People should stay away from vaping devices, the Centers for Disease Control and Prevention recommended Friday.

The CDC is currently investigating the spate of vaping-related illnesses that have popped up across the country in recent weeks. CDC officials are aware of 450 confirmed or suspected cases in 33 states.

“While this investigation is ongoing, people should consider not using e-cigarette products. People who do use e-cigarette products should monitor themselves for symptoms,” the CDC wrote in a news release.

The announcement comes on the same day that Indiana health officials confirmed the state’s first death from a vaping-related respiratory illness, bringing the national toll to three, after two such deaths in Illinois and in Oregon.

The CDC also said that it’s investigating a fourth death, but declined to say where.

The person who died in Indiana was an adult, but officials gave no other details, citing privacy laws. There’s also no indication of what the person may have been vaping.

“The tragic loss of a Hoosier and rising number of vaping-related injuries are warnings that we cannot ignore,” Dr. Kris Box, Indiana’s health commissioner, said in a statement.

Neither federal nor state health investigators have been able to pinpoint a brand, ingredient or substance behind the illnesses, but many suspect oils in vapes may play a role.

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