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Percorrer por autor "Kissling, Esther"

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  • 2015/16 I-MOVE/I-MOVE+ multicentre case control study in Europe: moderate vaccine effectiveness estimates against influenza A(H1N1)pdm09 and low estimates against lineage mismatched influenza B among children
    Publication . Kissling, Esther; Valenciano, Marta; Pozo, Francisco; Vilcu, Ana-Maria; Reuss, Annicka; Rizzo, Caterina; Larrauri, Amparo; Horváth, Judit Krisztina; Brytting, Mia; Domegan, Lisa; Korczyńska, Monika; Meijer, Adam; Machado, Ausenda; Ivanciuc, Alina; Višekruna Vučina, Vesna; van der Werf, Sylvie; Schweiger, Brunhilde; Bella, Antonino; Gherasim, Alin; Ferenczi, Annamária; Zakikhany, Katherina; O Donnell, Joan; Paradowska-Stankiewicz, Iwona; Dijkstra, Frederika; Guiomar, Raquel; Lazar, Mihaela; Kurečić Filipović, Sanja; Johansen, Kari; Moren, Alain; I-MOVE/I-MOVE+ study team
    Background:During the 2015/16 influenza season in Europe, the co-circulating influenza viruses were A(H1N1)pdm09 and B/Victoria, which was antigenically distinct from the B/Yamagata component in the trivalent influenza vaccine. Methods:We used the test negative design in a multicentre case–control study in twelve European countries to measure 2015/16 influenza vaccine effectiveness (VE) against medically-attended influenza-like illness (ILI) laboratory-confirmed as influenza. General practitioners swabbed a systematic sample of consulting ILI patients ainfluenza Vaccinend a random sample of influenza positive swabs were sequenced. We calculated adjusted VE against influenza A(H1N1)pdm09, A(H1N1)pdm09 genetic group 6B.1 and influenza B overall and by age group. Results: We included 11,430 ILI patients, of which 2272 were influenza A(H1N1)pdm09 and 2901 were influenza B cases. Overall VE against influenza A(H1N1)pdm09 was 32.9% (95% CI: 15.5-46.7). Among those aged 0–14, 15–64 and ≥65  years VE against A(H1N1)pdm09 was 31.9% (95% CI: -32.3-65.0), 41.4% (95%CI: 20.5-56.7) and 13.2% (95% CI: -38.0-45.3) respectively. Overall VE against influenza A(H1N1)pdm09 genetic group 6B.1 was 32.8% (95%CI: -4.1-56.7). Among those aged 0–14, 15–64 and ≥65 years VE against influenza B was -47.6% (95%CI: -124.9-3.1), 27.3% (95%CI: -4.6-49.4), and 9.3% (95%CI: -44.1-42.9) respectively. Conclusions: VE against influenza A(H1N1)pdm09 and its genetic group 6B.1 was moderate in children and adults, and low among individuals ≥65  years. VE against influenza B was low and heterogeneous among age groups. More information on effects of previous vaccination and previous infection are needed to understand the VE results against influenza B in the context of a mismatched vaccine.
    2018-06Artigo científico Acesso aberto Ver mais
  • Comparison of two methods for the estimation of COVID-19 vaccine effectiveness of the autumnal booster within the VEBIS-EHR network in 2022/23
    Publication . Monge, Susana; Humphreys, James; Nicolay, Nathalie; Braeye, Toon; Van Evercooren, Izaak; Hansen, Christian Holm; Emborg, Hanne-Dorthe; Fabiani, Massimo; Sacco, Chiara; Castilla, Jesús; Martínez-Baz, Iván; de Gier, Brechje; Hahné, Susan; Hinta Meijerink; Kristoffersen, Anja Bråthen; Machado, Ausenda; Soares, Patricia; Fontán-Vela, Mario; Nardone, Anthony; Kissling, Esther; Nunes, Baltazar; VEBIS-Lot 4 working group
    Within an infrastructure to monitor vaccine effectiveness (VE) against hospitalization due to COVID-19 and COVID-19 related deaths from November 2022 to July 2023 in seven countries in real-world conditions (VEBIS network), we compared two approaches: (a) estimating VE of the first, second or third COVID-19 booster doses administered during the autumn of 2022, and (b) estimating VE of the autumn vaccination dose regardless of the number of prior doses (autumnal booster approach). Retrospective cohorts were constructed using Electronic Health Records at each participating site. Cox regressions with time-changing vaccination status were fit and site-specific estimates were combined using random-effects meta-analysis. VE estimates with both approaches were mostly similar, particularly shortly after the start of the vaccination campaign, and showed a similar timing of VE waning. However, autumnal booster estimates were more precise and showed a clearer trend, particularly compared to third booster estimates, as calendar time increased after the vaccination campaign and during periods of lower SARS-CoV-2 activity. Moreover, the decrease in protection by increasing calendar time was more clear and precise than when comparing protection by number of doses. Therefore, estimating VE under an autumnal booster framework emerges as a preferred method for future monitoring of COVID-19 vaccination campaigns.
    2025-03-17Artigo científico Acesso aberto Ver mais
  • COVID-19 Vaccine Effectiveness Against Medically Attended Symptomatic SARS-CoV-2 Infection Among Target Groups in Europe, October 2024-January 2025, VEBIS Primary Care Network
    Publication . Delaunay, Charlotte Laniece; Verdasca, Nuno; Monge, Susana; Domegan, Lisa; Sève, Noémie; Buda, Silke; Meijer, Adam; Lucaccioni, Héloïse; Torrijos, Miriam López; McKenna, Adele; Enouf, Vincent; Dürrwald, Ralf; In't Velt, Eline; Laiglesia, Mª Ángel de Valcárcel; Bennett, Charlene; Masse, Shirley; Erdwiens, Annika; Hooiveld, Mariette; Mlinarić, Ivan; Túri, Gergő; Rodrigues, Ana Paula; Martínez-Baz, Iván; Lazar, Mihaela; Latorre-Margalef, Neus; Borges, Vitor; Kaczmarek, Marlena; Bacci, Sabrina; Kissling, Esther; European primary care VE group
    We estimated the effectiveness of 2024/25 COVID-19 vaccination against medically attended SARS-CoV-2 infection in Europe, among target groups. We included 3204 patients (8/139 cases vaccinated: 6%; 517/3065 controls vaccinated: 17%) from a multicentre, test-negative design study at primary care level. Vaccine effectiveness was 66% (95% CI: 34-85) overall, 73% (95% CI: 21-94) and 54% (95% CI: -3 to 83) in the first and second months post-vaccination, respectively. Overall vaccine effectiveness was 67% (95% CI: 33-86) among older adults (≥ 60 or ≥ 65 years). This relatively high COVID-19 VE (compared with previous seasons), as well as trends by time since vaccination, should be confirmed with additional data, as sample size was low.
    2025-05-21Artigo científico Acesso aberto Ver mais
  • COVID-19 vaccine effectiveness against symptomatic infection with SARS-CoV-2 BA.1/BA.2 lineages among adults and adolescents in a multicentre primary care study, Europe, December 2021 to June 2022
    Publication . Lanièce Delaunay, Charlotte; Martínez-Baz, Iván; Sève, Noémie; Domegan, Lisa; Mazagatos, Clara; Buda, Silke; Meijer, Adam; Kislaya, Irina; Pascu, Catalina; Carnahan, AnnaSara; Oroszi, Beatrix; Ilić, Maja; Maurel, Marine; Melo, Aryse; Sandonis Martín, Virginia; Trobajo-Sanmartín, Camino; Enouf, Vincent; McKenna, Adele; Pérez-Gimeno, Gloria; Goerlitz, Luise; de Lange, Marit; Rodrigues, Ana Paula; Lazar, Mihaela; Latorre-Margalef, Neus; Túri, Gergő; Castilla, Jesús; Falchi, Alessandra; Bennett, Charlene; Gallardo, Virtudes; Dürrwald, Ralf; Eggink, Dirk; Guiomar, Raquel; Popescu, Rodica; Riess, Maximilian; Horváth, Judit Krisztina; Casado, Itziar; García, M. del Carmen; Hooiveld, Mariëtte; Machado, Ausenda; Bacci, Sabrina; Kaczmarek, Marlena; Kissling, Esther
    Background: Scarce European data in early 2021 suggested lower vaccine effectiveness (VE) against SARS-CoV-2 Omicron lineages than previous variants. Aim: We aimed to estimate primary series (PS) and first booster VE against symptomatic BA.1/BA.2 infection and investigate potential biases. Methods: This European test-negative multicentre study tested primary care patients with acute respiratory symptoms for SARS-CoV-2 in the BA.1/BA.2-dominant period. We estimated PS and booster VE among adults and adolescents (PS only) for all products combined and for Comirnaty alone, by time since vaccination, age and chronic condition. We investigated potential bias due to correlation between COVID-19 and influenza vaccination and explored effect modification and confounding by prior SARS-CoV-2 infection. Results: Among adults, PS VE was 37% (95% CI: 24–47%) overall and 60% (95% CI: 44–72%), 43% (95% CI: 26–55%) and 29% (95% CI: 13–43%) < 90, 90–179 and ≥ 180 days post vaccination, respectively. Booster VE was 42% (95% CI: 32–51%) overall and 56% (95% CI: 47–64%), 22% (95% CI: 2–38%) and 3% (95% CI: −78% to 48%), respectively. Primary series VE was similar among adolescents. Restricting analyses to Comirnaty had little impact. Vaccine effectiveness was higher among older adults. There was no signal of bias due to correlation between COVID-19 and influenza vaccination. Confounding by previous infection was low, but sample size precluded definite assessment of effect modification. Conclusion: Primary series and booster VE against symptomatic infection with BA.1/BA.2 ranged from 37% to 42%, with similar waning post vaccination. Comprehensive data on previous SARS-CoV-2 infection would help disentangle vaccine- and infection-induced immunity.
    2024-03-28Artigo científico Acesso aberto Ver mais
  • COVID-19 Vaccine Effectiveness in Autumn and Winter 2022 to 2023 Among Older Europeans
    Publication . Laniece Delaunay, Charlotte; Mazagatos, Clara; Martínez-Baz, Iván; Túri, Gergő; Goerlitz, Luise; Domegan, Lisa; Meijer, Adam; Rodrigues, Ana Paula; Sève, Noémie; Ilić, Maja; Latorre-Margalef, Neus; Lazar, Mihaela; Maurel, Marine; Melo, Aryse; Andreu Ivorra, Blanca; Casado, Itziar; Horváth, Judit Krisztina; Buda, Silke; Bennett, Charlene; de Lange, Marit; Guiomar, Raquel; Enouf, Vincent; Mlinarić, Ivan; Samuelsson Hagey, Tove; Dinu, Sorin; Rumayor, Mercedes; Castilla, Jesús; Oroszi, Beatrix; Dürrwald, Ralf; O’Donnell, Joan; Hooiveld, Mariëtte; Gómez, Verónica; Falchi, Alessandra; Kurečić Filipović, Sanja; Dillner, Lena; Popescu, Rodica; Bacci, Sabrina; Kaczmarek, Marlena; Kissling, Esther; Gallardo García, Virtudes; Perez Morilla, Esteban; Pedrosa Corral, Irene; García Vázquez, Miriam; Milagro-Beamonte, Ana; Fernandez Ibañez, Ana; Margolles Martins, Mario; Giménez Duran, Jaume; Sastre Palou, Bartolomé; López Causapé, Carla; Viloria Raymundo, Luis Javier; Vega Alonso, Tomás; Ordax Díez, Ana; Lozano Alonso, Jose Eugenio; Rojo Bello, Silvia; Mendioroz, Jacobo; Basile, Luca; Martínez Mateo, Ana Isabel; Ruiz de Porras, Carlota; Moya Garcés, Alba; Marcos, Mª Ángeles; López Maside, Aurora; Botella Quijal, Francesc; Miralles Espi, Maite; Andreu Salete, Cristina; García Rodríguez, María del Carmen; Linares, Juan Antonio; García Comas, Luis; Barranco, Mª Isabel; Chirlaque, María-Dolores; Moreno Docón, Antonio; Ramos Marín, Violeta; Castrillejo, Daniel; Gómez Anés, Atanasio; Larrauro, Amparo; Pérez-Gimeno, Gloria; Lozano Álvarez, Marcos; Vega, Lorena; Galindo, Silvia; Puma, Tania; Monge, Susana; Pozo, Francisco; Casas, Inmaculada; Sandonis, Virginia; Vázquez-Morón, Sonia; Echeverría, Aitziber; Trobajo-Sanmartín, Camino; García Cenoz, Manuel; Ezpeleta, Guillermo; Ezpeleta, Carmen; Navascués, Ana; Krisztalovics, Katalin; Mucsányiné Juhász, Krisztina; Kristóf, Katalin; Preuss, Ute; Wedde, Marianne; Biere, Barbara; Reiche, Janine; Oh, Djin-Ye; McKenna, Adele; Connell, Jeff; Joyce, Michael; Bagheri, Mariam; Bos, Sanne; van den Brink, Sharon; Dijkstra, Frederika; Eggink, Dirk; van Gageldonk-Lafeber, Rianne; Goderski, Gabriel; Herrebrugh, Chantal; Jenniskens, Liz; Reukers, Daphne; Sluimer, John; Sprong, Tara; Teirlinck, Anne; Veldhijzen, Nienke; van der Burgh, Ruben; Kager, Cathrien; Klinkhamer, Mayra; Knottnerus, Bart; Riethof, Marloes; van den Broek, Ruud; Wortel, Safira; Machado, Ausenda; Kislaya, Irina; Aniceto, Carlos; Gomes, Licínia; Verdasca, Nuno; Henriques, Camila; Dias, Daniela; Lança, Miguel; Blanchon, Thierry; Guerrisi, Caroline; Renard, Aubane; Launay, Titouan; Masse, Shirley; Chazelle, Marie; Ferenčak, Ivana; Kaić, Bernard; Višekruna Vučina, Vesna; Čusek Adamić, Katica; Kosanović Ličina, Mirjana Lana; Lakošeljac, Danijela; Mihin Huskić, Ivana; Nonković, Diana; Carnahan, Annasara; Hansson-Pihlainen, Eva; Arvesen, Elin; Nid, Nora; Hansen, Anna-Lena; Andersson, Emmi; Dillner, Lena; Jidovu, Adrian; Timnea, Olivia Carmen; Pascu, Cătălina; Oprea, Mihaela; Bistriceanu, Iulia; Ivanciuc, Alina; Mihai, Maria Elena; VEBIS Primary Care Vaccine Effectiveness Group
    Key Points: - Question: What was the effectiveness of COVID-19 vaccines administered in autumn and winter 2022 to 2023 against symptomatic SARS-CoV-2 infection among people aged 60 years or older in Europe, and how did different exposed or reference groups affect effectiveness? - Findings: In this case-control study of 9308 primary care patients at 11 European sites, within 3 months of vaccination, all COVID-19 vaccine effectiveness (CVE) estimates were 29% to 39% against SARS-CoV-2 viruses and 44% to 52% against the XBB variants. All point estimates decreased by time after vaccination, with no vaccine protection after 6 months. - Meaning: Findings of this study suggest that COVID-19 vaccination campaigns should precede peaks in SARS-CoV-2 incidence and that effectiveness of new vaccines against emerging variants should be continually monitored using seasonal CVE approaches.
    2024-07-01Artigo científico Acesso aberto Ver mais
  • COVID-19 vaccine effectiveness in the paediatric population aged 5-17 years: a multicentre cohort study using electronic health registries in six European countries, 2021 to 2022
    Publication . Soares, Patricia; Machado, Ausenda; Nicolay, Nathalie; Monge, Susana; Sacco, Chiara; Hansen, Christian Holm; Meijerink, Hinta; Martínez-Baz, Iván; Schmitz, Susanne; Humphreys, James; Fabiani, Massimo; Echeverria, Aitziber; AlKerwi, Ala'a; Nardone, Anthony; Mateo-Urdiales, Alberto; Castilla, Jesús; Kissling, Esther; Nunes, Baltazar; VEBIS-Lot 4 working group
    Background: During the first year of the COVID-19 pandemic, vaccination programmes targeted children and adolescents to prevent severe outcomes of SARS-CoV-2 infection. Aim: To estimate COVID-19 vaccine effectiveness (VE) against hospitalisation due to COVID-19 in the paediatric population, among those with and without previously documented SARS-CoV-2 infection. Methods: We established a fixed cohort followed for 12 months in Denmark, Norway, Italy, Luxembourg, Navarre (Spain) and Portugal using routine electronic health registries. The study commenced with paediatric COVID-19 vaccination campaign at each site between June 2021 and January 2022. The outcome was hospitalisation with a laboratory-confirmed SARS-CoV-2 infection or COVID-19 as the main diagnosis. Using Cox proportional hazard models, VE was estimated as 1 minus the confounder-adjusted hazard ratio of COVID-19 hospitalisation between vaccinated and unvaccinated. A random-effects meta-analysis was used to pool VE estimates. Results: We included 4,144,667 5-11-year-olds and 3,861,841 12-17-year-olds. In 12-17-year-olds without previous infection, overall VE was 69% (95% CI: 40 to 84). VE declined with time since vaccination from 77% ≤ 3 months to 48% 180-365 days after immunisation. VE was 94% (95% CI: 90 to 96), 56% (95% CI: 3 to 80) and 41% (95% CI: -14 to 69) in the Delta, Omicron BA.1/BA.2 and BA.4/BA.5 periods, respectively. In 12-17-year-olds with previous infection, one dose VE was 80% (95% CI: 18 to 95). VE estimates were similar for 5-11-year-olds but with lower precision. Conclusion: Vaccines recommended for 5-17-year-olds provided protection against COVID-19 hospitalisation, regardless of a previously documented infection of SARS-CoV-2, with high levels of protection in the first 3 months of the vaccination.
    2025-02-27Artigo científico Acesso aberto Ver mais
  • Early 2016/17 vaccine effectiveness estimates against influenza A(H3N2): I-MOVE multicentre case control studies at primary care and hospital levels in Europe
    Publication . Kissling, Esther; Rondy, Marc; I-MOVE/I-MOVE+ study team
    We measured early 2016/17 season influenza vaccine effectiveness (IVE) against influenza A(H3N2) in Europe using multicentre case control studies at primary care and hospital levels. IVE at primary care level was 44.1%, 46.9% and 23.4% among 0-14, 15-64 and ≥ 65 year-olds, and 25.7% in the influenza vaccination target group. At hospital level, IVE was 2.5%, 7.9% and 2.4% among ≥ 65, 65-79 and ≥ 80 year-olds. As in previous seasons, we observed suboptimal IVE against influenza A(H3N2).
    2017-02-16Artigo científico Acesso aberto Ver mais
  • Effectiveness of complete primary vaccination against COVID-19 at primary care and community level during predominant Delta circulation in Europe: multicentre analysis, I-MOVE-COVID-19 and ECDC networks, July to August 2021
    Publication . Kissling, Esther; Hooiveld, Mariëtte; Martínez-Baz, Iván; Mazagatos, Clara; William, Naoma; Vilcu, Ana-Maria; Kooijman, Marjolein N.; Ilić, Maja; Domegan, Lisa; Machado, Ausenda; de Lusignan, Simon; Lazar, Mihaela; Meijer, Adam; Brytting, Mia; Casado, Itziar; Larrauri, Amparo; Murray, Josephine-L.K.; Behillil, Sylvie; de Gier, Brechje; Mlinarić, Ivan; O’Donnell, Joan; Rodrigues, Ana Paula; Tsang, Ruby; Timnea, Olivia; de Lange, Marit; Riess, Maximilian; Castilla, Jesús; Pozo, Francisco; Hamilton, Mark; Falchi, Alessandra; Knol, Mirjam J.; Kurečić Filipović, Sanja; Dunford, Linda; Guiomar, Raquel; Cogdale, Jade; Cherciu, Carmen; Jansen, Tessa; Enkirch, Theresa; Basile, Luca; Connell, Jeff; Gómez, Verónica; Sandonis Martín, Virginia; Bacci, Sabrina; Rose, Angela M.C.; Pastore Celentano, Lucia; Valenciano, Marta; I-MOVE-COVID-19 and ECDC primary care study teams
    Introduction: In July and August 2021, the SARS-CoV-2 Delta variant dominated in Europe. Aim: Using a multicentre test-negative study, we measured COVID-19 vaccine effectiveness (VE) against symptomatic infection. Methods: Individuals with COVID-19 or acute respiratory symptoms at primary care/community level in 10 European countries were tested for SARS-CoV-2. We measured complete primary course overall VE by vaccine brand and by time since vaccination. Results: Overall VE was 74% (95% CI: 69–79), 76% (95% CI: 71–80), 63% (95% CI: 48–75) and 63% (95% CI: 16–83) among those aged 30–44, 45–59, 60–74 and ≥ 75 years, respectively. VE among those aged 30–59 years was 78% (95% CI: 75–81), 66% (95% CI: 58–73), 91% (95% CI: 87–94) and 52% (95% CI: 40–61), for Comirnaty, Vaxzevria, Spikevax and COVID-19 Vaccine Janssen, respectively. VE among people 60 years and older was 67% (95% CI: 52–77), 65% (95% CI: 48–76) and 83% (95% CI: 64–92) for Comirnaty, Vaxzevria and Spikevax, respectively. Comirnaty VE among those aged 30–59 years was 87% (95% CI: 83–89) at 14–29 days and 65% (95% CI: 56–71%) at ≥ 90 days between vaccination and onset of symptoms. Conclusions: VE against symptomatic infection with the SARS-CoV-2 Delta variant varied among brands, ranging from 52% to 91%. While some waning of the vaccine effect may be present (sample size limited this analysis to only Comirnaty), protection was 65% at 90 days or more between vaccination and onset.
    2022-05-26Artigo científico Acesso aberto Ver mais
  • Effectiveness of COVID-19 vaccines administered in the 2023 autumnal campaigns in Europe: Results from the VEBIS primary care test-negative design study, September 2023–January 2024
    Publication . Laniece Delaunay, Charlotte; Melo, Aryse; Maurel, Marine; Mazagatos, Clara; Goerlitz, Luise; O’Donnell, Joan; Oroszi, Beatrix; Sève, Noémie; Rodrigues, Ana Paula; Martínez-Baz, Iván; Meijer, Adam; Mlinarić, Ivan; Latorre-Margalef, Neus; Lazăr, Mihaela; Pérez-Gimeno, Gloria; Dürrwald, Ralf; Bennett, Charlene; Túri, Gergő; Rameix-Welti, Marie-Anne; Guiomar, Raquel; Castilla, Jesús; Hooiveld, Mariëtte; Kurečić Filipović, Sanja; Samuelsson Hagey, Tove; Dijkstra, Frederika; Borges, Vitor; Ramos Marín, Violeta; Bacci, Sabrina; Kaczmarek, Marlena; Kissling, Esther; European primary care VE group
    In autumn 2023, European vaccination campaigns predominantly administered XBB.1.5 vaccine. In a European multicentre study, we estimated 2023 COVID-19 vaccine effectiveness (VE) against laboratory-confirmed symptomatic infection at primary care level between September 2023 and January 2024. Using a testnegative case–control design, we estimated VE in the target group for COVID-19 vaccination overall and by time since vaccination. We included 1057 cases and 4397 controls. Vaccine effectiveness was 40 % (95 % CI: 26–53 %) overall, 48 % (95 % CI: 31–61 %) among those vaccinated < 6 weeks of onset and 29 % (95 % CI: 3–49 %) at 6–14 weeks. Our results suggest that COVID-19 vaccines administered to target groups during the autumn 2023 campaigns showed clinically significant effectiveness against laboratory-confirmed, medically attended symptomatic SARS-CoV-2 infection in the 3 months following vaccination. A longer study period will allow for further variant-specific COVID-19 VE estimates, better understanding decline in VE and informing booster administration policies.
    2024-06-04Artigo científico Acesso aberto Ver mais
  • Effectiveness of influenza vaccine against influenza A in Europe in seasons of different A(H1N1)pdm09 and the same A(H3N2) vaccine components (2016-17 and 2017-18)
    Publication . Kissling, Esther; Pozo, Francisco; Buda, Silke; Vilcu, Ana-Maria; Rizzo, Caterina; Gherasim, Alin; Krisztina Horváth, Judit; Brytting, Mia; Domegan, Lisa; Meijer, Adam; Paradowska-Stankiewicz, Iwona; Machado, Ausenda; Višekruna Vučina, Vesna; Lazar, Mihaela; Johansen, Kari; Dürrwald, Ralf; van der Werf, Sylvie; Bella, Antonino; Larrauri, Amparo; Ferenczi, Annamária; Zakikhany, Katherina; O'Donnell, Joan; Dijkstra, Frederika; Bogusz, Joanna; Guiomar, Raquel; Kurečić Filipović, Sanja; Pitigoi, Daniela; Penttinen, Pasi; Valenciano, Marta; Gomez, Veronica; Kislaya, Irina; Nunes, Baltazar; I-MOVE/I-MOVE+ study team
    Introduction: Influenza A(H3N2) viruses predominated in Europe in 2016–17. In 2017–18 A(H3N2) and A(H1N1)pdm09 viruses co-circulated. The A(H3N2) vaccine component was the same in both seasons; while the A(H1N1)pdm09 component changed in 2017–18. In both seasons, vaccine seed A(H3N2) viruses developed adaptations/alterations during propagation in eggs, impacting antigenicity. Methods: We used the test-negative design in a multicentre primary care case-control study in 12 European countries to measure 2016–17 and 2017–18 influenza vaccine effectiveness (VE) against laboratory-confirmed influenza A(H1N1)pdm09 and A(H3N2) overall and by age group. Results: During the 2017–18 season, the overall VE against influenza A(H1N1)pdm09 was 59% (95% CI: 47–69). Among those aged 0–14, 15–64 and ≥65 years, VE against A(H1N1)pdm09 was 64% (95% CI: 37–79), 50% (95% CI: 28–66) and 66% (95% CI: 42–80), respectively. Overall VE against influenza A(H3N2) was 28% (95% CI: 17–38) in 2016–17 and 13% (95% CI: -15 to 34) in 2017–18. Among 0–14-year-olds VE against A(H3N2) was 28% (95%CI: -10 to 53) and 29% (95% CI: -87 to 73), among 15–64-year-olds 34% (95% CI: 18–46) and 33% (95% CI: -3 to 56) and among those aged ≥65 years 15% (95% CI: -10 to 34) and -9% (95% CI: -74 to 32) in 2016–17 and 2017–18, respectively. Conclusions: Our study suggests the new A(H1N1)pdm09 vaccine component conferred good protection against circulating strains, while VE against A(H3N2) was <35% in 2016–17 and 2017–18. The egg propagation derived antigenic mismatch of the vaccine seed virus with circulating strains may have contributed to this low effectiveness. A(H3N2) seed viruses for vaccines in subsequent seasons may be subject to the same adaptations; in years with lower than expected VE, recommendations of preventive measures other than vaccination should be given in a timely manner.
    2019-09-17Artigo científico Acesso aberto Ver mais