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Browsing by Author "Dijkstra, Frederika"

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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.
    2018-06Journal article Open access Show more
  • 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.
    2024-07-01Journal article Open access Show more
  • 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.
    2024-06-04Journal article Open access Show more
  • 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.
    2019-09-17Journal article Open access Show more
  • Effectiveness of XBB.1.5 Vaccines Against Symptomatic SARS‐CoV‐2 Infection in Older Adults During the JN.1 Lineage‐Predominant Period, European VEBIS Primary Care Multicentre Study, 20 November 2023–1 March 2024
    Publication . Merdrignac, Lore; Laniece Delaunay, Charlotte; Verdasca, Nuno; Vega‐Piris, Lorena; O'Donnell, Joan; Sève, Noémie; Trobajo‐Sanmartín, Camino; Buda, Silke; Hooiveld, Mariëtte; Rodrigues, Ana Paula; Túri, Gergő; Latorre‐Margalef, Neus; Mlinarić, Ivan; Lazar, Mihaela; Maurel, Marine; Castrillejo, Daniel; Bennett, Charlene; Rameix‐Welti, Marie‐Anne; Martínez‐Baz, Iván; Dürrwald, Ralf; Meijer, Adam; Melo, Aryse; Oroszi, Beatrix; Hagey, Tove Samuelsson; Kurečić Filipović, Sanja; Dijkstra, Frederika; Gómez, Verónica; Bacci, Sabrina; Kaczmarek, Marlena; Kissling, Esther; VEBIS Primary Care Vaccine Effectiveness Group
    We estimated XBB.1.5 vaccine effectiveness (VE) against symptomatic SARS-CoV-2 infection among adults aged ≥65 years during the 2023/2024 JN.1 lineage-predominant period in a European multi-country test-negative case–control study at primary care level. We estimated VE adjusted by study site, age, sex, chronic conditions and onset date. We included 220 cases and 1733 controls. The VE was 48% (95% CI: 12–71), 23% (95% CI: −11–48) and 5% (95% CI: −92–56) among those with symptom onset 1–5, 6–11, and ≥12weeks after vaccination, respectively. XBB.1.5 vaccine provided short and moderate protection against JN.1 symptomatic infection.
    2024-11-10Journal article Open access Show more
  • Exploring the effect of clinical case definitions on influenza vaccine effectiveness estimation at primary care level: Results from the end-of-season 2022–23 VEBIS multicentre study in Europe
    Publication . Maurel, Marine; Mazagatos, Clara; Goerlitz, Luise; Oroszi, Beatrix; Hooiveld, Mariette; Machado, Ausenda; Domegan, Lisa; Ilić, Maja; Popescu, Rodica; Sève, Noémie; Martínez-Baz, Iván; Larrauri, Amparo; Buda, Silke; Túri, Gergő; Meijer, Adam; Gómez, Verónica; O'Donnell, Joan; Mlinarić, Ivan; Timnea, Olivia; Diez, Ana Ordax; Dürrwald, Ralf; Horváth, Judit Krisztina; Dijkstra, Frederika; Rodrigues, Ana Paula; McKenna, Adele; Filipović, Sanja Kurečić; Lazar, Mihaela; Kaczmarek, Marlena; Bacci, Sabrina; Kissling, Esther; VEBIS study team
    Background: Within influenza vaccine effectiveness (VE) studies at primary care level with a laboratory-confirmed outcome, clinical case definitions for recruitment of patients can vary. We used the 2022-23 VEBIS primary care European multicentre study end-of-season data to evaluate whether the clinical case definition affected IVE estimates. Methods: We estimated VE using a multicentre test-negative case-control design. We measured VE against any influenza and influenza (sub)types, by age group (0-14, 15-64, ≥65 years) and by influenza vaccine target group, using logistic regression. We estimated IVE among patients meeting the European Union (EU) acute respiratory infection (ARI) case definition and among those meeting the EU influenza-like illness (ILI) case definition, including only sites providing information on specific symptoms and recruiting patients using an ARI case definition (as the EU ILI case definition is a subset of the EU ARI one). Results: We included 24 319 patients meeting the EU ARI case definition, of whom 21 804 patients (90 %) meet the EU ILI case definition, for the overall pooled VE analysis against any influenza. The overall and influenza (sub)type-specific VE varied by ≤2 % between EU ILI and EU ARI populations. Discussion: Among all analyses, we found similar VE estimates between the EU ILI and EU ARI populations, with few (10%) additional non-ILI ARI patients recruited. These results indicate that VE in the 2022-23 influenza season was not affected by use of a different clinical case definition for recruitment, although we recommend investigating whether this holds true for next seasons.
    2024-05-03Journal article Open access Show more
  • Impact of influenza vaccination programmes among the elderly population on primary care, Portugal, Spain and the Netherlands: 2015/16 to 2017/18 influenza seasons
    Publication . Machado, Ausenda; Mazagatos, Clara; Dijkstra, Frederika; Kislaya, Irina; Gherasim, Alin; McDonald, Scott A.; Kissling, Esther; Valenciano, Marta; Meijer, Adam; Hooiveld, Mariëtte; Nunes, Baltazar; Larrauri, Amparo
    To increase the acceptability of influenza vaccine, it is important to quantify the overall benefits of the vaccination programme.AimTo assess the impact of influenza vaccination in Portugal, Spain and the Netherlands, we estimated the number of medically attended influenza-confirmed cases (MAICC) in primary care averted in the seasons 2015/16 to 2017/18 among those ≥ 65 years.We used an ecological approach to estimate vaccination impact. We compared the number of observed MAICC (n) to the estimated number that would have occurred without the vaccination programme (N). To estimate N, we used: (i) MAICC estimated from influenza surveillance systems, (ii) vaccine coverage, (iii) pooled (sub)type-specific influenza vaccine effectiveness estimates for seasons 2015/16 to 2017/18, weighted by the proportion of virus circulation in each season and country. We estimated the number of MAICC averted (NAE) and the prevented fraction (PF) by the vaccination programme. The annual average of NAE in the population ≥ 65 years was 33, 58 and 204 MAICC per 100,000 in Portugal, Spain and the Netherlands, respectively. On average, influenza vaccination prevented 10.7%, 10.9% and 14.2% of potential influenza MAICC each season in these countries. The lowest PF was in 2016/17 (4.9-6.1%) with an NAE ranging from 24 to 69 per 100,000. Our results suggest that influenza vaccination programmes reduced a substantial number of MAICC. Together with studies on hospitalisations and deaths averted by influenza vaccination programmes, this will contribute to the evaluation of the impact of vaccination strategies and strengthen public health communication.
    2019-11-07Journal article Open access Show more
  • Influenza vaccine effectiveness in Europe: Results from the 2022–2023 VEBIS (Vaccine Effectiveness, Burden and Impact Studies) primary care multicentre study
    Publication . Maurel, Marine; Pozo, Francisco; Pérez‐Gimeno, Gloria; Buda, Silke; Sève, Noémie; Oroszi, Beatrix; Hooiveld, Mariette; Gómez, Verónica; Domegan, Lisa; Martínez‐Baz, Iván; Ilić, Maja; Carnahan, Anna Sara; Mihai, Maria Elena; Martínez, Ana; Goerlitz, Luise; Enouf, Vincent; Horváth, Judit Krisztina; Dijkstra, Frederika; Rodrigues, Ana Paula; Bennett, Charlene; Trobajo‐Sanmartín, Camino; Mlinarić, Ivan; Latorre‐Margalef, Neus; Ivanciuc, Alina; Lopez, Aurora; Dürrwald, Ralf; Falchi, Alessandra; Túri, Gergő; Meijer, Adam; Melo, Aryse; O'Donnell, Joan; Castilla, Jesús; Vučina, Vesna Višekruna; Hagey, Tove Samuelsson; Lazar, Mihaela; Kaczmarek, Marlena; Bacci, Sabrina; Kissling, Esther; VEBIS Study Team
    Background: Influenza A(H3N2) viruses dominated early in the 2022-2023 influenza season in Europe, followed by higher circulation of influenza A(H1N1)pdm09 and B viruses. The VEBIS primary care network estimated the influenza vaccine effectiveness (VE) using a multicentre test-negative study. Materials and methods: Primary care practitioners collected information and specimens from patients consulting with acute respiratory infection. We measured VE against any influenza, influenza (sub)type and clade, by age group, by influenza vaccine target group and by time since vaccination, using logistic regression. Results: We included 38 058 patients, of which 3786 were influenza A(H3N2), 1548 influenza A(H1N1)pdm09 and 3275 influenza B cases. Against influenza A(H3N2), VE was 36% (95% CI: 25-45) among all ages and ranged between 30% and 52% by age group and target group. VE against influenza A(H3N2) clade 2b was 38% (95% CI: 25-49). Overall, VE against influenza A(H1N1)pdm09 was 46% (95% CI: 35-56) and ranged between 29% and 59% by age group and target group. VE against influenza A(H1N1)pdm09 clade 5a.2a was 56% (95% CI: 46-65) and 79% (95% CI: 64-88) against clade 5a.2a.1. VE against influenza B was 76% (95% CI: 70-81); overall, 84%, 72% and 71% were among 0-14-year-olds, 15-64-year-olds and those in the influenza vaccination target group, respectively. VE against influenza B with a position 197 mutation of the hemagglutinin (HA) gene was 79% (95% CI: 73-85) and 90% (95% CI: 85-94) without this mutation. Conclusion: The 2022-2023 end-of-season results from the VEBIS network at primary care level showed high VE among children and against influenza B, with lower VE against influenza A(H1N1)pdm09 and A(H3N2).
    2024-01-10Journal article Open access Show more
  • Interim 2023/24 influenza A vaccine effectiveness: VEBIS European primary care and hospital multicentre studies, September 2023 to January 2024
    Publication . Maurel, Marine; Howard, Jennifer; Kissling, Esther; Pozo, Francisco; Pérez-Gimeno, Gloria; Buda, Silke; Sève, Noémie; McKenna, Adele; Meijer, Adam; Rodrigues, Ana Paula; Martínez-Baz, Iván; Mlinarić, Ivan; Latorre-Margalef, Neus; Túri, Gergő; Lazăr, Mihaela; Mazagatos, Clara; Echeverria, Aitziber; Abela, Stephen; Bourgeois, Marc; Machado, Ausenda; Dürrwald, Ralf; Petrović, Goranka; Oroszi, Beatrix; Jancoriene, Ligita; Marin, Alexandru; Husa, Petr; Duffy, Roisin; Dijkstra, Frederika; Gallardo García, Virtudes; Goerlitz, Luise; Enouf, Vincent; Bennett, Charlene; Hooiveld, Mariëtte; Guiomar, Raquel; Trobajo-Sanmartín, Camino; Višekruna Vučina, Vesna; Samuelsson Hagey, Tove; Lameiras Azevedo, Ana Sofía; Castilla, Jesús; Xuereb, Gerd; Delaere, Bénédicte; Gómez, Verónica; Tolksdorf, Kristin; Bacci, Sabrina; Nicolay, Nathalie; Kaczmarek, Marlena; Rose, Angela MC; European IVE group
    Influenza A viruses circulated in Europe from September 2023 to January 2024, with influenza A(H1N1)pdm09 predominance. We provide interim 2023/24 influenza vaccine effectiveness (IVE) estimates from two European studies, covering 10 countries across primary care (EU-PC) and hospital (EU-H) settings. Interim IVE was higher against A(H1N1)pdm09 than A(H3N2): EU-PC influenza A(H1N1)pdm09 IVE was 53% (95% CI: 41 to 63) and 30% (95% CI: −3 to 54) against influenza A(H3N2). For EU-H, these were 44% (95% CI: 30 to 55) and 14% (95% CI: −32 to 43), respectively.
    2024-02-22Journal article Open access Show more
  • Measuring the impact of influenza vaccination programmes among the elderly population in Spain, the Netherlands and Portugal, 2015-2018
    Publication . Mazagatos, Clara; Machado, Ausenda; Dijkstra, Frederika; Kissling, Esther; Larrauri, Amparo; Kislaya, Irina; van Gageldonk-Lafeber, Rianne; Gherasim, Alin; Nunes, Baltazar; McDonald, Scott; Rose, Angie; Valenciano, Marta
    Measuring the number of influenza-associated events prevented by influenza vaccination among the elderly in the European Union would allow a better understanding of the overall impact of influenza vaccination programmes, particularly in seasons with low influenza vaccine effectiveness (IVE). This study measured the number of medically attended influenza-confirmed cases in primary care (MAICC) among those ≥65 years averted by influenza vaccination programmes in Spain (SP), the Netherlands (NL) and Portugal (PT), from 2015 to 2018.
    2019-01Conference object Unknown Show more