tetano
Editor, Senior Moderator
Open Forum Infect Dis
. 2026 Jan 12;13(1)
faf728.
doi: 10.1093/ofid/ofaf728. eCollection 2026 Jan.
Healthcare Workers Have More Frequent and Less Severe Influenza-Like Illness Than Non-healthcare Workers: Findings From the PAIVED Study
Ryan Liberg[SUP] 1 [/SUP], Kat Schmidt[SUP] 2 3 [/SUP], Christina Schofield[SUP] 4 [/SUP], Anuradha Ganesan[SUP] 2 3 5 [/SUP], Wesley Campbell[SUP] 5 [/SUP], David Hrncir[SUP] 6 7 8 [/SUP], Tahaniyat Lalani[SUP] 2 3 9 [/SUP], Tyler Warkentien[SUP] 9 [/SUP], Katrin Mende[SUP] 1 2 3 [/SUP], Ana E Markelz[SUP] 1 [/SUP], Catherine M Berjohn[SUP] 2 10 11 [/SUP], Laurie Housel[SUP] 8 12 [/SUP], Jitendrakumar R Modi[SUP] 13 [/SUP], Adam Saperstein[SUP] 14 [/SUP], Alan Williams[SUP] 14 [/SUP], Bruce McClenathan[SUP] 8 12 [/SUP], Christina Spooner[SUP] 8 [/SUP], Srihari Seshadri[SUP] 8 [/SUP], Ryan C Maves[SUP] 2 11 15 [/SUP], John H Powers 3rd[SUP] 16 [/SUP], Robert J O'Connell[SUP] 2 [/SUP], Mark P Simons[SUP] 2 3 [/SUP], Simon D Pollett[SUP] 2 3 [/SUP], Christian L Coles[SUP] 2 3 [/SUP], Rhonda E Colombo[SUP] 2 3 4 10 [/SUP], Timothy Burgess[SUP] 2 [/SUP], Stephanie A Richard[SUP] 2 3 [/SUP]
Affiliations
Background: The Pragmatic Assessment of Influenza Vaccine Effectiveness in the Department of Defense (PAIVED) study is a multicenter trial assessing influenza vaccine effectiveness with annual enrollment over 4 consecutive influenza seasons (2018/2019-2021/2022). Data from PAIVED provides an opportunity to evaluate influenza-like illness (ILI) in healthcare workers (HCWs) compared to non-HCWs.
Methods: Participants in the PAIVED study were recruited from September to January in each influenza season and received egg-based, cell-based, or recombinant influenza vaccine. If a participant reported an ILI, they submitted a nasal swab for pathogen detection and a symptom diary for 7 days. For this analysis, vaccine groups were pooled and multivariable regression models were performed.
Results: Among the 13 959 participants included in this analysis, 35% were HCWs. Healthcare workers were more likely to be female, white, and 25-44 years of age. In addition, HCWs were more likely to report ILIs than non-HCWs (24.1% vs 17.4%, P < .01), and this difference persisted in our multivariable model (RR 1.16 [95% CI 1.08, 1.24]). No statistically significant differences were observed between HCWs and non-HCWs in specific pathogen detection. In terms of ILI severity, HCWs reported 0.28 more days of missed work (95% CI 0.01, 0.55), 0.36 fewer days with fever (-0.60, -0.13), and, in general, reported less severe ILI symptoms in the FLU-PRO diaries.
Conclusions: Healthcare workers enrolled in PAIVED reported more ILIs during the study period than non-HCWs, despite all participants receiving influenza vaccination. Further work is needed to reduce the risk of ILIs in HCWs.
Clinical trials registration: A Pragmatic Assessment of Influenza Vaccine Effectiveness in the DoD (PAIVED): NCT03734237, Study Details | A Pragmatic Assessment of Influenza Vaccine Effectiveness in the DoD | ClinicalTrials.gov.
Keywords: healthcare worker; influenza; respiratory infection; vaccine.
. 2026 Jan 12;13(1)
faf728.doi: 10.1093/ofid/ofaf728. eCollection 2026 Jan.
Healthcare Workers Have More Frequent and Less Severe Influenza-Like Illness Than Non-healthcare Workers: Findings From the PAIVED Study
Ryan Liberg[SUP] 1 [/SUP], Kat Schmidt[SUP] 2 3 [/SUP], Christina Schofield[SUP] 4 [/SUP], Anuradha Ganesan[SUP] 2 3 5 [/SUP], Wesley Campbell[SUP] 5 [/SUP], David Hrncir[SUP] 6 7 8 [/SUP], Tahaniyat Lalani[SUP] 2 3 9 [/SUP], Tyler Warkentien[SUP] 9 [/SUP], Katrin Mende[SUP] 1 2 3 [/SUP], Ana E Markelz[SUP] 1 [/SUP], Catherine M Berjohn[SUP] 2 10 11 [/SUP], Laurie Housel[SUP] 8 12 [/SUP], Jitendrakumar R Modi[SUP] 13 [/SUP], Adam Saperstein[SUP] 14 [/SUP], Alan Williams[SUP] 14 [/SUP], Bruce McClenathan[SUP] 8 12 [/SUP], Christina Spooner[SUP] 8 [/SUP], Srihari Seshadri[SUP] 8 [/SUP], Ryan C Maves[SUP] 2 11 15 [/SUP], John H Powers 3rd[SUP] 16 [/SUP], Robert J O'Connell[SUP] 2 [/SUP], Mark P Simons[SUP] 2 3 [/SUP], Simon D Pollett[SUP] 2 3 [/SUP], Christian L Coles[SUP] 2 3 [/SUP], Rhonda E Colombo[SUP] 2 3 4 10 [/SUP], Timothy Burgess[SUP] 2 [/SUP], Stephanie A Richard[SUP] 2 3 [/SUP]
Affiliations
- PMID: 41531506
- PMCID: PMC12794008
- DOI: 10.1093/ofid/ofaf728
Background: The Pragmatic Assessment of Influenza Vaccine Effectiveness in the Department of Defense (PAIVED) study is a multicenter trial assessing influenza vaccine effectiveness with annual enrollment over 4 consecutive influenza seasons (2018/2019-2021/2022). Data from PAIVED provides an opportunity to evaluate influenza-like illness (ILI) in healthcare workers (HCWs) compared to non-HCWs.
Methods: Participants in the PAIVED study were recruited from September to January in each influenza season and received egg-based, cell-based, or recombinant influenza vaccine. If a participant reported an ILI, they submitted a nasal swab for pathogen detection and a symptom diary for 7 days. For this analysis, vaccine groups were pooled and multivariable regression models were performed.
Results: Among the 13 959 participants included in this analysis, 35% were HCWs. Healthcare workers were more likely to be female, white, and 25-44 years of age. In addition, HCWs were more likely to report ILIs than non-HCWs (24.1% vs 17.4%, P < .01), and this difference persisted in our multivariable model (RR 1.16 [95% CI 1.08, 1.24]). No statistically significant differences were observed between HCWs and non-HCWs in specific pathogen detection. In terms of ILI severity, HCWs reported 0.28 more days of missed work (95% CI 0.01, 0.55), 0.36 fewer days with fever (-0.60, -0.13), and, in general, reported less severe ILI symptoms in the FLU-PRO diaries.
Conclusions: Healthcare workers enrolled in PAIVED reported more ILIs during the study period than non-HCWs, despite all participants receiving influenza vaccination. Further work is needed to reduce the risk of ILIs in HCWs.
Clinical trials registration: A Pragmatic Assessment of Influenza Vaccine Effectiveness in the DoD (PAIVED): NCT03734237, Study Details | A Pragmatic Assessment of Influenza Vaccine Effectiveness in the DoD | ClinicalTrials.gov.
Keywords: healthcare worker; influenza; respiratory infection; vaccine.