In recent months, there's been a surge of reports about hundreds of people ending up in the hospital due to severe lung illnesses and other health problems after vaping -- and at least 34 people have died. It's clear we're just starting to understand the dangers of vaping.

E-cigarettes hit the US market about a decade ago, touted as a safer alternative to traditional tobacco cigarettes. However, they didn't really gain traction until 2015, when Juul Labs (then part of Pax Labs) debuted its discreet USB-size vaporizer and quickly became the industry leader.

The result was a spike in vaping, especially among teens and young adults, a segment of the population that, until then, had been using fewer tobacco products, according to the Centers for Disease Control and Prevention. In 2016, the Food and Drug Administration finalized a rule extending its authority to regulate all tobacco products, including e-cigarettes, the repercussions of which are still playing out today.

Below, we go through what's happened over the past year as health officials and the vaping industry try to adapt within this rapidly changing regulatory landscape.

Oct. 28, 2019 -- Juul reportedly laying off 500 jobs as vaping deaths rise to 34

Juul will be laying off 500 jobs by the end of the year, according to a report from The Wall Street Journal, citing sources. It comes as the CDC says there have been 34 deaths and 1,604 lung injury cases as of Oct. 22.

Oct. 17, 2019 -- Deaths reach 33, THC blamed for majority of cases

The CDC announced on Oct. 17 that as of Oct. 15, there have been 33 deaths across 24 states in the US. There have been 1,479 lung injury cases from every state except Alaska, as well as in the District of Columbia and in one US territory. 

The majority of the illnesses have been linked to vaping products containing THC, especially those bought off the street or from illicit dealers.

Speaking to a House Appropriations subcommittee on Oct. 16, a CDC official said the illness is "fatal or potentially fatal, with half the cases requiring intensive care," CNBC reported. EVALI, or "e-cigarette, or vaping, product use associated lung injury," is also getting worse as flu season hits, the report quoted CDC Principal Deputy Director Anne Schuchat as saying.

Oct. 9, 2019 -- Washington state reportedly bans sale of flavored vapes

The Washington state Board of Health has reportedly voted to temporarily ban the sale of nicotine and THC flavored vaping products two weeks after Gov. Jay Inslee asked for the emergency rule in an executive order. The board voted unanimously, Q13Fox reported, and the ban will go into effect this week and last four months.

The Washington Department of Health didn't immediately respond to a request for comment.

Oct. 7, 2019 -- Massachusetts reports its first vaping related death; nationwide deaths reach 18

Massachusetts health officials reported that a 60-year-old woman who vaped nicotine has died. This is the first vaping related death in the state, according to The Boston Globe. The Department of Public Health is still investigating what products she used and where they came from. The woman's identity wasn't disclosed to the public. 

As of Oct. 1, the CDC is reporting 18 deaths across 15 states.

Sept. 27, 2019 -- San Joaquin County DA launches investigation into Juul; FDA commissioner tweets about vaping investigation

Tori Verber Salazar, district attorney of San Joaquin County near the San Francisco Bay Area, told CNET her office has launched an investigation into vaping giant Juul because "too many minors are using" the company's products. One in four high school students are now vaping, she said, mentioning one minor who's in a coma with "the lungs of a 70-year-old man."

Juul marketed to youths through its colorful ads and fun flavors like bubble gum, Verber Salazar said. The company was "built on the heart and lungs and brain and damage" it's caused to the youth population with its highly addictive narcotic products, she added. Calling Juul's actions "organized criminal behavior," she said the DA's office is going to look into both civil and criminal actions against the company, including a potential class-action lawsuit.

Juul shares Verber Salazar's "concerns about youth vaping," a company spokesperson said in an emailed statement Friday afternoon. "We welcome the opportunity to cooperate and share information about our commitment to eliminate combustible cigarettes and our aggressive, industry leading actions to combat youth usage," the spokesperson added, pointing to Juul's shutdown of its social media accounts and cease-sale on flavored pods.

Also speaking Friday, Commissioner Ned Sharpless of the US Food and Drug Administration tweeted that the vaping investigation "is top priority" for the FDA, the Centers for Disease Control and Prevention and state and local health organizations. "We're working to identify what's making people ill & follow the supply chain to the source," Sharpless tweeted. "FDA's prepared to use the full extent of our authorities based on what facts emerge."

According to the CDC's latest update on its investigation into vaping lung injuries, "THC products play a role in the outbreak." The CDC's national report found that of 514 patients surveyed, 77% had used products that contained THC, 36% had used exclusively THC vapes, and 16% had used nicotine-only vapes.

Sept. 26, 2019 -- Vaping lung cases reach 805 with at least 12 known deaths, CDC says

According to the latest information from the US Centers for Disease Control and Prevention, the number of cases of the mysterious lung illness attributed to vaping has soared 52% over the last week, bringing the total number of cases to 805, CNBC reported. To date, 12 people have died and patients have been found in 46 states.

The deaths include two in California, two in Kansas and one each in Georgia, Florida, Illinois, Indiana, Minnesota, Missouri, Mississippi and Oregon. The median age of patients is 23 years old, and two thirds of patients are male.

Sept. 25, 2019 -- Juul CEO steps down as vaping company ceases all US advertising

Kevin Burns, who co-founded Juul, will be replaced by K.C. Crosthwaite, an executive for tobacco company Altria. Juul also said it would suspend all broadcast, print and digital advertising in the US and promised to "refraining from lobbying" the Trump administration on its proposal to ban flavored e-cigarettes.

Sept. 24, 2019 -- California warns of "sudden lung damage"

The California Department of Public Health released a health advisory that warns citizens of the "imminent public health risks posed by vaping any product." It said it's received reports of 90 people in California with a history of vaping being hospitalized "for severe breathing problems and lung damage" since June.

Two people have died in California, the state's public health department said. The advisory added that everyone should stop vaping "no matter the substance or source." If people continue vaping, they should never modify a vaping product, or buy one off the street, it said.

Vaping appears to be causing "sudden lung damage," the health department said. Symptoms that could be linked to vaping include coughing, chest pain, difficulty getting your breath, nausea, vomiting, diarrhea, abdominal pain, fatigue, fever and weight loss.

Teens and young adults make up almost half of the those hospitalized with breathing problems from vaping, according to the health department. And 30% of the people hospitalized in California had be treated with a mechanical ventilator -- in other words, they were put on life support -- in the intensive care unit.   

Sept. 20, 2019 -- Walmart discontinues the sale of e-cigarettes 

Citing "regulatory complexity" and "uncertainty" around e-cigarettes, Walmart said it'll stop selling the products, according to a new report from CNBC. Earlier this year, the company raised the required age to buy tobacco products to 21 and discontinued the sale of fruit and dessert nicotine flavors. 

Sept. 19, 2019 -- Vaping criminal probe announced by FDA as illnesses rise to 530

Health officials from the Centers for Disease Control said that the number of cases of vaping-related lung illnesses has risen to 530 across 38 states. As reported by The Washington Post, the Food and Drug Administration revealed a criminal investigation into the outbreak. Seven people have died from the illness so far. The FDA has collected more than 150 samples from patients across the country and are now analyzing them for the presence of cutting agents and other substances.

Sept. 16, 2019 -- Three confirmed cases of severe lung disease related to vaping in Washington

The Washington State Department of Health confirmed two new cases of severe pulmonary disease related to vaping, bringing the total number of confirmed cases statewide to three. Of the two new cases, one patient is in their teens, and the other is in their 20s. All three confirmed cases reported vaping prior to the onset of their illness, but the department has not yet identified a common product, device or additive among the three, though investigations are ongoing. 

"The symptoms of these patients match what the Centers for Disease Control and Prevention have asked all state and local health jurisdictions to be on the lookout for in regards to the nationwide investigation into this matter," Washington State Health Officer Kathy Lofy said in a press release. "This is now a state-wide outbreak."

Sept. 12, 2019 -- Photos emerge revealing severe lung damage, Juul continues ads despite FDA warning

A collection of photos obtained by Business Insider from doctors and researchers illustrate what are believed to be the severe effects of vaping-related lung damage. The images include those of a California teen who underwent surgery to remove a blister that collapsed his lung after he used a cannabis vape he bought at a concert. Other photos illustrate patterns noted by researchers, including inflammation, damage to the alveoli (or the lungs' air sacs), and particles of fat in lung tissues. The surgeons quoted in the article said they couldn't confirm that the injuries and illnesses were definitely caused by vaping.

Despite a warning letter from the US Food and Drug Administration last week, a Juul spokesman told CNBC the company will continue to run its "Make the Switch" ad campaign, which positions vaping as a safer alternative to cigarettes. The company is required to obtain FDA approval before asserting that a product is safer than cigarettes but hasn't submitted an application for such approval, CNBC said. 

Sept. 9, 2019 -- FDA calls out Juul for claiming vaping is safer than other tobacco products

The FDA has raised more concerns about Juul over some questionable marketing that suggested that Juul's vaporizer is safer than other tobacco products. What's worse, high school students testified before Congress claiming that a company rep told them that Juul is "totally safe."  

Sept. 6, 2019 -- Two more deaths and CDC warning

Health officials in Minnesota confirmed that a 65-year-old person died in August after a long hospitalization from severe lung injury. The person had a history of underlying lung disease, but the lung injury was associated with vaping illicit THC products. (THC is the component in marijuana that gets people high.) The lung injury progressed to other conditions, ABC 5 reported on Friday. The Minnesota Department of Health told the station that the state has had 17 patients to date who've been classified as confirmed or possible cases. An additional 15 cases are under investigation.

The first death in Los Angeles county related to vaping was also reported the same day by ABC 7. The county has reported 12 cases "of vaping-associated pulmonary injury" to date, according to its Department of Public Health. 

The CDC also released a statement about its investigations and said no single product is linked to all cases of lung disease. Many of the patients reported recent use of products containing THC while some reported using products with both THC and nicotine. A smaller group said they used nicotine only. 

Illinois Sen. Dick Durbin tweeted a letter to Ned Sharpless, acting commissioner for the US Food and Drug Administration, demanding action. Durbin said the FDA should send letters to all schools in America warning them of health consequences related to vaping. He also called on the agency to ban e-cigarette flavors other than tobacco and ban e-cigarette devices that haven't been approved by the FDA.  

"If Dr. Sharpless doesn't take action in the next 10 days, I plan to call for his resignation. Enough is enough," Durbin tweeted. 

Sept. 5, 2019 -- Indiana reports vaping-related death 

A third life was claimed by severe lung injury related to vaping, The Wall Street Journal confirmed. After news of the individual's death, federal health authorities urged people to stop using e-cigarette products while they investigate about 450 cases of the mysterious illness in 33 states.

Sept. 4, 2019 -- A second vaping-related death

Severe lung disease linked to vaping took another life, according to The New York Times. The unidentified person was hospitalized after vaping THC using a product bought at an Oregon recreational marijuana shop, the Times said. The patient was "otherwise healthy and quickly became very ill," a public health physician and lead investigator in the case told the paper. 

Aug. 30, 2019 -- CDC: Don't buy vaping products off the street, and don't modify them

The Centers for Disease Control and Prevention "took the unusual step" of issuing recommendations regarding vaping and e-cigarette products, The New York Times reported. The CDC's vaping recommendations cover the general public, clinicians and public health officials. Among the advice for the public: "Anyone who uses e-cigarette products should not buy these products off the street (e.g., e-cigarette products with THC, other cannabinoids) and should not modify e-cigarette products or add any substances to these products that are not intended by the manufacturer." The CDC also said, as it had done previously, that "e-cigarette products should not be used by youth, young adults, pregnant women, as well as adults who do not currently use tobacco products."

Aug. 29, 2019 -- FTC launches an investigation into Juul's marketing practices

The Federal Trade Commission has launched an investigation into whether Juul practiced deceptive marketing, including targeting minors and may seek monetary damages, according to a report from The Wall Street Journal.

Aug. 28, 2019 -- Juul CEO says respiratory illness cases are 'worrisome'

Juul CEO Kevin Burns calls the recent string of lung illnesses potentially linked to vaping "worrisome" and urges nonsmokers to avoid using Juul. "If there was any indication that there was an adverse health condition related to our product, I think we'd take very swift action," Burns said in a CBS This Morning interview.

Aug. 23, 2019 -- Illinois reports a patient dying after vaping

The Illinois Department of Public Health said a person who had "recently vaped and was hospitalized with severe respiratory illness" had died. The death may be the first tied to vaping in the US, according to the Associated Press.

Aug. 20, 2019 -- Juul Labs leaves Vapor Technology Association

Six days after the VTA issued a lawsuit against the FDA, Juul Labs announces that it won't renew its membership to the industry group, citing differences on "critical policy issues."

Aug. 19, 2019 -- Health officials report more than 150 people have been hospitalized

State and federal health officials report that 153 people -- many of them young adults -- across 16 states have been treated for respiratory issues that occurred after vaping.

Aug. 19, 2019 -- Juul Labs sued over marketing practices

A 19-year-old Juul user sues the company for targeting minors and using deceptive marketing practices, saying the practices led to his nicotine addiction. The lawsuit also names tobacco giant Philip Morris and its parent company Altria, a Juul investor.

Aug. 17, 2019 -- CDC opens probe into vaping-related lung disease

State and federal health officials team up to explore whether e-cigarettes caused severe pulmonary issues in 153 people (and counting).

Aug. 16, 2019 -- Investors still bullish on Juul Labs

Juul Labs raised another $325 million from investors, despite growing health and legal concerns, according to regulatory filings.

Aug. 14, 2019 -- Vaping industry group sues FDA

The Vapor Technology Association, which represents hundreds of vaping companies, files suit against the FDA to delay regulators' review of the e-cigarettes currently on the market.

Aug. 7, 2019 -- FDA says it's received 127 reports of vaping-related seizures

FDA releases a statement saying it's now received a total of 127 reports of seizure or other neurological symptoms, such as fainting or tremors, that occurred after vaping between 2010 and 2019.

July 26, 2019 -- WHO issues global tobacco epidemic report

In a report, the World Health Organization calls for more research and regulation of e-cigarettes and specifically names Juul as one of the new industry players that "continue to subvert tobacco control."

July 24, 2019 -- Facebook, Instagram restrict e-cigarette content

Facebook issues a new policy that will restrict sales of and limit content related to alcohol and tobacco products, including e-cigarettes, across Facebook and Instagram.

July 23, 2019 -- FDA launches anti-vaping ads to combat teen vaping

The FDA launches new anti-vaping commercials as part of The Real Cost, the agency's nearly $60 million smoking prevention campaign. In the TV ads, a street magician uses tricks to educate teens on the risks of using e-cigarettes.

July 12, 2019 -- E-cigarette marketing application submission deadline set

A US District Court judge in Maryland gave e-cigarette companies until May 12, 2020, to submit premarket tobacco applications to the FDA for approval.

June 25, 2019 -- San Francisco bans e-cigarettes

San Francisco, home to Juul's headquarters, becomes the first city in the US to ban the sale of e-cigarettes.

April 3, 2019 -- FDA announces investigation into potential link between seizures and vaping

The FDA notifies the public that it has received reports of people experiencing a seizure following the use of e-cigarettes.

March 27, 2019 -- Health experts sue FDA over delay of e-cigarette review

Seven public health and medical groups and several pediatricians file suit against the FDA for not following proper requirements when the agency gave e-cigarette companies more time to submit their products for review.

March 13, 2019 -- FDA restricts sale of flavored tobacco products

FDA issues new guidelines restricting the sale of most flavored tobacco products, including e-cigarettes, at convenience stores, gas stations and pharmacies. The FDA also asks that all e-cigarette manufacturers submit applications showing their products meet current regulations by Aug. 8, 2021.

Nov. 18, 2018 -- Juul Labs shuts down social media accounts

After the FDA expresses concern that Juul is luring in underage users, the company shuts down Facebook and Instagram accounts, and limits its Twitter presence to "non-promotional communications only."

Sept. 31, 2018 -- FDA inspectors seize documents from Juul Labs HQ

The FDA conducted an unannounced inspection of Juul Labs' San Francisco headquarters, seeking more information about the company's sales and marketing practices. Inspectors collected "over a thousand pages of documents," according to the agency.

Sept. 12, 2018 -- FDA calls teen vaping an "epidemic"

Dr. Scott Gottlieb, the FDA commissioner at the time, issues a statement calling teen vaping an "epidemic" and urges the e-cigarette industry to address the problem or risk having their flavored products pulled from the market.

Originally published Aug. 23, 2019 and updated as new developments occur. 

Note: The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives. 

CNET's Alison DeNisco Rayome, Rae Hodge and Sean Keane contributed to this report.