3.1. Study Population

The study consisted of 25 males and 18 females with a mean age of 65 ± 17.0 years (mean ± sd). Among the selected patients, 10 (23%) had no comorbidities, whereas 33 (77%) had two or more comorbidities. The presence of comorbidities in patients admitted to the ED was statistically relevant (p = 0.0020). The most frequently encountered comorbidities were systemic arterial hypertension, cardiovascular disease, obesity, dyslipidemia, type 2 diabetes mellitus, and neoplastic disease which occurs during anti-cancer treatment.

We analyzed the main reasons for ED admission; 67% of patients were admitted for symptoms due to COVID-19, and among these, fever, sore throat, and cold were detected in 23% of cases, followed by dyspnea (21%) and abdominal or chest pain (23%).

The remaining 33% were admitted for other causes: 8% for trauma, 21% of cases presented other symptoms that were not attributable to COVID-19, and 4% had acute neurological syndrome, as reported in Figure 1. The proportion of patients admitted to the ED for COVID-19 related symptoms was statistically relevant (p = 0.0017).

At ED admission, patients had high median C-reactive Protein (CRP) levels (3.84 mg/dL, IQR 0.86–11.67—(normal values: ≤0.5 mg/dL), median values of leukocytes at 8.05 × 103/μL, IQR 6.69–10.64 (normal values: 4–11 × 103/μL) with a median neutrophil of 5.63 × 103/μL, IQR 4.29–7.95 (normal values: 2–7 × 103/μL), median lymphocyte values of 1.05 × 103/μL, IQR 0.66–1.51 (normal values: 1–3 × 103/μL), and a median high D-dimer of 1490 ng/mL, IQR 677–3380 (normal values:0–500 ng/mL).

Of the 43 patients who were included in the study, 22 (51%) patients were unvaccinated for SARS-CoV-2 or vaccinated with a single dose, and 21 (49%) had completed the vaccination course with two or three doses. Patients received mRNA vaccines from Comirnaty (BNT162b2) (Pfizer/BioNTech, Mainz, Germany/New York, NY, USA) or Spikewax (mRNA 1273) (Moderna TX, Cambridge, MA, USA). Of the latter 21 patients that were vaccinated, as many as 13 (52%) were admitted for trauma (fracture or accident) or for other symptoms that were not related to COVID-19 (renal colic, acute diverticulitis), whereas 8 (38%) were admitted as they presented a COVID-19-related symptomatology.

Of the 22 unvaccinated patients, only one patient (4.5%) was admitted for symptoms that could not be attributed to COVID-19 (dehydration and acute kidney failure in a patient with ileostomy), whereas the other 21 (94.5%) were admitted for COVID-19. Thus, 38% of the vaccinated presented a COVID-19 symptomatology, whereas among the unvaccinated, as many as 94.5% were admitted for presenting a COVID-19 symptomatology. The proportion of unvaccinated patients that were admitted to the ED for a COVID-19 symptomatology was statistically relevant (p < 0.0001).

After admission to the ED, 14/43 (32.5%) patients were discharged home. The proportion of patients needing hospital admission was statistically relevant (p = 0.013). Among the discharged patients, 7/14 (50%) were patients who were vaccinated with three doses of the vaccine, 1/14 (7%) were vaccinated with a single dose but had suffered from a previous SARS-CoV-2 infection, 1/14 (7%) were vaccinated with a single dose of the vaccine, and 5/14 (36%) were unvaccinated, as reported in Table 1. The proportion of vaccinated patients that was discharged home was statistically significant (p = 0.027).Among the unvaccinated patients, only 1/5 (20%) had a comorbidity (diabetes); the remaining 4/5 (80%) had no major comorbidities, as reported in Table 2. The patients who had received a single dose of vaccine presented no comorbidities, whereas the patients vaccinated with a single dose, and who had suffered a prior SARS-CoV-2 infection, were affected by hypertension. Among patients who had received three doses of the vaccine 1/7 (14%) had two comorbidities (diabetes and hypertension) and 1/7 (14%) reported a prior cerebral hemorrhage, resulting in hemiparesis (Table 2). After admission to the ED, 27/43 (63%) needed hospital admission and 2/43 (5%) required a stay in the Intensive Care Unit. Of these, 10/27 (37%) were patients that were vaccinated with three doses of the vaccine, 3/27 (11%) were vaccinated with two doses or with a single dose, but who had suffered from a previous SARS-CoV-2 infection, 1/27 (4%) were vaccinated with a single dose of the vaccine, and 13/27 (48%) were unvaccinated, as reported in Table 1. The correlation between patients’ comorbidities, their vaccination status, and their destiny after being admitted to the ED (either discharged home or admitted to hospital) was analyzed, as reported in Table 2. Among the unvaccinated patients who were discharged home, 1/5 (20%) were affected by diabetes, whereas among the patients who were discharged home and who had three doses of the vaccine, 1/7 (14%) had both diabetes and hypertension and 1/7 (14%) presented hemiparesis due to prior cerebral hemorrhage. Furthermore, one vaccinated patient with one dose plus infection was discharged home and was affected by hypertension. Regarding hospital admission, vaccinated patients who had three doses of the vaccine presented comorbidities in 7/10 (70%) of cases; they were affected by neoplastic disease in 3/10 (30%) of cases, diabetes plus hypertension and COPD in 1/10 (10%) of cases, cardiomiopathy plus hypertension in 1/10 (10%) of cases, and COPD in 2/10 (20%) of cases (Table 2). Among the unvaccinated patients needing hospital admission, comorbidities were present in 5/13 (38%) of cases; 1/13 (8%) had neoplastic disease, 3/13 (23%) had diabetes plus hypertension, and 1/13 (8%) had diabetes plus heart and renal failure (Table 2). One patient who had taken a single dose of the vaccine was affected by chronic heart failure, and three patients who had taken two doses of the vaccine, or who had taken one dose and had previously suffered from the SARS-CoV-2 infection, had hypertension, diabetes, and neoplastic disease, and therefore, they required hospital admission (Table 2). Finally, after being admitted to the ED two patients needed ICU admission, and they presented significant comorbidities; one suffered heart failure (50%) and the other suffered from diabetes plus heart and renal failure (50%). Neither patient survived, as shown in Table 2.