U.S. health officials have revised downward the number of cases of a severe lung injury linked to vaping, from more than 450 cases cited last week to the total of 380 cases announced late Thursday.

The decrease is due to the exclusion of “possible” cases, the U.S. Centers for Disease Control and Prevention explained. The new case total — which includes cases either confirmed or “probable” — have occurred across 36 states and the Virgin Islands, the CDC said in a statement.

Some cases have proven fatal. “Six total deaths have been confirmed in six states: California, Illinois, Indiana, Kansas, Minnesota, and Oregon,” the CDC noted.

The reason behind these illnesses and deaths remains uncertain, but a leading culprit at this point is an oily chemical called vitamin E acetate, according to the CDC.

The oil is derived from vitamin E, which is found in vegetable oils, nuts and seeds, and leafy green veggies. Vitamin E acetate is available as a dietary supplement and skin treatment.

When vaped and inhaled, this oil can harm lung cells, experts say.

Illnesses and investigations

“The focus of our investigation is narrowing and that’s great news, but we’re still faced with complex questions in this outbreak that will take time to answer,” Ileana Arias, acting deputy director of non-infectious diseases at the CDC, said during a Sept. 6 media briefing.

In the meantime, the CDC urges people to not use e-cigarettes until more is known about what’s causing these lung injuries. The American Medical Association has issued a similar warning.

“While this investigation is ongoing, people should consider not using e-cigarette products,” said Dr. Dana Meaney-Delman, the incident manager in charge of the CDC’s response to this health crisis.

According to Meaney-Delman, many patients in cases reported nationwide said they had also recently used “THC-containing products, and some reported using both THC- and nicotine-containing products. A smaller group reported using only nicotine products,” she added.

“People who do use e-cigarette products should monitor themselves for symptoms such as cough, shortness of breath, chest pain, nausea and vomiting, and promptly seek medical attention for any health concerns,” Meaney-Delman advised.

Action by White House

As concern grows over the outbreak of lung illnesses tied to vaping, the Trump administration on Wednesday said it would move to ban flavored versions of e-cigarettes.

Vaping is harming young people and “we’re going to have to do something about it,” President Donald Trump said at the Oval Office, The New York Times reported. He was flanked by Alex Azar, the secretary of Health and Human Services, and Dr. Ned Sharpless, the acting Food and Drug Administration commissioner.

Trump noted that he and his wife Melania have a teenaged son, Barron, and Melania “feels very strongly” about the vaping issue.

Azar told reporters that details of a plan to phase out flavored e-cigarettes from the market will be announced over the next few weeks. In a tweet, he added that “new provisional data show that youth use continues to rise rapidly, and we will not stand idly by.”

These days, U.S. teens are more likely to vape than to smoke, according to the U.S. National Institute on Drug Abuse. Among high school seniors, 16% say they used e-cigarettes in the past month, while only 11% smoked.

The White House’s move comes after similar legal attempts by states to curb an enormous surge in teen vaping.

This week Michigan became the first state to ban flavored e-cigarettes, which come in candy, fruit and other enticing flavors attractive to youth.

And earlier this year, San Francisco became the first major city to ban e-cigarette sales altogether. Juul Labs, the leading maker of vaping products, is challenging that ban via a ballot initiative set to go to voters in November.

An all-out ban?

One lung expert says the White House’s proposed ban on flavored e-cigarettes doesn’t go far enough, however.

“There is no guarantee of safety with any vaping, including the commercially sold nicotine products and devices,” said Dr. Len Horovitz, a pulmonary specialist at Lenox Hill Hospital in New York City.

“All vaping should be stopped immediately in view of the increasing number of reports of illness and death from vaping,” Horovitz added. “Chemicals so far implicated in vaping-related lung issues include propylene glycol, glycerin, diacetyl flavorings, and vitamin E. There may be other chemicals as yet unidentified.”

The Trump administration has faced mounting political pressure to do something about the vaping issue. Last week, Senator Dick Durbin, Democrat of Illinois, said he would ask for Sharpless to resign his post at the FDA if flavored e-cigarettes were not removed from the market, the Times reported.

And on Monday, billionaire philanthropist and former New York City Mayor Michael Bloomberg announced he was donating $160 million to help further a ban on flavored e-cigarettes.

More information

Visit the Center on Addiction for more on the dangers of vaping.