After eight weeks of declining cases statewide, coronavirus cases and the positivity rate increased last week in Kentucky, the state’s public health commissioner, Steven Stack, announced Thursday at a virtual news briefing.

A large majority of cases have been in unvaccinated Kentuckians.

Kentucky has confirmed 26 cases of the delta variant of COVID-19, which is spreading quickly throughout the United States, Gov. Andy Beshear said. The state’s public health department has not yet determined what percentage of new cases are the Delta variant.

“Unvaccinated people who won’t get the vaccine and aren’t wearing masks at this point, ought to assume in their risk calculation that they are going to get COVID of some sort,” said Beshear, a Democrat. “We’re in a better position than probably all but two of our surrounding states but we still want people to get vaccinated.”

It is too early to tell if the state will reinstate its mask mandate that ended on June 11, Beshear added. Masks are still required on public transportation, in long-term care facilities and other locations that serve the “most vulnerable.”

“The delta variant is two and a half times or so more effective and spreading, which means that if it gets in your community, it’s going to spread real fast. That’s why it’s growing so quickly, and it can hurt people,” Stack explained. “The single thing you can do to protect yourselves or protect all of us is to get vaccinated.”

He said parents should ensure their children are vaccinated before summer sports practices and the upcoming school year, calling that a step to prevent infection and avoid the possibility of quarantining a large number of team members.

“Here’s the bottom line for students, parents and coaches: if you want to stay safe and on top of that, play sports, the single best thing you can do is go out and get vaccinated,” Stack said.

Kentucky reported 337 confirmed coronavirus cases and three virus related deaths Thursday. The state’s positivity rate is 2.92%, up from 1.99% last Thursday. The test positivity rate is an indicator of the extent of the spread of the virus. If the rate is less than 5% for two weeks and testing is widespread, the virus is considered under control, according to the World Health Organization.