COVID-19 vaccine effectiveness against hospitalization due to SARS-CoV-2: A test-negative design study based on Severe Acute Respiratory Infection (SARI) sentinel surveillance in Spain.

BACKGROUND: With the emergence of SARS-CoV-2, influenza surveillance systems in Spain were transformed into a new syndromic sentinel surveillance system. The Acute Respiratory Infection Surveillance System (SiVIRA in Spanish) is based on a sentinel network for acute respiratory infection (ARI) surveillance in primary care and a network of sentinel hospitals for severe ARI (SARI) surveillance in hospitals. METHODS: Using a test-negative design and data from SARI admissions notified to SiVIRA between January 1 and October 3, 2021, we estimated COVID-19 vaccine effectiveness (VE) against hospitalization, by age group, vaccine type, time since vaccination, and SARS-CoV-2 variant. RESULTS: VE was 89% (95% CI: 83-93) against COVID-19 hospitalization overall in persons aged 20 years and older. VE was higher for mRNA vaccines, and lower for those aged 80 years and older, with a decrease in protection beyond 3 months of completing vaccination, and a further decrease after 5 months. We found no differences between periods with circulation of Alpha or Delta SARS-CoV-2 variants, although variant-specific VE was slightly higher against Alpha. CONCLUSIONS: The SiVIRA sentinel hospital surveillance network in Spain was able to describe clinical and epidemiological characteristics of SARI hospitalizations and provide estimates of COVID-19 VE in the population under surveillance. Our estimates add to evidence of high effectiveness of mRNA vaccines against severe COVID-19 and waning of protection with time since vaccination in those aged 80 or older. No substantial differences were observed between SARS-CoV-2 variants (Alpha vs. Delta).

Factors associated with 30-day mortality in elderly inpatients with community acquired pneumonia during 2 influenza seasons.

Community-acquired pneumonia (CAP) refers to pneumonia unrelated to hospitals or extended-care facilities. The aim of this study was to determine factors associated with 30-day mortality in patients with CAP aged ≥ 65 y admitted to 20 hospitals in 7 Spanish regions during the 2013-14 and 2014-15 influenza seasons. Logistic regression was used to identify factors associated with 30-day mortality. The adjusted model included variables selected by backward elimination with a cut off of < 0.02. A total of 1928 CAP cases were recorded; 60.7% were male, 46.67% were aged 75-84 years, and 30-day mortality was 7.6% (n = 146). Pneumococcal vaccination had a significant protective effect (OR 0.68, 95% CI, 0.48-0.96; p = 0.03) and influenza vaccination in any 3 preceding seasons slight protective effect against CAP (OR 0.72, 95% CI, 0.51-1.02;p = 0.06). Factors significantly associated with 30-day mortality were having a degree of dependence (aOR 3.67, 95% CI, 2.34-5.75; p < 0,001); age ≥ 85 y (OR 3.01, 95% CI, 1.71-5.30; p < 0.001), liver impairment (aOR 2.41, 95% CI, 1.10-5.31; p = 0.03); solid organ neoplasm (aOR 2.24, 95% CI, 1.46-3.45; p < 0.001), impaired cognitive function (aOR 1.93, 95% CI, 1.22-3.05; p = 0.005), and ICU admittance (aOR2.56, 95% CI, 1.27-5.16; p = 0.009); length of stay (aOR 1.56, 95% CI, 1.02 - 2.40; p = 0.04) and cardio-respiratory resuscitation (aOR 7.75, 95% CI, 1.20 - 49.98; p = 0.03). No association was observed for other comorbidities such as chronic pulmonary obstructive disease (COPD) or heart conditions in the adjusted model. Offering both pneumococcal and influenza vaccination to the elderly may improve 30-day mortality in patients with CAP.

Cómo elaborar un protocolo de investigación en salud / How to elaborate a protocol on health research

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