Does vaping increase COVID-19 risk?

Since the beginning of the COVID-19 pandemic, many have speculated that vaping could increase the risk of getting COVID-19 and experiencing more severe outcomes from the disease. The claims were grounded in little to no evidence, and almost none has emerged since.

The authors of a [California study|https://www.jahonline.org/article/S1054-139X(20)30399-2/fulltext#%20] claimed that their survey showed young vapers were five to seven times more likely than never vapers to test positive. It received a massive amount of media coverage. It also received scathing criticism and calls for retraction from longtime researchers in the field who cited [multiple methodological issues|https://pubpeer.com/publications/CEB008BBD48F89272321EB50092793]. A [large Icelandic study|https://www.laeknabladid.is/tolublod/2020/12/nr/7557] reported that the proportion of e-cigarette users was lower among patients with COVID-19 than in the general population of Iceland and that patients using e-cigarettes did not have more severe symptoms than other patients. A non-peer reviewed [UK study|https://www.medrxiv.org/content/10.1101/2020.12.01.20241760v1] found that vaping was not associated with self-reported Covid-19.

There is a considerable amount of evidence that current tobacco smoking is associated with a reduced chance of testing positive. Former smokers appear to face more serious outcomes than current or never smokers. Outcome data on current smoking are mixed.

https://onlinelibrary.wiley.com/doi/full/10.1111/add.15276

https://erj.ersjournals.com/content/early/2020/07/09/13993003.02144-2020

A [twitter thread|https://twitter.com/phil_w888/status/1279973073811197952] with links to hundreds of studies which report smoking status data of Covid-19 patients