May 13, 2020

Stanton A. Glantz, PhD

Reduce your risk of serious lung disease caused by corona virus by quitting smoking and vaping

Updated May 12, 2020

When someone’s lungs are exposed to flu or other infections the adverse effects of smoking or vaping are much more serious than among people who do not smoke or vape.

Smoking is associated with increased development of acute respiratory distress syndrome (ARDS) in people with a risk factor like severe infection, non-pulmonary sepsis (blood infection), or blunt trauma.   People who have any cotinine (a metabolite of nicotine) in their bodies – even at the low levels associated with secondhand smoke – have substantially increased risk of acute respiratory failure from ARDS (paper 1, paper 2, paper 3). 

The recent excellent summary of the evidence on the pulmonary effects of e-cigarettes reported multiple ways that e-cigarettes impair lungs’ ability to fight off infections:

Effects on immunity

Reporting of respiratory symptoms by e-cigarette users suggests increased susceptibility to and/or delayed recovery from respiratory infections. A study of 30 healthy non-smokers exposed to e-cigarette aerosol found decreased cough sensitivity.82 If human ciliary dysfunction is also negatively affected, as suggested by animal and cellular studies,83 the combination of reduced coughing and impaired mucociliary clearance may predispose users to increased rates of pneumonia. Exposure to e-cigarettes may also broadly suppress important capacities of the innate immune system. Nasal scrape biopsies from non-smokers, smokers, and vapers showed extensive immunosuppression at the gene level with e-cigarette use.84 Healthy non-smokers were exposed to e-cigarette aerosol, and bronchoalveolar lavage was obtained to study alveolar macrophages.46 The expression of more than 60 genes was altered in e-cigarette users’ alveolar macrophages two hours after just 20 puffs, including genes involved in inflammation. Neutrophil extracellular trap (NET) formation, or NETosis, is a mode of innate defense whereby neutrophils lyse DNA and release it into the extracellular environment to help to immobilize bacteria, a process that can also injure the lung.85 Neutrophils from chronic vapers have been found to have a greater propensity for NET formation than those from cigarette smokers or non-smokers.57 Given that e-cigarettes may also impair neutrophil phagocytosis,86 these data suggest that neutrophil function may be impaired in e-cigarette users. [emphasis added]

Studies in animals reinforce and help explain these human effects:

Two weeks of exposure to e-cigarette aerosol in mice decreased survival and increased pathogen load following inoculation with either Streptococcus pneumoniae or influenza A, two leading causes of pneumonia in humans.97 Furthermore, the aerosol exposure may lead to enhanced upper airway colonization with pathogens and to virulent changes in pathogen phenotype, as shown with Staphylococcus aureus.98 99 Thus, although more studies are needed, the animal data suggesting that vaping leads to an increased susceptibility to infection would seem to correlate with the population level data in young adult humans, whereby vapers have increased rates of symptoms of chronic bronchitis.23 [emphasis added]

A meta-analysis of the relationship between smoking and influenza found that smokers were more likely to be hospialized and admitted to the ICU.

As of April 28, 2020 there were 19 peer reviewed papers that had data on smoking and COVID disease progression, 17 from China, 1 from Korea, and 1 from the US.  Our peer reviewed meta-analysis of these 19 papers found that smoking was associated with more than a doubling of odds of disease progression in people who had already developed COVID. 

The WHO has also conluded that, " smokers are more likely to develop severe disease with COVID-19, compared to non-smokers" and provides a nice discussion of how smoking increases risk of COVID-19 by increasing the risk of heart, lung, and other diseases.

Dr. Nora Volkow, director of the National Institute on Drug Abuse, posted an article on her blog "COVID-19: Potential Implications for Individuals with Substance Use Disorders," that stared off by saying

As people across the U.S. and the rest of the world contend with coronavirus disease 2019 (COVID-19), the research community should be alert to the possibility that it could hit some populations with substance use disorders (SUDs) particularly hard. Because it attacks the lungs, the coronavirus that causes COVID-19 could be an especially serious threat to those who smoke tobacco or marijuana or who vape.

She goes on to address other drug use and how COVID-19 could interact with them, including noting that

Vaping, like smoking, may also harm lung health. Whether it can lead to COPD is still unknown, but emerging evidence suggests that exposure to aerosols from e-cigarettes harms the cells of the lung and diminishes the ability to respond to infection. In one NIH-supported study, for instance, influenza virus-infected mice exposed to these aerosols had enhanced tissue damage and inflammation.

The whole blog post is worth reading.

In addition, an article in Scientific American, "Smoking or Vaping May Increase the Risk of a Severe Coronavirus Infection," summarizes how smoking and vaping affect the lungs and the immune system that is consistent with the view that using these products increases the risk of infection and worse outcomes.  CNN also has a good story, "How smoking, vaping and drug use might increase risks from Covid-19."  KQED/NPR reports on a young man who developed COVID that may have been aggrevated by his vaping.  Fortunately, he recovered and has now stopped vaping.

The New York Times has a good story reporting that the Massachusetts AG put out an advisory urging people to stop smoking and vaping and pointed to resources to quit.

CDC, FDA, the Surgeon General, state health departments and everyone (including comedians, such as John Oliver who spent his whole show on the issue last weekend) working to educate the public on how to lower risk of serious complications from covid-19 should add stopping smoking, vaping, and avoiding secondhand exposure to their list of important preventive measures.

This would also be a good time for cities, states private employers and even individual families to strengthen their smokefree laws and policies – including e-cigarettes -- to protect nonsmokers from the effects of secondhand smoke and aerosol on their lungs and to create an environment that will help smokers quit.

The California Department of Public Health has information on smoking, vaping and COVID here, as does the California Smokers' HelplineTrinity Health is also urging people to stop smoking to protect against COVID-19.  FDA has said that vaping and smoking could increased COVID risks.  CDC lists smoking as one of the risk factors for COVID-19 because smoking depresses immune function.

The Ontario Tobacco Research Unit has prepared a good two-page summary of the evidence and recommendations from various sources and authorities; it is available hereTobacco Control also has a list of smoking and COVID resources here.

UCSF has added smoking and vaping nicotine and cannabis to COVID-19 triage protocol.  Doing so will both improve patient care and, over the longer term, provide important information needed to quantfy how smoking and vaping impact COVID risks. 

Not surprisingly, the pro-vaping lobbying organization CASAA does not agree with me or the other cited authorities; you can read their perspective here

There has also been widespread press coverage of a couple papers suggesting that smoking and nicotine may be protective against COVID.  The University of Bath released an excellent assessment of these studies describing their serious problems with these studies, including the fact that one isn't even a "study;" it's just a hypothesis.  As they note, one of the authors also has longstanding ties to the tobacco industry. (The tobacco companies have a long history of promoting the idea that nicotine has health benefits [Study 1, Study 2].)  Even if nicotine -- as hypothesized -- has some benefits, that is really different from cigarette smoke (or e-cigarette aerosol) which has thousands of other things in it.  Those compounds likelyoverwhelm any "benefits" of nicotine.  Salon.com also has an excellent article, "Here's how that rumor that smokers can't get COVID-19 got started."  The title says it all.

FREQUENTLY ASKED QUESTIONS

A lot of people have asked questions or sent comments on this post.  I have responded to the people who asked unique questions.  (I have not posted testimonials, offers of products, or questions for personal medical advice.)  To present this material in a more accessible form, I organized these issues as a FAQ.

I will add to this as new issues come up.

I smoked for a long time before I quit.  Are the risks still there?

The damage done to your respiratory system’s ability to fight infections starts recovering immediately after you stop smoking. 

You are no longer bathing your lungs in toxic chemicals, so you are better off.  The cilia (liitle hairs that move foriegn particles out of your lungs so you can cough them out) are recovering.  CDC has a good summary of what happens after you quit, which is available here.

Will my lungs recover after I stop vaping?

While I have not seen similar studies for how quickly your respiratory tract recovers after you stop vaping, the same recovery likely happens after stopping smoking.

I quit smoking 2 months ago and am currently using 2 mg nicotine lozenges. Should I now also stop those because of the nicotine?

The effects of concern are due to the inhaled aerosol, not nicotine in your blood (which is what the NRT affects).  You should eventually wean yourself off the NRT (because it has other effects), but I would stay on the NRT until you are sure that you are past smoking.

I recently quit Juuling and now am scared since I am using nicotine replacement therapy, patches or gum. Is the nicotine in them just as dangerous as the Juul?

You are much better off quitting Juul (or any other e-cigarette) than containing to vape.  You are not inhaling the untrafine aerosol that Juul and other e-cigs -- and cigarettes -- deliver to your lungs.

Once you are sure you are de-addicted, you should get off the NRT, but stay on it as long as you need to avoid Juul.  Counselling helps.  State quitlines are available for free, which you can reach through 1-800-QUIT NOW.  Many also provide medications to help when appropriate.  Truth Initiative has a texting service targeted at Juul.

Does exhaled cigarette smoke spread corona virus?

This is not something that has received much study.  The one study that looked at flu didn't find that smokers shed more virus.  No one seems to have studied vaping.

Having said that, it is now clear that some of the coronavirus is in the exhaled aerosol, so the presence of the exhaled smoke or e-cigarette aerosol provides at least some indication of where the exhaled virus might be.

How do Juul e-cigarettes compare with other kinds of e-cigarettes in terms of infection risks?

As far as I know, no one has yet studied Juul particularly in terms of effects on pulmonary immunity and inflammation (although I have not done a comprehensive search).  There is evidence that for vascular (blood vessel) effects, showing that Juul has the same adverse effects as an earlier generation e-cig or a Marlboro Red.  Because, like all e-cigarettes and cigarettes, Juul delivers an aerosol of ultrafine particles and chemicals to your lungs, the safest thing would be to stop.

Because it uses nicotine salts, Juul and similar e-cigs appear to be more addictive than older e-cigs (and maybe even conventional cigarettes).  I would seek help from your doctor or call your state quitline, which you can reach through 1-800-QUIT NOW.  Many also provide medications to help when appropriate.  Truth Initiative has a texting service targeted at Juul.

Health officials have said that people with existing conditions, including lung disease, are at increased risk, but have not, as far as I know, made any quantitative statements based on how severe the lung disease is.

What about heated tobacco products, like Philip Morris' IQOS?

The evidence that Phillip Morris submitted to the FDA shows that, in terms of effects on lung function, inflammation, and immune surpression, IQOS is not detectably different from a cigarette. The details are available here.

are the risks for COVID-19 associated with smoking or vaping cannabis?

The American Lung Association has a good summary of the evidence.  Cannabis smoke is very similar to tobacco smoke (other than a different psychoactive agent, THC vs nicotine).  And vaped cannabis delivers an aerosol of ultrafine particles and chemicals deep into the lungs too.

It would be sensible to stop using these cannabis products, too.

By the way, the federal government makes it almost impossible to study the cannabis products people are actually using.  If I went down the street to a local cannabis dispensary and bought some products off the shelf and brought them back to UCSF to study, even in a chemistry lab, the federal government could pull all federal funding to all 10 UC campuses.  This is a huge problem for scientists who are trying to get the answers to these reasonable questions that people are asking.

What about cannabis leaf vaporizers?

I haven't seen any direct evidence one way or the other in terms of pulmonary effects (although I didn't do an exhaustive search) of using a cannabis leaf vaporizer on pulmonary effects, but, like cigarettes and e-cigarettes, they develop an aerosol that you inhale.  There is evidence that for vascular (blood vessel) effects, vaporizers have similar adverse effects as combusted marijuana smoke.  All these different delivery modes -- smoking, vaping, vaporizers -- work by delivering an aerosol of ultrafine particles to your lungs to deliver the active ingredient (THC or nicotine).  Those particles are not a good thing for your lungs (or your vascular system).

My advice:  Don't put anything but air into your lungs.

What about using a cannibis bubbler to filter the flower?

It doesn't help.  Studies of tobacco hookah shows that the particles and gases are carried through the water in the bubbles.

 

Comments

Comment: 

There is probably a strong policy argument to be made for providing free NRT distribution through chain pharmacies and a boost in Quitline funding as part of the federal response to COVID-19. That would actually be a form of harm reduction we could all agree on.

Comment: 

I agree, but it is important that the NRT only be made available to those who are also part ofa formal smoking cessation program including counselling.  (State quitlines can provide the counselling.)

The tobacco companies figured out a long time ago that NRT used properly works, but used improperly -- without conselling -- actually keeps people smoking.  That's why they got into the NRT business a few years ago.  Sell it by the cash register like candy.

Comment: 

"Among Chinese patients diagnosed with COVID-19 associated pneumonia, the odds of disease progression (including to death) were 14 times higher among people with a history of smoking compared to those who did not smoke. This was the strongest risk factor among those examined".

14 times higher, what a statistic! This information needs to get out to the public. Few people know about this.

Comment: 

What are the implications for someone who quit smoking over seven years ago? Any idea?

Comment: 

The immune and inflammatory responses are generated by current exposure to the smoke/aerosol, so you are essentially a nonsmoker now.

Comment: 

I quit smoking three weeks ago? How will this affect me?

Comment: 

You are no longer bathing your lungs in toxic chemicals, so you are better off.  The cilia (liitle hairs that move foriegn particles out of your lungs so you can cough them out) are recovering.  CDC has a good summary of what happens after you quit, which is available here.

Comment: 

Thank you! That's quite the relief.

Comment: 

If I quit now will it help

Comment: 

Yes.  As I said in the blog post, this is new territory, but everything we know about how smoking and vaping affects lungs suggests that it wil.  It certainly won't hurt!

Comment: 

QUESTION ON CANNABIS CONSUMPTION: Hi Dr. Glantz, thank you for this article! I summarized your post in one of my COVID-19 daily updates (https://faithwashtub.livejournal.com/279.html) and I got a question regarding whether smoking or vaping cannabis would have a similar effect. Would you be able to describe what smoking or vaping cannabis would do in terms of raising your risk for severe illness from COVID-19, assuming it would? Thank you so much for your time and expertise, take care!

Comment: 

That is a a very good question.  As far as I know, no one has addressed it directly.  But we do know that cannabis smoke is very similar to tobacco smoke (other than a different psychoactive agent, THC vs nicotine).  And vaped cannabis delivers an aersolo of ultrafine particles and chemicals deep into the lungs. too.

It would be sensible to stop using these cannabis products, too.

By the way, the federal government makes it almost impossible to study the cannabis products people are actually using.  If I went down the street to a local cannabis dispensary and bought some products off the shelf and brought them back to UCSF to study, even in a chemistry lab, the federal government could pull all fderal funding to all 10 UC campuses.  This is a huge problem for scientists who are trying to get the answers to these reasonable questions that people are asking.

Comment: 

can contaminated cigarette smoke be linked to spreading covid19

Comment: 

I checked with some pulmonary specialists.  This is not something that has received much study.  The one study that looked at flu didn't find that smokers shed more virus.  No one seems to have studied vaping.

Comment: 

Any idea on the risk of juuling? I have been juuling a little under a year now and am trying to quit. I know a lot of long term effects of juuling (vaping) are still unknown, and the practical answer is to stop (consistently breathing in anything other than air is bad) but I was wondering if you know any further details? Is lung health status before contracting the virus the biggest determining factor in regards to mortality rate? If so, how can I check how heathy my lungs are? Should I be worried?

Comment: 

As far as I know, no one has yet studied Juul particularly in terms of effects on pulmonary immunity and inflammation (although I have not done a comprehensive search).  There is evidence that for vascular (blood vessel) effects, showing that Juul has the same adverse effects as an earlier generation e-cig or a Marlboro Red.  Because, like all e-cigarettes and cigarettes, Juul delivers an aerosol of ultrafine particles and chemicals to your lungs, the safest thing would be to stop.

Because it uses nicotine salts, Juul and similar e-cigs appear to be more addicitive than older e-cigs (and maybe even conventional cigarettes).  I would seek help from your doctor or call your state quitline, which you can reach through 1-800-QUIT NOW.  Many also provide medications to help when appropriate.  Truth Initiative has a texting service targeted at Juul.

Health officials have said that people with existing conditions, including lung disease, are at increased risk, but have not, as far as I know, made any quantitative statements based on how severe the lung disease is.

Comment: 

Dear Dr. Glantz, I quit smoking 2 months ago and am currently using 2mg nicotine lozenges. Should I now also stop those because of your finding on Cotinine/Nicotine?

Really appreciate that you are answering these comments as reliable info is hard to find

Comment: 

The effects of concern are due to the inhaled aerosol, not nicotine in your blood (which is what the NRT does).  You should eventually wean yourself off the NRT (because it has other effects), but I would stay on the NRT until you are sure that you are past smoking.

 

Comment: 

I am a current smoker and terrified of getting this virus. If I quit smoking today how long will it take for cotinine/nicotine to get out of my body? I’m shocked that the media isn’t publicizing this heightened risk about smoking and the Coronavirus. I also have asthma too so I know that is dangerous and that smoking is harmful but didn’t realize that it greatly increases your risks due to the cotinine in cigarettes. The public needs to know about this ASAP because the people who I know that smoke or vape etc had no idea about the deadly links between the two. I’ve been trying to quit for a while but this is it, I’m done.

Comment: 

Congradulations on quitting.

As I said in response to another comment, it is the inhaled aerosol not the nicotine in your blood that is causing most of the problems.  The effects of smoking start resolving as soon as you stop.  The CDC link I posted earlier includes information of how quickly different things start changing.

Comment: 

“ People who have any cotinine (a metabolite of nicotine) in their bodies – even at the low levels associated with secondhand smoke”

“Bodies” is vague. I assume should read “respiratory system” since NRT gum would not increase chances of severe infection, correct?

Comment: 

I recently quit juuling and now am scared since I am using Nicotine replacement therapy, patches or gum. Is the nicotine in them just as dangerous as the juul?

Comment: 

You are much better off quitting.  You are not inhaling the untrafine aerosol that Juul and other e-cigs -- and cigarettes -- deliver to your lungs.

Once you are sure you are de-addicted, you should get off the NRT, but stay on it as long as you need to avoid Juul.  Counselling helps.  State quitlines are available for free.

Comment: 

Thanks for the clarification.

If I got this right, it's all about aerosol and/or chemicals which result from combustion. You wrote earlier that "vaped cannabis delivers an aerosole of ultrafine particles and chemicals deep into the lungs, too". Is that also valid for vaporizers which work with heat only (no liquids, no combustion)?

Thank you for your work.

Comment: 

I haven't seen any direct evidence one way or the other in terms of pulmonary effects (although I didn't do an exhaustive search).  There is evidence that for vascular (blood vessel) effects, vaporizers have similar adverse effects as combusted marijuana smoke.  All these different delivery modes -- smoking, vaping, vaporizers -- all work by delivering an aerosol of ultrafine particles to your lungs to deliver the active ingredient (THC or nicotine).  Those particles are not a good thing for your lungs (or your vascular system).

My advice:  Don't put anything but air into your lungs.

Comment: 

Cleveland Clinic weighs in: https://health.clevelandclinic.org/teens-vaping-and-coronavirus-is-there-a-connection/

Comment: 

What about using a cannibus bubbler to filter the flower?

Comment: 

It doesn't matter.  Studies of tobacco hookah shows that the particles and gases are carried through the water in the bubbles.

Comment: 

I’m 75 years old and have smoked sense I was 15, had heart attack 14 years ago, one stent, went from 3 packs a day to a pack every 3 days. But I having been using 4 milligram nicotine lozenges sense the heart attack. I am additional to them. If the French study o nicotine and the corns virus pans out would the nicotine from the lozenges have the same effect as nicotine gum?

Comment: 

All forms of NRT work by increasing the level of nicotine in your blood, so the effects would be the same.

I will be surprised if the French study works, since the ACE2 receptor faces the air side of the lungs, not the blood side, which the NRT affects.

Comment: 

Multiple studies have shown that smokers have been hugely underrepresented in terms of Covid19 hospitalisations (even Norway removed smoking as a CV risk factor).
How do you explain this?

Comment: 

It is true that the studies on smoking and COVID-19 report lower levels of smoking among COVID-19 patients than in the general population.  This under-reporting is likely due to the fact that these patients are often very sick, sometimes not concious or on ventilators, which makes it difficult if not impossible to assess smoking status.  So, it is not reliable to draw any conclusions about the low reported smoking rates.

Even accounting for the under-reporting of smoking, patients with COVID-19 who smoke do worse than patients who do not smoke.  Our meta-analysis of 19 studies on this question is available here.  It addresses the underreporting issue in the Discussion section, noting that the result of the underreporting of smoking makes it likely that the current studies are underestimating the risk of smoking.

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