{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T00:25:07Z","timestamp":1760228707960,"version":"build-2065373602"},"reference-count":37,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2022,5,23]],"date-time":"2022-05-23T00:00:00Z","timestamp":1653264000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia (FCT) and the Fundo Social Europeu (FSE) Program","award":["2020.09390.BD"],"award-info":[{"award-number":["2020.09390.BD"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Vaccines against COVID-19 approved for use in the EU\/EEA have been shown to be highly effective against wild-type SARS-CoV-2. However, their effectiveness against new variants may be reduced. This study aims to evaluate the effectiveness of vaccines against COVID-19 in the prevention of symptomatic and severe disease, during pre- and post-omicron phases. Individuals who sought treatment at the emergency department of a Portuguese hospital with COVID-19-like disease and were tested for SARS-CoV-2 are the subjects of the study. Patients who received a positive result are considered cases, while those with negative results are the controls. The test-negative case\u2013control method is one of the study designs recommended by WHO to estimate the effectiveness of vaccines against COVID-19. The main advantage of this design is that it controls for the healthcare seeking bias, commonly present in traditional cohort and case\u2013control designs. This study may have broad implications for understanding the real-world performance of the COVID-19 vaccines at the local level, which may play a key role in promoting adherence to vaccination. Moreover, this study may contribute to inform decisions regarding booster doses and variant-specific vaccine formulations leading to the control of this and future pandemics.<\/jats:p>","DOI":"10.3390\/vaccines10050822","type":"journal-article","created":{"date-parts":[[2022,5,25]],"date-time":"2022-05-25T05:12:27Z","timestamp":1653455547000},"page":"822","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Evaluation of the Real-World Effectiveness of Vaccines against COVID-19 at a Local Level: Protocol for a Test-Negative Case\u2013Control Study"],"prefix":"10.3390","volume":"10","author":[{"given":"C\u00e1tia","family":"Brazete","sequence":"first","affiliation":[{"name":"EPIUnit\u2014Instituto de Sa\u00fade P\u00fablica, Universidade do Porto, 4050-600 Porto, Portugal"},{"name":"Unidade de Sa\u00fade P\u00fablica do Alto Minho, 4904-459 Viana do Castelo, Portugal"}]},{"given":"Marta","family":"Pinto","sequence":"additional","affiliation":[{"name":"Unidade de Investiga\u00e7\u00e3o Cl\u00ednica da ARS Norte, 4000-477 Porto, Portugal"},{"name":"Faculdade de Psicologia e Ci\u00eancias da Educa\u00e7\u00e3o, Universidade do Porto, 4200-135 Porto, Portugal"}]},{"given":"L\u00edgia","family":"S\u00e1","sequence":"additional","affiliation":[{"name":"Unidade de Sa\u00fade P\u00fablica do Alto Minho, 4904-459 Viana do Castelo, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7643-8963","authenticated-orcid":false,"given":"Ana","family":"Aguiar","sequence":"additional","affiliation":[{"name":"EPIUnit\u2014Instituto de Sa\u00fade P\u00fablica, Universidade do Porto, 4050-600 Porto, Portugal"},{"name":"Laborat\u00f3rio Para a Investiga\u00e7\u00e3o Integrativa e Translacional em Sa\u00fade Populacional (ITR), 4050-600 Porto, Portugal"}]},{"given":"Filipe","family":"Alves","sequence":"additional","affiliation":[{"name":"Unidade de Investiga\u00e7\u00e3o Cl\u00ednica da ARS Norte, 4000-477 Porto, Portugal"}]},{"given":"Raquel","family":"Duarte","sequence":"additional","affiliation":[{"name":"EPIUnit\u2014Instituto de Sa\u00fade P\u00fablica, Universidade do Porto, 4050-600 Porto, Portugal"},{"name":"Unidade de Investiga\u00e7\u00e3o Cl\u00ednica da ARS Norte, 4000-477 Porto, Portugal"},{"name":"Laborat\u00f3rio Para a Investiga\u00e7\u00e3o Integrativa e Translacional em Sa\u00fade Populacional (ITR), 4050-600 Porto, Portugal"},{"name":"Instituto de Ci\u00eancias Biom\u00e9dicas Abel Salazar, Universidade do Porto, 4050-303 Porto, Portugal"},{"name":"Servi\u00e7o de Pneumologia, Centro Hospitalar de Vila Nova de Gaia\/Espinho, 4434-502 Vila Nova de Gaia, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2022,5,23]]},"reference":[{"key":"ref_1","unstructured":"World Health Organization (2022, April 01). 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