Influence of Preseason Antibodies Against Influenza Virus on Risk of Influenza Infection Among Healthcare Personnel

• Published in: The Journal of infectious diseases Vol. 225; no. 5; pp. 891 - 902
• Main Authors: Gorse, Geoffrey J, Rattigan, Susan M, Kirpich, Alexander, Simberkoff, Michael S, Bessesen, Mary T, Gibert, Cynthia, Nyquist, Ann-Christine, Price, Connie Savor, Gaydos, Charlotte A, Radonovich, Lewis J, Perl, Trish M, Rodriguez-Barradas, Maria C, Cummings, Derek A T
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 02-03-2022
• Subjects: Antibodies; Antibodies, Viral; Delivery of Health Care; Health care; Hemagglutination inhibition; Hemagglutination Inhibition Tests; Humans; Infections; Influenza; Influenza A; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H3N2 Subtype; Influenza Vaccines; Influenza, Human - epidemiology; Influenza, Human - prevention & control; Occupational exposure; Orthomyxoviridae Infections; Personnel; Polymerase chain reaction; Respirators; Vaccination; Viruses; healthcare personnel; influenza virus; correlates of protection; hemagglutination inhibition antibodies
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1093/infdis/jiab468

Abstract
Background
The association of hemagglutination inhibition (HAI) antibodies with protection from influenza among healthcare personnel (HCP) with occupational exposure to influenza viruses has not been well-described.
Methods
The Respiratory Protection Effectiveness Clinical Trial was a cluster-randomized, multisite study that compared medical masks to N95 respirators in preventing viral respiratory infections among HCP in outpatient healthcare settings for 5180 participant-seasons. Serum HAI antibody titers before each influenza season and influenza virus infection confirmed by polymerase chain reaction were studied over 4 study years.
Results
In univariate models, the risk of influenza A(H3N2) and B virus infections was associated with HAI titers to each virus, study year, and site. HAI titers were strongly associated with vaccination. Within multivariate models, each log base 2 increase in titer was associated with 15%, 26% and 33%–35% reductions in the hazard of influenza A(H3N2), A(H1N1), and B infections, respectively. Best models included preseason antibody titers and study year, but not other variables.
Conclusions
HAI titers were associated with protection from influenza among HCP with routine exposure to patients with respiratory illness and influenza season contributed to risk. HCP can be reassured about receiving influenza vaccination to stimulate immunity.
Hemagglutination inhibition antibody titers against influenza A and B viruses were associated with protection from influenza infection among healthcare personnel working in outpatient settings and with vaccination status, reinforcing the importance of vaccination to stimulate immunity.