Delta’s not the only COVID-19 variant. It’s just the most dangerous.

Eleven COVID variants have been identified, and at least five of them have shown up in Indiana. The Indiana Department of Health classifies one of every 13 strains identified in the last month as “not variants of concern.” That categorization includes the original, unmutated strain. But it also includes the Epsilon variant first identified in California.

I-U School of Medicine infectious diseases specialist Cole Beeler says viruses are constantly experimenting with ways to make themselves spread better. “Variants are all competing for the same food source. And that’s us,” he says.

Sometimes, those experiments target a group of people successfully enough for researchers to identify them, but don’t have the staying power to compete with other, more powerful mutations.

Right now, Delta is muscling out other competitors. Beeler says the Alpha variant, the first to make a significant impact in Indiana, was 50-percent more contagious than the original virus. Delta is 50-percent more contagious than that. Beeler says both appear to pack a larger viral load, which also shortens the incubation period before symptoms arise.

Beeler says Delta’s more dangerous because it expands the pool of infected people, raising the odds some will become seriously ill. So far, Delta doesn’t appear to inherently cause more severe illness, but Beeler says future variants which amp up their potency instead of their infectiousness are possible.

Beeler notes one goal of the vaccination drive is to give the virus fewer chances to up the ante again. Beeler says if the virus has fewer opportunities to spread, there are fewer incubators for another round of more serious mutations.