CDC’s new mask guidance and why FDA CTP should not assume e-cigs help smokers quit in the real world

On May 13, 2021 the CDC lifted most restrictions on the use of masks for people fully vaccinated against COVID-19 (two weeks after the second shot for Pfizer or Moderna and 1 week after J&J).

While some people thought this was a political decision, CDC Director Walensky explained in detail that real world experience showed that all three vaccines were as effective in preventing infection and serious health effects in the real world as the efficacy as in the controlled clinical trials conducted before the vaccines that formed the basis for FDA granting emergency use authorization for human use.

This is often not the case. It is not unusual for medicines that show efficacy in clinical trials produce disappointing effectiveness in real world use. There are many reasons that effectiveness is often lower than efficacy, including the fact that in clinical trials use of the treatment is tightly monitored and supervised whereas in the real world patients are rarely monitored and supervised so closely. Another reason is that the clinical trial involves testing the treatment on a well-specified group of people whereas a much broader group of people use the drug in the population. In addition, in the real world is people often do not use the treatment the same way that they were tested in the clinical trials, such as not following the dosing or frequency of use that was tested in the clinical trials.

The fact that the government and health authorities have worked so hard to see that the vaccines are used among the same kinds of people that were tested in the clinical trials and took care that the dosing and timing was the same as in the trials likely explains why the COVID vaccines’ effectiveness is so close to their efficacy.

What does this have to do with e-cigs and smoking cessation?

The clinical trials show that, under clinical supervision, e-cigs have efficacy as smoking cessation aids. At the same time, the population studies show that e-cigs are not effective for smoking cessation.

As we have pointed out in detail, it is the effectiveness standard that the FDA Center for Tobacco Products (CTP) should use when assessing whether authorizing the sale of e-cigarettes as consumer products in “appropriate for the protection of public health,” the standard in the law.

The fact that e-cigarettes are efficacious is the clinical trials suggests that they might be appropriate as cessation aids when used under medical supervision as a cessation treatment if the risks/benefit profile is favorable. This is precisely the question that the FDA Center for Drug Evaluation and Research (CEDR) would address if any e-cig company applied for approval of e-cigarettes as a smoking cessation therapy. (So far, as far as I know, no e-cig company has applied for such an approval.)

The lack of effectiveness in the population means that if the FDA CEDR were to approve e-cigarettes as a clinical cessation aid, it should require that they be used under prescription. Why? To increase the chances that they were used under the same conditions as the clinical trials (as with COVID vaccines). In particular, the lack of effectiveness of e-cigarettes as unsupervised consumer products means that they should not be approved for over-the-counter (unsupervised) use.

Another important distinction between CTP and CEDR is that only CDER can put restrictions on who should use them and how they should be used. CTP can only give a yes or no to authorizing the sale of e-cigarettes as consumer products.

When considering e-cigarettes and smoking cessation both CTP and CDER have the benefit of the years that e-cigs have been available to observe actual effectiveness. Most of the time, when considering applications for new therapies FDA only has the efficacy data from clinical trials. Now, both have the benefit of the real world effectiveness.

The CDC’s care in making its mask decision is a great example of the importance of considering this distinction.

Published by Stanton Glantz

Stanton Glantz is a retired Professor of Medicine who served on the University of California San Francisco faculty for 45 years. He conducts research on tobacco and cannabis control and cardiovascular disease/

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