A new study published in the British Journal of Cancer is challenging the way lung-cancer risk is discussed among people who do not smoke conventional cigarettes. Researchers led by S. Vaja, J.L. Dickson and C. Horst examined the effects of cigar, cigarillo and pipe smoking, focusing on two questions with immediate public-health consequences: how these products influence the likelihood of developing lung cancer and whether their users are being identified as eligible for screening.

Lung-cancer prevention strategies have traditionally been built around cigarette consumption, especially the number of cigarette packs smoked per year. This measure, known as pack-years, combines smoking intensity and duration. One pack-year generally represents smoking 20 cigarettes a day for one year. Because cigars, cigarillos and pipes are used differently from cigarettes, their tobacco exposure is harder to convert into the same standardized measurement. That difference can leave regular users outside the systems designed to identify people at high risk.

The study addresses a persistent misconception: that alternative combustible tobacco products are inherently safer because they are not smoked in the same way as cigarettes. Cigar and pipe users may inhale less deeply or less frequently, but the smoke still contains carcinogenic compounds produced by burning tobacco. These include polycyclic aromatic hydrocarbons, tobacco-specific nitrosamines, volatile organic compounds and fine particulate matter. The precise dose entering the lungs can vary substantially, yet repeated exposure can still damage airway cells and contribute to mutations associated with cancer development.

Cigarillos occupy a particularly complicated position because they range from small, cigarette-like products to larger cigars that may be smoked over a longer period. Their nicotine content and smoke volume can also differ widely. Some users inhale cigarillo smoke deeply, while others do not. Pipes introduce another set of variables, including the duration of a smoking session, the amount of tobacco burned and the frequency with which the pipe is used. These differences make simple comparisons difficult, but they do not eliminate the biological hazards of combustion.

According to the research, the central concern is not only whether cigar, cigarillo and pipe smoking increases lung-cancer risk, but also whether current screening rules recognize that risk. Lung-cancer screening commonly relies on age and a history of cigarette smoking measured in pack-years. People who have smoked other combustible tobacco products may therefore be classified as having insufficient exposure, even when their cumulative tobacco use has been substantial. If risk is underestimated at the eligibility stage, some people could miss the opportunity to detect a tumour before symptoms appear.

Screening works by identifying disease at an earlier and more treatable stage, often using low-dose computed tomography, or LDCT. Unlike a conventional CT scan, LDCT uses a lower radiation dose to create detailed images of the lungs. Its effectiveness depends on selecting people whose probability of developing lung cancer is high enough to justify the benefits and potential harms of testing. Those harms include false-positive findings, unnecessary follow-up procedures, anxiety and cumulative radiation exposure. The challenge is to expand access without encouraging indiscriminate scanning.

The researchers’ analysis highlights why tobacco history needs to be recorded in greater detail. A questionnaire that asks only whether someone smokes cigarettes can overlook the frequency, duration and type of cigar, cigarillo or pipe use. It may also fail to capture former users whose exposure occurred years earlier. More comprehensive risk models could incorporate the number of products used, smoking intensity, years since quitting, inhalation patterns and additional factors such as age, occupational exposure, air pollution and family history.

The findings also carry a message for people who use these products socially or intermittently. Risk is not determined solely by whether smoking occurs every day. The biological impact depends on cumulative exposure, the composition of the product and how smoke is inhaled. Occasional use may carry less risk than heavy, long-term use, but “less” does not mean “none.” Combustible tobacco remains fundamentally different from non-combustible nicotine products because burning creates the toxic mixture responsible for much of the damage to the respiratory system.

The study does not suggest that every cigar or pipe smoker should automatically undergo a CT scan. Instead, it points to a gap between real-world tobacco exposure and the simplified categories used in many screening policies. The authors’ work could encourage clinicians and policymakers to assess alternative tobacco use more systematically and to investigate whether existing eligibility thresholds should be adapted. Any change would require careful validation, because screening recommendations must balance earlier diagnosis against the risks of testing people who are unlikely to benefit.

The broader lesson is that lung-cancer risk cannot be reduced to a single cigarette-based number. As smoking patterns evolve and tobacco products diversify, prevention programmes must keep pace with the ways people actually consume tobacco. The study by Vaja and colleagues adds evidence that cigar, cigarillo and pipe smoking deserve a more visible place in lung-health research and clinical risk assessment. For now, the clearest preventive message remains unchanged: avoiding all combustible tobacco products offers the strongest protection, while anyone with a history of substantial use should discuss their individual risk with a healthcare professional.

Subject of Research: The effects of cigar, cigarillo and pipe smoking on lung-cancer risk and eligibility for lung-cancer screening.

Article Title: The effect of cigar, cigarillo and pipe smoking on lung cancer risk and screening eligibility.

Article References: Vaja, S., Dickson, J.L., Horst, C. et al. “The effect of cigar, cigarillo and pipe smoking on lung cancer risk and screening eligibility.” British Journal of Cancer (2026). https://doi.org/10.1038/s41416-026-03578-9

Image Credits: AI Generated

DOI: 10.1038/s41416-026-03578-9

Keywords: lung cancer, cigar smoking, cigarillo smoking, pipe smoking, tobacco exposure, cancer screening, low-dose CT, smoking-related cancer, public health, epidemiology

The apparent benefits of updated COVID-19 vaccines in older adults may be influenced by more than the vaccines themselves, according to a study examining the “healthy vaccinee effect,” a form of bias that can complicate observational research. Published in Nature Communications, the work by Lyth, Spreco, Hinkula and colleagues focuses on how differences between people who receive vaccination and those who do not can alter estimates of vaccine effectiveness, particularly in elderly populations whose health status can change rapidly.

Updated COVID-19 vaccines are designed to improve protection against circulating SARS-CoV-2 variants, especially protection against severe disease, hospitalization and death. Because randomized clinical trials are not usually repeated for every reformulated vaccine and every emerging variant, researchers frequently rely on real-world health data. These studies compare outcomes among vaccinated and unvaccinated people, but the two groups may differ in important ways before vaccination occurs. Such differences can produce an apparent vaccine benefit—or obscure a real one—even when the analysis carefully accounts for age and medical conditions.

The healthy vaccinee effect arises when people who are vaccinated are temporarily healthier, more active or better connected to healthcare services than those who remain unvaccinated. Individuals may postpone vaccination during an acute illness, after hospitalization or when they are approaching the end of life. At the same time, people who attend vaccination appointments may be more likely to receive preventive care, follow medical advice and seek treatment early. These characteristics are not necessarily caused by vaccination, but they can lower the vaccinated group’s risk of death or hospitalization during the period used for analysis.

This issue is particularly important in older populations. Elderly people often have multiple chronic conditions, fluctuating functional status and frequent contact with hospitals or long-term care facilities. A person may be eligible for a vaccine campaign but unable to receive the dose because of an acute health problem. If that person later dies or is hospitalized, conventional analyses may attribute the worse outcome to the absence of vaccination, even though the underlying illness was already present. Conversely, if researchers compare groups immediately after vaccination without accounting for this selection process, the vaccine may appear more protective than it truly is.

The study evaluates how this bias affects assessments of updated COVID-19 vaccines in elderly populations. Its central scientific contribution is to treat vaccination not simply as an exposure, but as an event embedded in a changing health trajectory. The health of older adults is not static: frailty, infection, recent hospitalization and access to care can all influence whether and when vaccination occurs. By examining these time-dependent factors, the researchers draw attention to the difference between a vaccine’s biological effect and the characteristics of the people who are able to receive it at a particular moment.

In epidemiological terms, the healthy vaccinee effect is a form of confounding and selection bias. Confounding occurs when another factor is associated with both vaccination and the outcome being measured. Selection bias occurs when inclusion in the vaccinated or comparison group depends on health-related circumstances. Timing can intensify both problems. If follow-up begins on the day of vaccination for one group but at an arbitrary date for another, the groups may not have equivalent baseline risks. Researchers therefore need to define an appropriate index date, align observation periods and account for recent illness, healthcare use and changes in eligibility.

The challenge is not merely statistical. A vaccine can provide strong protection against severe COVID-19 while producing a smaller or more variable effect against infection, depending on the variant, time since vaccination, prior immunity and the outcome being studied. If an observational analysis reports a lower mortality rate among vaccinated people, that result may reflect a combination of direct vaccine protection and the healthier profile of vaccine recipients. Separating these components requires careful design, including adjustment for measured risk factors and, where possible, comparison strategies that mimic a randomized trial.

The findings have practical implications for interpreting public-health evidence. Estimates of updated vaccine effectiveness should not be read in isolation from the population being studied, the timing of vaccination and the definition of the unvaccinated comparison group. Researchers may need to conduct sensitivity analyses, use negative-control outcomes, examine short intervals after vaccination and account for healthcare-seeking behavior. Analyses that compare people with similar recent health histories, or that use methods designed for time-varying confounding, can help determine whether an observed association is likely to represent a genuine vaccine effect.

The study does not undermine the value of COVID-19 vaccination for older adults; rather, it highlights the methodological care required to measure that value accurately. For clinicians, policymakers and the public, the message is that real-world vaccine evidence is strongest when biological protection is evaluated alongside the circumstances that determine who gets vaccinated and when. As SARS-CoV-2 continues to evolve and vaccine formulations are periodically updated, understanding the healthy vaccinee effect will remain essential for distinguishing the protection delivered by immunization from the protection that appears because healthier people are more likely to receive it.

Subject of Research: Healthy vaccinee effect and the evaluation of updated COVID-19 vaccines in elderly populations.

Article Title: Healthy vaccinee effect in the evaluation of updated COVID-19 vaccines in elderly populations.

Article References:

Lyth, J., Spreco, A., Hinkula, J. et al. Healthy vaccinee effect in the evaluation of updated COVID-19 vaccines in elderly populations. Nat Commun 17, 8014 (2026). https://doi.org/10.1038/s41467-026-76312-x

Image Credits: AI Generated

DOI: https://doi.org/10.1038/s41467-026-76312-x

Keywords: COVID-19 vaccines, updated vaccines, SARS-CoV-2, elderly populations, healthy vaccinee effect, vaccine effectiveness, epidemiology, observational studies, confounding, public health.

Ethan Siegel’s approach to public discussion of science is common enough: the exalted scientist reaches down to the ignorant masses.

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