The number of confirmed or suspected severe lung illnesses linked to vaping has now climbed to 805 cases across 46 states and the Virgin Islands, U.S. health officials reported Thursday.
There have also been 12 confirmed deaths in 10 states - California (2 cases), Florida, Georgia, Illinois, Indiana, Kansas (2 cases), Minnesota, Missouri, Mississippi and Oregon, officials added. That's nearly a doubling of fatalities compared to the seven deaths reported a week ago.
Unfortunately, officials still don't know exactly what is triggering these lung injuries.
"Although the investigation continues, no consistent e-cigarette or vaping product, substance, additive or brand has been identified in all cases, nor has any one product or substance been conclusively linked to lung injury in patients," Dr. Anne Schuchat, principal deputy director of the U.S. Centers for Disease Control and Prevention, said during a media briefing held last week.
The U.S. Food and Drug Administration now has more than 150 vaping product samples tied to these cases, and is analyzing them for any potential clues, Mitch Zeller, director of the FDA's Center for Tobacco Products, said at the same meeting.
"FDA is analyzing these samples for the presence of a broad range of chemicals," Zeller said.
The investigation has been hampered by the fact that there are so many different vaping products on the market being used in many different ways, Schuchat and Zeller explained.
There's also the possibility that some people have been sickened by exposure to more than one type of product, Schuchat said.
One potential culprit is an oily chemical called vitamin E acetate. Vitamin E acetate is typically available as a dietary supplement and skin treatment, and it continues to be found in some of the samples, Zeller said.
But Zeller added that "our laboratory analysis continues to show a mix of results. There's no one compound, ingredient, constituent - including vitamin E acetate - that's showing up in all of the samples tested."
Nearly three-quarters of the people who've developed lung injury from vaping are male, Schuchat said, and more than half the cases are in people younger than 25.
Symptoms include cough, shortness of breath and chest pains. Some patients have had so much trouble breathing that they wind up on oxygen, and in extreme cases placed on a mechanical ventilator.
"Until we know more, if you are concerned about these specific health risks, CDC recommends you not use an e-cigarette or vaping product," Schuchat said.
The fallout from the ongoing outbreak of illnesses has hit the vaping industry hard.
On Wednesday, vape device maker Juul Labs said it is stopping all print, digital and television advertising, and its CEO, Kevin Burns, is stepping down.
Juul, by far the largest vaping products maker in the United States, also said it will not fight a proposed nationwide ban on flavored e-cigarettes put forward earlier this month by the Trump administration, the Associated Press reported.
K.C. Crosthwaite, an executive from Altria, will replace Burns. Tobacco giant Altria owns a 35% share of San Francisco-based Juul.
In a statement, Crosthwaite alluded to "unacceptable levels of youth usage and eroding public confidence in our industry," the AP said.
"We must strive to work with regulators, policymakers and other stakeholders, and earn the trust of the societies in which we operate," Crosthwaite added. "That includes inviting an open dialogue, listening to others and being responsive to their concerns."
The news from Juul came a day after testimony on Capitol Hill regarding the expanding number of cases of a sometimes fatal vaping-linked lung illness.
In her testimony before a congressional subcommittee, the CDC's Schuchat told lawmakers that "we are seeing more and more cases each day."
The situation has also spurred the Trump administration to call for a ban on flavored e-cigarettes. New York and Michigan have already put restrictions on the sale of vaping products and retail giant Walmart announced last week that it is pulling all e-cigarette products from its shelves.
And on Tuesday, Massachusetts stopped the sales of all vaping products for four months. Rhode Island is also planning to ban flavored e-cigarettes.
Giving the new health risks, Schuchat advised that former smokers who now vape should ask their doctor about using a nicotine patch or gum instead and not contemplate a return to smoking.
Health officials particularly warn against buying any vaping products off the street, especially if they've been laced with THC, the compound in marijuana that gets you high, Zeller said.
But again, THC products have not been involved in all the cases, Schuchat said. Some patients have used products containing THC and others containing nicotine, while some have only used nicotine products.