Hundreds of mysterious illnesses and several deaths linked to vaping have revealed to health officials, doctors and researchers how little they know about what these chemicals do to the lungs.

As director of the Adolescent Substance Use and Addiction program at Boston Children's Hospital, Dr. Sharon Levy has seen the effects of vaping on teens firsthand. In her clinic, she's helped treat patients whose lives are falling apart, all because of vaping.

Vaping doesn't necessarily refer to a single substance. The health effects run the gamut from addiction to severe respiratory illnesses.

NBC News spoke to Levy about vaping and current spate of illnesses.

Is vaping nicotine more addictive than smoking cigarettes?

Simply put, vaping refers to inhaling a vaporized form of a chemical — usually nicotine or THC, the psychoactive ingredient in marijuana. Nicotine or THC is dissolved in a solution, and that solution is put into a device that heats it up into a gas that can be inhaled.

But even though the active ingredient in both traditional cigarettes and e-cigarettes is the same, the effects of nicotine from these products can be very different. That’s because the modern vapes, including Juuls, make it possible to inhale nicotine faster than you can with a traditional cigarette. Vapes can get a much higher dose of nicotine into the body, and to the brain, very quickly. The higher dose makes a big difference.

When it comes to addictive substances, the dose — and how quickly that dose gets into your body — really does matter. Take amphetamines, for example. A low dose of amphetamine is a very effective medication for treating ADHD. But in high doses, amphetamines are an illicit drug called “speed." Even though the molecule is exactly the same, at different doses, it has very different effects.

The same is probably true for nicotine, which, like amphetamine, is also a stimulant, but there are a lot of unknowns. That’s one of the real problems — experts have generally approached cigarettes and e-cigarettes the same, not fully appreciating the potential difference in dose. As a result, we’ve been assuming that the brain impacts from using e-cigarettes will be the same as traditional cigarettes, but that in fact might not be true.

What about vaping THC?

It’s the same story for THC. So-called dab pens and other devices used to vape THC are often highly concentrated. Vaping THC is not the same thing as smoking marijuana — instead, you’re inhaling THC that’s been extracted from the plant, and then delivered at a much higher dose. Those high doses are more likely to lead to acute psychotic reactions and other mental health problems that are seen in people who use THC.

Are new approaches needed to treat vaping addiction?

Because these products are so new, there’s no research on them — and no research on treatment. We’ve approached treatment using the general principles of addiction medicine and what we know about cigarettes as a starting point. But you can’t use the exact same approach, because the products are different, the dosages are different, and the problems are different. Many adolescents who are vaping don’t know about the dangers of using high doses of nicotine. Parents and teens may think that vapes allow users to get the pleasure of smoking without the health risks. The effects of these higher doses of nicotine are just not part of the public conversation.

Another big question is how nicotine affects the developing brain. Teen smoking is nothing new, but even for regular cigarettes, there aren’t many studies on what that nicotine exposure does to the developing brain. It’s likely that the dosage of nicotine from a cigarette would have a pretty minimal impact, but does the higher doses found in e-cigarettes change things? That’s a major area of concern.

What about flavored e-cigarettes?

Flavored e-cigs have been in the spotlight in recent weeks, with the Trump administration moving to ban the sale of all flavors except tobacco, and states taking action as well. Mint, mango, 'Nilla wafer, s’mores, cotton candy and strawberry are just a few of the many kid-friendly flavors added to e-cigarettes.

There are a number of problems with flavored e-cigs. The biggest is that they’re incredibly enticing to kids. In my clinic, many kids say they started vaping because they were curious about tasting the various flavors. Indeed, according to preliminary data from the Department of Health and Human Services, in 2019, more than a quarter of high school students admitted to using e-cigarettes, and the majority cited fruity and minty flavors.

The flavors also make vaping more palatable, by masking the actual taste of the chemicals being inhaled. And that’s what companies want — to make it easier for people to get the nicotine into their bodies.

The other big issue with flavors is that they’re completely unregulated. Nobody knows what they’re going to do to the lungs.

Ultimately, banning flavors could help reduce the number of kids who start vaping. Without flavors, there’s less incentive for teens and other people to try vapes.

Could the flavor ban curb the lung illnesses?

The flavor bans could, in the long run, help improve the situation with the spate of lung illnesses, too — it’s possible that some of the flavoring chemicals can hurt the lungs. And of course if fewer people vape, there will be fewer illnesses.

But the flavor bans won’t have any impact on THC vapes, which are not regulated by the FDA at all, and with the exception of a few states, operate in a completely unregulated industry.

Many of the people who have gotten very sick from vaping reported vaping THC. That doesn’t mean it’s the THC caused the lung disease — it’s much more likely that the problem stems from the various solutions and additives in the liquids.

Indeed, for both nicotine and THC vapes, the chemicals are always dissolved in some sort of solution, and the manufacturers don’t have to tell us what's in there. Many products contain food additives that are generally considered to be safe ... as food additives. There's a big difference between introducing a substance into the digestive tract versus the lungs.

Another question is, why now? It's not really clear to me. These products have been available for a while, but the vaping illnesses appear to be new. It's possible that the illnesses have been here all along, but we didn't recognize them until someone put it together and tied the lung disease to vaping. But it's also possible that there are some new toxic things out there, and people are inhaling them straight into their lungs.

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