ABSTRACT
The use of vaccines has allowed the containment of coronavirus disease 2019 (COVID-19) at a global level. The present work aims to add data on vaccination by evaluating the level of neutralizing antibodies in individuals who have received a three-vaccination series. For this purpose, we ran a surveillance program directed at measuring the level of IgG Abs against the Receptor Binding Domain (RBD) and surrogate virus neutralizing Ab (sVNT) anti-SARS-CoV-2 in the serum of individuals undergoing vaccination. This study was performed on employees from the University of Rome Tor Vergata and healthcare workers from the University Hospital who received the Vaxzevria vaccine (n = 56) and Comirnaty vaccine (n = 113), respectively. After the second dose, an increase in both RBD and sVNT Ab values was registered. In individuals who received the Comirnaty vaccine, the antibody titer was about one order of magnitude higher after 6 months from the first dose. All participants in this study received the Comirnaty vaccine as the third dose, which boosted the antibody response. Five months after the third dose, nearly one year from the first injection, the antibody level was >1000 BAU/mL (binding antibody units/mL). According to the values reported in the literature conferring protection against SARS-CoV-2 infection, our data indicate that individuals undergoing three vaccine doses present a low risk of infection.
ABSTRACT
PURPOSE: To evaluate two different concentrations of contrast medium (CM) and two different acquisition techniques to obtain vascular images with multislice spiral CT (msCT). MATERIALS AND METHODS: Thirty patients referred for msCT examinations of the kidney or upper abdomen underwent evaluation of the abdominal aorta during the arterial phase, after giving their consent (GE Light Speed Plus). In the first part of the study (20 patients) the enhancement values measured at six different levels of the aortoiliac axis (celiac trunk, suprarenal aorta, subrenal aorta, aortal bifurcation, right iliac and left iliac) were compared after administering two different concentrations of iodinated contrast medium (300 and 370 mgI/ml) with two different acquisition techniques (HQ and HS). The flow rate was 3 ml/sec. In the second part of the study 10 patients were examined by changing the flow rate (2 and 4 ml/sec). Both quantity and quality assessments were conducted on axial images and on vascular reconstructions. RESULTS: In the first part of the study the best results were obtained with the 370 mgI/ml concentration and with the HQ acquisition technique (pitch 3, table feed 7.5 mm/rotation, gantry rotation speed 0.5 s). The quality of reconstructions gradually improved before reaching 240 HU, above which image quality remained constant. The patients examined with a flow rate of 2 ml/sec showed a poor image quality, unlike those examined with a flow rate of 4 ml/sec where we observed the maximum threshold values and constant optimal vascular opacification, with no significant differences from the patients studied at 3 ml/sec. CONCLUSIONS: Our results indicate that, albeit on a limited number of patients, a higher concentration of CM and the use of an HQ technique allow a high quality examination to be obtained. The HS technique yields results comparable to those obtained with higher concentrations.