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Front Public Health
. 2026 Apr 16:14:1725232.
doi: 10.3389/fpubh.2026.1725232. eCollection 2026.
Influenza-like illness in cigarette smokers and electronic-cigarette users: a secondary analysis from the PAIVED study
Rachael D C Jones 1 , Kat Schmidt 2 3 , Christina Schofield 4 , Anuradha Ganesan 2 3 5 , Wesley Campbell 5 , David Hrncir 6 7 8 , Tahaniyat Lalani 2 3 9 , Katrin Mende 2 3 10 , Ana E Markelz 10 , Catherine M Berjohn 2 11 12 , Laurie Housel 8 13 , Drake H Tilley 2 14 , Adam Saperstein 15 , Alan Williams 15 , Bruce McClenathan 8 13 , Limone Collins 8 , Christina Spooner 8 , Srihari Seshadri 8 , Ryan C Maves 2 12 16 , Robert J O'Connell 2 , Simon Pollett 2 3 , Mark P Simons 2 3 , John H Powers 3rd 17 , Christian L Coles 2 3 , Rhonda E Colombo 2 3 4 11 , Timothy H Burgess 2 , Stephanie A Richard 2 3
Affiliations
Background: The Pragmatic Assessment of Influenza Vaccine Effectiveness in the Department of Defense (PAIVED) study was a clinical trial of three influenza vaccines in military beneficiaries enrolled at 10 military treatment facilities over four influenza seasons (2018/19-2021/22). This secondary analysis aimed to assess the relationship between cigarette smoking and e-cigarette use and influenza-like illness (ILI) incidence and severity.
Methods: Demographic information, including cigarette smoking and e-cigarette use, was collected at enrollment. ILIs were identified during the influenza season of enrollment using weekly surveys. ILI symptoms were reported using the inFLUenza Patient-Reported Outcome (FLU-PRO) instrument. The relationship between smoking status and risk of reporting an ILI was estimated using Poisson regression; ILI severity was compared by cigarette smoking and e-cigarette use using multivariable linear regression.
Results: Among 8,708 participants with cigarette smoking status, 4.3% were current smokers and 11.9% were former smokers. Current cigarette smokers reported higher respiratory domain scores (0.24 (95% CI: 0.07, 0.41)) than non-smokers; former cigarette smokers were at higher risk of reporting an ILI than non-smokers [rate ratio 1.11 (95% CI: 1.02, 1.20)] and reported ILI episodes that were on average 1.23 days longer in duration (95% CI: 0.29, 2.17). Among 8,119 participants with e-cigarette use status, 3.9% were current users and 2.6% were former users. Current e-cigarette users reported more than one additional day with limited activity (1.14 days, 95% CI: 0.10, 2.18) and 0.78 additional days with fever (95% CI, 0.20, 1.35); former e-cigarette users were at higher risk of reporting an ILI than nonusers [rate ratio 1.20 (95% CI, 1.04, 1.38)] and reported higher respiratory domain scores than non-users (0.27 (95% CI 0.08, 0.46)).
Conclusion: We observed slightly higher ILI risk in former cigarette smokers and e-cigarette users, longer symptom duration in former cigarette smokers, and higher respiratory symptom scores in current cigarette smokers and former e-cigarette users compared to non-smokers/users. Findings in this secondary analysis are exploratory and hypothesis-generating; additional studies are needed to confirm the relationships reported here.
Keywords: cigarettes; electronic-cigarettes; influenza-like illness; respiratory infections; smoking.
. 2026 Apr 16:14:1725232.
doi: 10.3389/fpubh.2026.1725232. eCollection 2026.
Influenza-like illness in cigarette smokers and electronic-cigarette users: a secondary analysis from the PAIVED study
Rachael D C Jones 1 , Kat Schmidt 2 3 , Christina Schofield 4 , Anuradha Ganesan 2 3 5 , Wesley Campbell 5 , David Hrncir 6 7 8 , Tahaniyat Lalani 2 3 9 , Katrin Mende 2 3 10 , Ana E Markelz 10 , Catherine M Berjohn 2 11 12 , Laurie Housel 8 13 , Drake H Tilley 2 14 , Adam Saperstein 15 , Alan Williams 15 , Bruce McClenathan 8 13 , Limone Collins 8 , Christina Spooner 8 , Srihari Seshadri 8 , Ryan C Maves 2 12 16 , Robert J O'Connell 2 , Simon Pollett 2 3 , Mark P Simons 2 3 , John H Powers 3rd 17 , Christian L Coles 2 3 , Rhonda E Colombo 2 3 4 11 , Timothy H Burgess 2 , Stephanie A Richard 2 3
Affiliations
- PMID: 42077984
- PMCID: PMC13130645
- DOI: 10.3389/fpubh.2026.1725232
Background: The Pragmatic Assessment of Influenza Vaccine Effectiveness in the Department of Defense (PAIVED) study was a clinical trial of three influenza vaccines in military beneficiaries enrolled at 10 military treatment facilities over four influenza seasons (2018/19-2021/22). This secondary analysis aimed to assess the relationship between cigarette smoking and e-cigarette use and influenza-like illness (ILI) incidence and severity.
Methods: Demographic information, including cigarette smoking and e-cigarette use, was collected at enrollment. ILIs were identified during the influenza season of enrollment using weekly surveys. ILI symptoms were reported using the inFLUenza Patient-Reported Outcome (FLU-PRO) instrument. The relationship between smoking status and risk of reporting an ILI was estimated using Poisson regression; ILI severity was compared by cigarette smoking and e-cigarette use using multivariable linear regression.
Results: Among 8,708 participants with cigarette smoking status, 4.3% were current smokers and 11.9% were former smokers. Current cigarette smokers reported higher respiratory domain scores (0.24 (95% CI: 0.07, 0.41)) than non-smokers; former cigarette smokers were at higher risk of reporting an ILI than non-smokers [rate ratio 1.11 (95% CI: 1.02, 1.20)] and reported ILI episodes that were on average 1.23 days longer in duration (95% CI: 0.29, 2.17). Among 8,119 participants with e-cigarette use status, 3.9% were current users and 2.6% were former users. Current e-cigarette users reported more than one additional day with limited activity (1.14 days, 95% CI: 0.10, 2.18) and 0.78 additional days with fever (95% CI, 0.20, 1.35); former e-cigarette users were at higher risk of reporting an ILI than nonusers [rate ratio 1.20 (95% CI, 1.04, 1.38)] and reported higher respiratory domain scores than non-users (0.27 (95% CI 0.08, 0.46)).
Conclusion: We observed slightly higher ILI risk in former cigarette smokers and e-cigarette users, longer symptom duration in former cigarette smokers, and higher respiratory symptom scores in current cigarette smokers and former e-cigarette users compared to non-smokers/users. Findings in this secondary analysis are exploratory and hypothesis-generating; additional studies are needed to confirm the relationships reported here.
Keywords: cigarettes; electronic-cigarettes; influenza-like illness; respiratory infections; smoking.