As many as 1.3 million more teens have tried vaping this year compared to last year, according to the latest government-funded survey on teen nicotine use.

The survey, released Monday by the National Institute on Drug Abuse, found that 37.3 percent of high school seniors reported "any vaping during the past 12 months," up from 27.8 percent in 2017. Among eighth graders, 17.6 percent said they vaped during the last year, an uptick from 13.3 percent the year before.

"We know that these have been quite popular around youths for the past two years, but with data from 2018 the increases are really remarkable," said Dr. Wilson Compton, deputy director at NIDA.

More teens are vaping even as the Food and Drug Administration cracks down on e-cigarettes. Scott Gottlieb, who oversees the agency, has rolled out a series of proposals intended to curb teen vaping, including limiting access to flavored products.

Yet, there was good news elsewhere in the survey. Only 3.6 percent of high school seniors smoke traditional cigarettes, down from 22.4 percent about 20 years ago. Compton said that finding was a public health achievement, but cautioned that officials were concerned that teens would switch to traditional cigarettes as they got older. He pointed to a couple of studies that suggested an association between vaping and smoking.

But Gregory Conley, president of the American Vaping Association advocacy group, pointed to the trends reported in the survey to dispute the assertion that e-cigarettes were a gateway to smoking traditional cigarettes.

"No youth should use any nicotine or tobacco product, but it is indisputable that risk-seeking youth are better off experimenting with vaping products than tobacco cigarettes or other combustible products," he said. "Teenage cigarette smoking had stalled for several years prior to vaping coming to market, which was then followed by the record breaking declines in smoking once teens found different, less risky products to experiment with."

"At some point, professional fearmongers ... are going to have to examine the data and conclude that any 'gateway' effect from vaping to cigarettes is far outweighed by the number of teens displaced from ever smoking because of vaping," Conley said.

Gottlieb has said that he is open to vaping companies showing that their products are less harmful than traditional cigarettes and can help people quit. But he said that giving companies more leeway in regulations has come at the cost of more young people taking up vaping.

[Related: Juul to halt flavored e-cigarette sales to more than 90,000 stores as federal crackdown looms]

The survey released Monday is funded by a government grant to the University of Michigan at Ann Arbor, which has been running it ever since 1975 and records other types of substance use, from alcohol to opioids. Overall, 44,482 students in 392 public and private classrooms participated, meaning that any students who dropped out of school before senior year are not recorded. Students who are the heaviest users of drugs and alcohol, whether undergoing treatment at a facility or struggling with homelessness, are presumed to be left out of the findings.

Vaping opponents, including members of the public health sector, have long charged that e-cigarettes target teens because they come in multiple flavors intended to mimic fruits or desserts. Defenders of the flavors say that adults need an alternative that tastes nothing like traditional cigarettes to get them to stop smoking.

The FDA plans to ban the sale of certain flavored e-cigarettes in convenience stores and gas stations. This would mean that certain flavors can be sold only in specialty vaping shops. The FDA will also require age verifications on websites where the devices are sold.

The actions have caused alarm among conservatives who point to the Trump administration's otherwise deregulatory agenda, and to vaping organizations who argue that they will diminish progress made on smoking regular cigarettes.

The data from the latest study leave several questions unanswered about vaping among teens. For instance, when a teen says he or she has tried e-cigarettes during a lifetime, during the past year, or during the past month, it's not clear how frequently. It could mean that a teen experimented once, or that he or she use several times a day.

"We need to understand in more detail," Compton said, but added that the data from the survey were still helpful to understanding the issue because, "You don't become a regular user without experimenting."

He stressed as well that more data would be important to understanding how to cater public health messages and that it was important not to exaggerate findings.

"When you exaggerate with teens, they no longer take messages seriously," he said.