Why You Shouldn’t Panic About ‘Deltacron’ Yet

Last week it was flurona. This week it’s something called “deltacron.” We’re primed to go “oh shit” when we hear about a new variant, because we’ve been burned by quite a few of them by now. But the scary names outnumber the things we actually need to be scared of.

Not long ago, we were warned about “delta plus.” That fizzled out. On the other hand, Delta was real, and its spike was particularly bad and has not yet gone away. Omicron is real, and is definitely still a problem. So how do we know which variants to worry about?

I’ll give you a big clue: The time to panic is not when somebody gives a virus a catchy new name. The time to panic is when a variant makes it onto the World Health Organisation’s “Variants of Concern” list. Currently, that list has five entries: Alpha, Beta, Gamma, Delta, and Omicron. (There is also a second list, the Variants of Interest, which currently just contains Lambda and Mu. A variant might start as a VOI and get upgraded to a VOC.)

Why variants make headlines even when they’re not a big deal

There are two reasons not to panic too early. One is that variants have to compete against each other in the real world. This is natural selection in action: If a variant isn’t good at reproducing itself, it’s just not going to get very far. Remember, what usually makes the variants of concern so concerning is that they’re more transmissible than what came before. Delta is just easier to catch than original flavour COVID. Omicron might be even more transmissible than Delta. So if there’s a new variant that looks scary, but it has trouble spreading itself around, it’s unlikely to ever be much of a problem.

But here’s the other reason: Sometimes the new scary name doesn’t even refer to a real virus. We just went through this last week, remember? A few people caught COVID and the flu at the same time, and suddenly there were a hundred headlines about “flurona.”

Flurona is not a hybrid virus or a unique threat, just an occasional, unfortunate coincidence. Doctors and scientists should certainly be paying attention to co-infections, for example in case co-infection needs special treatment. But it’s not time to panic.

And that brings us to deltacron, which looked at first like it might be an actual hybrid between two COVID viruses. Some labs in Cyprus reported that they found RNA sequences that included the signature mutations of Delta and of Omicron. But experts are sceptical.

“This is almost certainly not a biological recombinant of the Delta and Omicron lineages,” Jeffrey Barrett, an expert in COVID genomics, told the UK’s Science Media Centre. He points out that the supposed mutation lines up with a known technical issue that can occur in the testing process, causing the superficial appearance of a hybrid.

Other scientists have pointed out that the new deltacron sequences don’t fit anywhere sensible on the family tree of all the COVID variants. If Delta and Omicron really had come together in a freak accident, and now 25 people are infected with this new virus, you would expect all 25 samples to look similar to each other, and to appear next to each other on the big viral family tree. They don’t. What most experts see in this data is a strong implication that there was contamination in the lab, and that the contamination showed up in those 25 otherwise very different samples.

Great example. H/T: @Alexis_Verger

Left: Recombination with variants, the sequences are found in a cluster. ???? https://t.co/6itQ1hJ81Y

Right: “Deltacron.” With contamination, the distribution is found everywhere. ???? https://t.co/6itQ1hJ81Y pic.twitter.com/dWsLEDtMfn

— Chise ???????????????? (@sailorrooscout) January 9, 2022

So deltacron isn’t real? Well, probably not. The team that first identified the new sequences says they still think they found something real, and it will take more research to figure out for sure what is going on. But even if it turns out there really is a deltacron, we don’t yet have any reason to believe that it’s an unusually special or dangerous virus. If it is, we’ll know that soon. No need to worry before there’s any evidence that it’s worth worrying about.