The largest union of registered nurses in the country has slammed the Centers for Disease Control and Prevention’s latest mask recommendation for fully vaccinated citizens, claiming that the decision isn’t “based on science.”

National Nurses United cited eight concerns including a continued high number of COVID-19 cases, circulation of variants, and unanswered questions about vaccines.

Dr. Paul Calkins is IU Health’s associate chief medical executive and said while the CDC’s new guidelines are the correct medical decision, he’s unsure if they are the correct policy decision.

“The concern of course is that there is no way to tell a vaccinated person from an unvaccinated person,” Calkins said. “But it really is pretty science-based, what they did. The question, of course, really goes more about the implementation.”

Calkins said he will continue to wear his mask for personal safety.

Monroe County Health Administrator Penny Caudill addressed the same topic Friday.

“It doesn’t mean that if you’re fully vaccinated that you can’t wear your mask,” Caudill said. “And I know there are many people who are fully vaccinated who will continue to mask up in many situations.”

Caudill said people may be required to continue wearing masks in certain instances, such as entering federal or state properties, vaccination clinics, and federal office buildings.