The Household Influenza Vaccine Effectiveness Study Lack of Antibody Response and Protection Following Receipt of 2014–2015 Influenza Vaccine

• Published in: Clinical infectious diseases Vol. 65; no. 10; pp. 1644 - 1651
• Main Authors: Petrie, Joshua G., Malosh, Ryan E., Cheng, Caroline K., Ohmit, Suzanne E., Martin, Emily T., Johnson, Emileigh, Truscon, Rachel, Eichelberger, Maryna C., Gubareva, Larisa V., Fry, Alicia M., Monto, Arnold S.
• Format: Journal Article
• Language: English
• Published: United States Oxford University Press 15.11.2017
• Subjects: Adolescent; Adult; Adults; and Commentaries; Antibodies, Viral - blood; Antibody response; Antigens; ARTICLES AND COMMENTARIES; Child; Children; Cohort Studies; Confidence intervals; Effectiveness; Exo-a-sialidase; Female; Health risks; Hemagglutination; Households; Humans; Immunoglobulins; Infections; Influenza; Influenza A; Influenza A Virus, H3N2 Subtype - immunology; Influenza B; Influenza B virus - immunology; Influenza Vaccines - immunology; Influenza, Human - epidemiology; Influenza, Human - immunology; Inhibition; Male; Middle Aged; Vaccine efficacy; Vaccines; Viruses; Young Adult; influenza; vaccine effectiveness; serologic susceptibility; vaccine response; household cohort study
• ISSN: 1058-4838; 1537-6591; 1537-6591
• DOI: 10.1093/cid/cix608

Antigenically drifted A(H3N2) viruses circulated extensively during the 2014-2015 influenza season. Vaccine effectiveness (VE) was low and not significant among outpatients but in a hospitalized population was 43%. At least one study paradoxically observed increased A(H3N2) infection among those vaccinated 3 consecutive years. We followed a cohort of 1341 individuals from 340 households. VE against laboratory-confirmed influenza was estimated. Hemagglutination-inhibition and neuraminidase-inhibition antibody titers were determined in subjects ≥13 years. Influenza A(H3N2) was identified in 166 (12%) individuals and B(Yamagata) in 34 (2%). VE against A(H3N2) was -3% (95% confidence interval [CI]: -55%, 32%) and similarly ineffective between age groups; increased risk of infection was not observed among those vaccinated in 2 or 3 previous years. VE against influenza B(Yamagata) was 57% (95% CI: -3%, 82%) but only significantly protective in children <9 years (87% [95% CI: 43%, 97%]). Less than 20% of older children and adults had ≥4-fold antibody titer rise against influenza A(H3N2) and B antigens following vaccination; responses were surprisingly similar for antigens included in the vaccine and those similar to circulating viruses. Antibody against A/Hong Kong/4801/14, similar to circulating 2014-2015 A(H3N2) viruses and included in the 2016-2017 vaccine, did not significantly predict protection. Absence of VE against A(H3N2) was consistent with circulation of antigenically drifted viruses; however, generally limited antibody response following vaccination is concerning even in the context of antigenic mismatch. Although 2014-2015 vaccines were not effective in preventing A(H3N2) infection, no increased susceptibility was detected among the repeatedly vaccinated.