Effectiveness of COVID-19 vaccines in preventing SARS-CoV-2 infection and hospitalisation, Navarre, Spain, January to April 2021
Iván Martínez‐Baz, Ana Miqueleiz, Itziar Casado, Ana Navascués, Camino Trobajo‐Sanmartín, Cristina Burgui, Marcela Guevara, Carmen Ezpeleta, Jesús Castilla, Working Group for the Study of COVID-19 in Navarra
Abstract
COVID-19 vaccine effectiveness was evaluated in close contacts of cases diagnosed during January-April 2021. Among 20,961 contacts, 7,240 SARS-CoV-2 infections were confirmed, with 5,467 being symptomatic and 559 leading to hospitalisations. Non-brand-specific one and two dose vaccine effectiveness were respectively, 35% (95% confidence interval (CI): 25 to 44) and 66% (95% CI: 57 to 74) against infections, 42% (95% CI: 31 to 52) and 82% (95% CI: 74 to 88) against symptomatic infection, and 72% (95% CI: 47 to 85) and 95% (95% CI: 62 to 99) against COVID-19 hospitalisation. The second dose significantly increased effectiveness. Findings support continuing complete vaccination.