COVID-19 variant cases are on the rise in Texas. Here’s what you need to know.

Last winter, health experts worried about COVID-19 variants spreading quickly across the state, further overwhelming already crammed intensive care units. While health officials remain concerned about the potential for a wider outbreak fueled by more contagious variants, new case averages, hospitalizations and deaths are still trending down in Texas as the number of people fully vaccinated statewide has passed 25%.

Nationwide, the average weekly number of new COVID-19 cases has dropped in more than half of states as 29% of Americans are now fully vaccinated.

While COVID-19 started out as one strain, it has since spawned dozens of recorded mutations, said Benjamin Neuman, a virologist and professor at Texas A&M University.