There May Be Two Coronavirus Strains—One More Lethal Than The Other

According to Chinese scientists and a new study, we’re not fighting a single strain of coronavirus COVID-19—we’re actually fighting against two versions. They’ve dubbed the different versions the L strain and the S strain. Seventy percent of people, according to the scientists, have caught the L strain, which is the deadlier and newer version. But, the S strain, which is ancestral (meaning it dates back to the original spread of the virus), is gaining steam, and it’s not nearly as lethal as the L strain.

It’s a Small Study

The study, published in the National Science Review scientific journal, is admittedly small, with only 103 samples tested. But, they said, it definitely showed two strains.

“Whereas the L type was more prevalent in the early stages of the outbreak in Wuhan, the frequency of the L type decreased after early January 2020,” the study says, reported by The Daily Mail. “Human intervention may have placed more severe selective pressure on the L type, which might be more aggressive and spread more quickly. On the other hand, the S type, which is evolutionarily older and less aggressive, might have increased in relative frequency due to relatively weaker selective pressure.”

Not Everyone Agrees

The scientific community, though, doesn’t necessarily agree with the study. The University of Leeds’ Dr. Stephen Griffin told The Daily Mail that it’s common for viruses like this to change and adapt throughout their lifecycle. Plus, he says, there isn’t enough evidence to say if one strain is more lethal than the other.

FlyerTalkers are also quick to point out that the data behind these findings is lacking, and note it might be a good opportunity for scientists to do some virology testing.

“A significant minority of isolates from outside Wuhan are S strain,” one FlyerTalker said. “However, although the authors make predictions about relative severity, there’s no actual data to support that…all we can say is that there are two strains, and the ancestral one is actually more common outside Wuhan.

“However, this would be an excellent place for virology labs working with SARS-CoV2 to test the hypothesis…of whether one or the other is either more virulent or transmissible etc. The authors don’t make an unreasonable conjecture: that with more stringent control measures, there is selection pressure for a strain that causes milder symptoms…but that’s not actually derived from data. And the L strain is still the more prevalent (70% of samples) overall, even outside Wuhan.”