The new report, published Friday by the Centers for Disease Control and Prevention, comes from interviews with 86 confirmed and probable patients with the illness in IL and Wisconsin, the states which first reported the cases.
To date, the state has reported four cases of serious injuries related to vaping in individuals between 18 and 34 years of age.
Public health officials in Georgia and Florida reported two vaping deaths this week, bringing the nationwide total to 11.
Based on initial data from certain states, the CDC had said that most patients have reported a history of using e-cigarette products containing tetrahydrocannabinol or THC, the chemical responsible for most of marijuana's psychological effects.
Also participating in the call were health officials from Wisconsin as well as IL, which has one of the highest numbers of lung illness cases in the country.
In Illinois and Wisconsin, patient interviews revealed more about what they had been vaping.
Vitamin E acetate has been found in THC products taken from sickened patients and tested by state labs and the FDA's forensic lab, officials have said.
In a report published Friday, CDC and state investigators were careful to note that no one type of vaping product was involved in all cases.
No single ingredient or additive has been implicated, . but most of the products in question are believed to be from the black market or include THC, . the psychoactive ingredient in marijuana.
The department said it is working with local, state and national agencies to find cases and figure out the exact source.
"CDC has made it a priority to find out what is causing this outbreak of lung injuries and deaths and we're making progress", CDC Director Robert R. Redfield said in a news release. The fact that those who quit vaping may return to smoking.
Updated: Two vaping-related deaths in Oregon.
The study concludes that more than six percent of young Canadians, aged 15 to 24, use e-cigarettes within the month; 23 percent of which reported to have used an e-cigarette everyday.