Delta is a winner. In the viral race to reproduce, it’s outpacing all comers. But virologists have dissected its attributes. And they’ve found it can get much more powerful yet.
At the moment, it’s just a simulation. It takes everything we know about Covid-19’s ability to invade human cells. It breaks this down into its building blocks. It then tests every possible recombination to see what they can do.
The outcome is a ‘Covid Ultimate’. …
This isn’t a prophecy. It’s a possibility. …
[Delta is] certainly a more efficient virus. And that efficiency means viral loads in patients grow quicker.
What is certain is that Covid-19 is the most intensely studied virus in history. HIV may be better understood. But it hasn’t had as much attention at any one time. …
The outside of a virus is covered in spike proteins. These are like grappling arms with different shaped hooks attached. Delta’s hooks are proving sharper than before. And once a cell is snared, the spike protein’ arm’ fuses the virus with the cell. In the case of Delta, this ‘arm’ is also faster and stronger.
“What we’re understanding is that there is a new spike that makes it ‘sticker’ to host cells,” he says. “This then ‘melts’ into the outside of that cell far more efficiently.”
At the moment, Delta is by far the most potent Covid-19 mutation.
“The question is still out there whether or not the virus can evolve to a point where it remains as fit as Delta — producing severe disease and death — in a vaccinated population,” he says. “It’s still early days.”
An ugly possibility:
One potential ‘hook’ mutation stands out from the rest. It makes Covid-19 some 600 times more capable of snaring a victim cell than the original strain.
“We’ve done an experiment where we’ve looked at the full virus spike protein with that particular receptor binding,” says Dr Turville. “To cut a long story short, yes, it transmits much better than Delta.”
But such an ‘ultimate’ mutation isn’t here. It isn’t even close. Yet.
“That receptive binding domain has seven changes over the original virus we saw in early 2020,” he says. “Some variants of concern have some of these changes. But we’ve yet to see all seven locked in”. …
A new study published by Scientific Reports models the chances of a vaccine-resistant strain emerging in the near future. It warns a “danger zone” is when populations have reached a vaccination level of about 60 per cent. This is where the balance between resistance and growth suits the success of resistant mutations.
Delta’s high transmission makes this even more likely — the more virus circulating means more partially and fully vaccinated people will be infected. And that means more chances of vaccine resistance developing. …
“HIV changes four times more often than coronavirus. Influenza, two times more often,” Dr Turville says.
The ultimate Covid-19 spike protein needs seven changes to be brought together at the same time.
“In a little over a year, we’re looking at a little over 20 changes in Covid-19’s 30,000 building blocks,” he says.
“These are the ones that have stuck with it because they’re beneficial. But there would have been a lot of other experiments the virus has made with its progeny that have gone nowhere, or they’re not as fit as others.”
In information theory, we often considered an extreme case — given long enough, a bunch of monkeys banging away on typewriters will type the complete works of Shakespeare.
Because the current vaccines do not kill the virus, but merely protect us from severe symptoms while it breeds and mutates in our bodies, a fully vaccinated and infected world will have 7 billion vaccinated human Petri dishes all breeding up new versions of covid. So it’s only a matter of time before ultimate covid comes into existence.
Or maybe someone will hurry it along in a lab, in time for the next military games.