linked below), show that clinical samples from G614 have higher levels of viral DNA, and the variant produced higher titers in lab experiments to infect cells in culture (not in people).

This is suggestive, but far from solid evidence that this variant makes the virus more transmissible. Viral RNA may not reflect transmission potential, and the in vitro experiments don’t take into account real world host-pathogen interactions that may increase or decrease transmissibility.

So this new variant MIGHT be more transmissible, but we can’t say that for sure yet.

The GOOD news is there is no evidence that infections due to the G614 variant lead to more severe disease. Studies in the UK, Seattle, and Chicago found no differences in hospitalization outcomes by G614 variant.

Q: What does this mean for a vaccine? Won’t this mess it up if the virus has mutated?

A: So far so good on that front.

While it’s true the vaccine labs have been working with the original D614 variant of the virus, the new variant does not affect the receptor-binding domain of the spike protein, making it less likely to alter the processes necessary for vaccine induced antibodies. What’s more, there is evidence that antibodies produced from natural infection from both genetic variants can cross-neutralize, meaning one would still protect you from the other.

Thus, this new mutation is *unlikely* to have a major impact on the efficacy of the vaccines currently in the pipeline.


Small genetic changes in viruses will naturally happen, and scientists are closely tracking these changes and trying to understand the implications.

These changes are most often neutral, but sometimes good and sometimes bad. This one seems to fall somewhere between neutral to slightly bad, but not terrible. “Mutation” doesn’t have to be as scary as it sounds!

Stay safe and stay sane!

Excellent short commentary on the new mutation study outlining the points above.

The original study

Link to original FB post