The scientists at Los Alamos (& others) are tracking SARS2 mutations the way astronomers track asteroids, to protect us from “the big one”. In case of SARS2, some mutations are worse than others. What matters to all of us is that the virus must not... biorxiv.org/content/10.110…
...change (mutate) the parts of its outer shell (its Spike protein) that antibodies stick to to protect us from infection. In the case of this paper, which sounds scary, the mutation they talk about (at the 614th amino acid in the Spike protein) won’t interfere with antibodies.
This mutation makes the virus more infectious and it may be that we’ll need to treat people with more of a particular antibody to stop it, but the antibodies will still be able to bind to this strain. And the vaccines we are developing now, while they don’t teach...
...our immune system to recognize this mutatation, do still teach the immune system to recognize the rest of Spike protein, including the most critical part of it that binds like a hand to the ACE2 doorknob on our cells to enter (infect) them.
So think of this mutation as making the virus’s arm stronger and more effective at turning the doorknob to break into houses (cells) where it can replicate itself. But all the antibodies that a vaccine generates as well as the antibodies that are being produced...
...by biotech companies can all still bind to that hand to stop the virus from grabbing the doorknob. What would be a problem is if the virus mutates the hand part of its Spike protein (known as the receptor binding domain- RBD) to such an extent that it became unrecognizable...
...to the antibodies we trained to recognized the hand of the original SARS2 strain (eg if the virus changes the hand to a claw). When that happens, we’ll need to switch up our vaccines, just as we do for flu each season, to reflect what the new changed virus looks like.
We can do that, but we’re nowhere near that point. So, so far, the mutations Los Alamos has seen are not problematic. The vaccines are still relevant and the monoclonal antibodies that some companies are making will still bind to the strains we’ve seen.
As extra precaution, Regeneron is developing an antibody cocktail, ensuring that if a virus changes part of Spike that one antibody binds to, odds are another antibody will still bind to virus & neutralize it. That’s the same idea as HIV drug cocktails (combinations) that...
...anticipate & prevent the emergence of viral resistance mutations. And vaccines & infections train our immune systems to generate a wide range of antibodies against many parts of Spike protein (or even other parts of the virus), a so-called “polyclonal” antibody response.
So it won’t be just one mutation that lets SARS2 escape our counter-measures. It will have to be many together in one virus. Good to have Los Alamos and others monitoring for that risk. As long as they continue to watch and sequence virus from all over the world, they can spot...
...a real problem and guide antibody and vaccine companies to pivot to that strain. In the meantime, we’re also working on drugs that gum up other viral machinery (like remdesivir does). So the odds of this virus escaping all our countermeasures will be very small.
On another note, Los Alamos folks did mention that they detected evidence of viral recombination, in which two viruses swap bits of code, mixing and matching their features like two slight different Mr Potato Heads swapping parts. If I had to guess, as they do, then...
...this could happen if someone comes into the hospital with a SARS2 infection and catches another strain in the hospital. Hospitals are likely to be breading grounds where different strains share their mutations. That’s what happens with bacteria, which often....
...learn new tricks in hospitals. So it’s going to be important that hospitals are equipped with as many treatments and countermeasures as possible to really shut down infections of all strains, stopping them before they learn each other’s tricks.
This recombination trick is not like what flu does. Flu easily swaps pages of its code b/c it has 8 separate pages of code and can re-assort them with other flu strains. Recombination is more like two similar pages of code being torn in half and exchanged. Harder to pull off.
Here’s an article I wrote explaining differences between how flu and coronaviruses mutate and why’s that means for vaccines. I briefly explain recombination. city-journal.org/coronavirus-va…
For more explanations and Q&A, see my pinned tweet. In the meantime, don’t let the Los Alamos paper or media’s interpretation of it scare you.
And yes, really lame of @latimes to put out such sensational, gratuitously scary, sloppy coverage of science. They should know better. A lot of new discoveries are promptly reported w/o peer review - which I think is a net good - but media can still do its job before reporting.
