Influenza Vaccine Effectiveness in the Netherlands from 2003/2004 through 2013/2014: The Importance of Circulating Influenza Virus Types and Subtypes

Abstract

Influenza vaccine effectiveness (IVE) varies over different influenza seasons and virus (sub)types/lineages. To assess the association between IVE and circulating influenza virus (sub)types/lineages, we estimated the overall and (sub)type specific IVE in the Netherlands. We conducted a test-negative case control study among subjects with influenza-like illness or acute respiratory tract infection consulting the Sentinel Practices over 11 influenza seasons (2003/2004 through 2013/2014) in the Netherlands. The adjusted IVE was estimated using generalized linear mixed modelling and multiple logistic regression. In seven seasons vaccine strains did not match the circulating viruses. Overall adjusted IVE was 40% (95% CI 18 to 56%) and 20% (95% CI -5 to 38%) when vaccine (partially)matched and mismatched the circulating viruses, respectively. When A(H3N2) was the predominant virus, IVE was 38% (95% CI 14 to 55%). IVE against infection with former seasonal A(H1N1) virus was 83% (95% CI 52 to 94%), and with B virus 67% (95% CI 55 to 76%). In conclusion IVE estimates were particularly low when vaccine mismatched the circulating viruses and A(H3N2) was the predominant influenza virus subtype. Tremendous effort is required to improve vaccine production procedure and to explore the factors that influence the IVE against A(H3N2) virus.

The association between influenza infections in primary care and intensive care admissions for severe acute respiratory infection (SARI): A modelling approach

“…However, direct comparison is difficult as the Belgian estimates are based on all hospitalizations instead of only ICU admissions, with a different SARI case definition than ours, and with a different healthcare system. Few Western European countries other than Belgium have SARI surveillance, although some countries monitor more specifically the number of laboratory‐confirmed influenza hospitalizations and ICU admissions; this narrower case definition shows lower incidences than reported for SARI 9,19‐21 …”

Impact of influenza vaccination programmes among the elderly population on primary care, Portugal, Spain and the Netherlands: 2015/16 to 2017/18 influenza seasons

“…Given that VC did not vary considerably in the three seasons, the main drivers for the differences in season-specific NAE would be the number of MAICC and the IVE estimates. Seasons with dominant influenza A(H3N2) circulation are reported to produce a high influenza burden in the elderly population [25], and often a limited IVE against subtype A(H3N2) [26,27]. In 2016/17, the IVE was below 10% in the three countries.…”

Impact of influenza vaccination in the Netherlands, 2007–2016: Vaccinees consult their general practitioner for clinically diagnosed influenza, acute respiratory infections, and pneumonia more often than non-vaccinees

“…Influenza A viruses caused the majority of laboratory-confirmed influenza cases in all seasons during the study period except in 2007–08, when 51% of cases were caused by the B/Yamagata virus lineage ( Table 1 ). Some level of antigenic and/or lineage-level mismatch between circulating influenza viral strains and those contained in the vaccine was observed in the majority seasons during the study period ( Table 1 ) [ 9 , 29 , 30 ].…”