1 National Influenza Reference Laboratory, Infectious Diseases Department, National Institute of Health, Portugal;
2 Department of Epidemiology, National Institute of Health, Portugal;
3-13 Members of the Portuguese Laboratory Network for Diagnosis of Influenza Infection;
3 Hospital de São João, EPE;
4 Centro Hospitalar e Universitário de Coimbra, EPE ;
5 Hospital do Divino Espírito Santo de Ponta Delgada, E.P.E.;
6 Hospital do Santo Espírito de Angra do Heroísmo, E.P.E.;
7 Centro Hospitalar de Lisboa Central, E.P.E;
8 Instituto Português de Oncologia de Lisboa, Francisco Gentil, E.P.E.;
9 Centro Hospitalar da Cova da Beira, E.P.E.;
10 Centro Hospitalar de Setúbal, E.P.E.;
11 Laboratório Regional de Saúde Pública Dra. Laura Ayres- ARS Algarve;
12 Hospital do Espírito Santo, EPE - Évora;
13 Hospital Central do Funchal, E.P.E.
Divulgação:
ECDC Annual Influenza Meeting, Stockholm, Sweden, 10-12 June 2015. Poster
Resumo:
This study aims to assess the immunity for influenza seasonal viruses in a sample of 626 serum samples collected in June 2014, from all age groups, at 11 hospitals in Portugal, mainland and islands (Azores and Madeira). Evaluate the presence of cross- reactive antibody to the new A(H3) drift virus in a subset of 150 samples with HI titre ≥ 80, for A/Texas/50/2013. The prevalence of protective antibody titres, for all age groups, was 30.0% for A/California/7/2009, 40.0% for A/Texas/50/2012, 23.0% for B/Massachusetts/2/2012 and 9.0% for B/Brisbane/60/2008. For influenza A the protective antibodies seroprevalence were higher in children aged 5-14 years old and decreased with age, with an exception for A(H3) viruses in individuals aged over 65 years old. Regarding influenza B, the seroprotective antibodies had an increasing trend across the age groups, for both Yamagata and Victoria lineage. The seroprevalence results were also reflected by the pattern of geometric mean titres. Cross reactive antibodies to the new drifted A(H3) viruses were detected only in 46% of the patients that showed seroprotection for A(H3) vaccine virus, that is in line with a limited vaccine effectiveness for the majority of the A(H3) virus that circulated in 2014/2015 winter season.
Palavras Chave: Influenza, Antibodies