Characteristics and outcomes of vaccinated and nonvaccinated patients hospitalized in a single Italian hub for COVID-19 during the Delta and Omicron waves in Northern Italy

International Journal of Infectious Diseases

Fausto Baldanti¹  Giuliana Lucia Esposito²  Alba Muzzi³  Anna Maria Grugnetti⁴  Viola Novelli⁴  Stefania Paolucci⁵  Marinella Daglio⁵  Sara Cutti⁵  Giulia Campanini⁵  Antonio Piralla⁵  Claudia Rona⁵  Emanuela Bertoli⁵  Federica Zavaglio⁶  Daniele Lilleri⁶  Marco Rissone⁶  Federica Giardina⁶  Carlo Marena⁶  Guglielmo Ferrari⁶  Francesca Rovida⁶  Giuseppina Grugnetti⁶  Anna Odone⁶ 

[1] Corresponding author: Daniele Lilleri, Microbiology and Virology Unit, Fondazione IRCCS Policlinico San Matteo, Viale Golgi 19, 27100 Pavia, Italy.;Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Pavia, Italy;Department of Public Health, Experimental and Forensic Medicine, Section of Hygiene, University of Pavia, Pavia, Italy;Specialization School in Microbiology and Virology, University of Pavia, Pavia, Italy;Medical Direction, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy;Microbiology and Virology Unit, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy;

关键词: SARS-CoV-2 infection;    COVID-19;    Vaccinated;    Delta variant;    Omicron variant;   

DOI  :  

来源: DOAJ

【 摘 要 】

Objective: We compared the characteristics and outcomes of vaccinated and nonvaccinated patients hospitalized with COVID-19. Design: We analyzed patients hospitalized in a COVID hub during three one-month periods: (i) October 15, 2020-November 15, 2020 (prevaccination peak); (ii) October 15, 2021-November 15, 2021 (Delta wave); (iii) December 15, 2021-January 15, 2022 (Omicron wave). To define the epidemiologic context, SARS-CoV-2 infection in healthcare workers was analyzed. Results: SARS-CoV-2 infection incidence in healthcare workers was 146 cases per 1000 persons in 2020 (prevaccination) and 67 in 2021 (postvaccination, when the Omicron variant caused most infections). There were 420 hospitalized patients in the prevaccination period, 51 during the Delta wave (52.1% vaccinated) and 165 during the Omicron wave (52.9% vaccinated). During the Delta wave, a significantly higher number of nonvaccinated (29.2%) than vaccinated patients (3.7%) were admitted to the intensive care unit (ICU) (p = 0.019). Nonvaccinated patients were younger and had a lower rate of concomitant medical conditions (53.2% vs 83.7%; p < 0.001) during the Omicron wave when 80% of patients admitted to ICU and all those who died were still infected by the Delta variant. Conclusions: Vaccine effectiveness in fragile individuals appears to be lower because of a faster immunity decline. However, the Omicron variant seems to cause less severe COVID-19.

【 授权许可】

Unknown