Priority 20 from the Electronic Cigarettes PSP

UNCERTAINTY: What are the health effects of vaping for never-smokers and ex-smokers? (JLA PSP Priority 20)
Overall ranking 20
JLA question ID 0087/20
Explanatory note  Not available for this PSP
Evidence

 None identified

Health Research Classification System category  Generic health relevance
Extra information provided by this PSP
Original uncertainty examples For non-smokers/never-smokers, who start to use vapor-products - what could the health consequences be - compared to initiation of smoking instead? this is not referring to passive vape. I am thinking of one person in particular who wanted to know if it would be harmful for him to start vaping. He is an ex-smoker (quit for over 30 years) but still misses smoking.   
Submitted by 5 x Healthcare Professionals, 7 x Patients
PSP information
PSP unique ID 0087
PSP name Electronic Cigarettes
Total number of uncertainties identified by this PSP. 52 (To see a full list of all uncertainties identified, please see the detailed spreadsheet held on the JLA website)
Date of priority setting workshop 20 September 2019