ABSTRACT
Background: Coronavirus disease 2019 has been characterized by the rapidity of global transmission and the development of diagnostic reagents and vaccines. Aim: the aim of the study was to evaluate SARSCoV-2 humoral immunoresponse after mRNA anti-spike vaccine (BNT162b2 / Pfizer) administration in two cohorts of healthcare professionals at the INT Cancer Center -IRCCS 'Fondazione Pascale': previously exposed and not exposed to SARS-CoV-2 subjects. Materials and methods: 35 healthcare workers with a previous documented history of SARS-CoV-2 infection and 158 healthcare workers without, were enrolled after a written informed consent. Specific anti-RBD (receptor-binding domain) titers against trimeric spike glycoprotein (S) of SARS-CoV-2 were determined by Roche Elecsys Anti-SARS-CoV-2 S immunoassay in serum samples after 1 dose of vaccine in previously exposed subjects and after the first and the second dose in not previously exposed individuals. Geometric mean titers and relative fold changes (FC) were calculated. Results: both previously exposed and not exposed subjects developed significant immune responses to SARS-CoV-2 after the administration of 1 and 2 doses of vaccine, respectively. Anti-S antibody responses to the first dose of vaccine were significantly higher in previously SARS-CoV-2-exposed subjects in comparison to titers of not exposed subjects after the first dose (p <0.001), as well as the second dose of vaccine (p <0.001). FC for workers previously exposed to SARS-CoV-2 were very modest, given the high basal antibody titer, as well as the upper limit imposed by the method. Conversely, for naïve subjects, mean FC following the first dose was low (1.6), reaching 3.8 FC only in 72 (45.6%) subjects following the second dose (η3.1 in 19.0%).Conclusions: the results showed that, as early as the first dose, SARS-CoV-2-exposed individuals developed a remarkable immune response in comparison to those not exposed, justifying the administration of only one dose in previously exposed subjects. Nevertheless, in 19.0% of not previously exposed subjects, FC after the second dose showed a potential susceptibility to further SARS-CoV-2 infection, suggesting the possibility of administration of a third dose of vaccine in selected less responsive cases.
ABSTRACT
Background and Aim: As of 22 June 2020, Italy had 238.499cases of Severe Acute Respiratory Syndrome Coronavirus 2(SARS-CoV-2) infections, with about 35.000 deaths. A single-center observational cohort study was conducted to evaluate epidemiological, demographic, clinical and laboratory data of SARS-CoV-2patients who were admitted to the sub-intensive therapy unit ofthe COVID Unit Hospital F. Miulli (Acquaviva delle Fonti, Bari, Italy),from Mar 17, 2020 to May 17, 2020.Materials and Methods: Demographic data, symptoms, laboratory values, comorbidities, treatments, and clinical outcomes wereall collected and analysed. Results: A total of 143 SARS-CoV-2 patients, 60.4% males, meanage 68 yrs , were included. Twenty-seven patients (19%) had clinical signs of severe pneumonia and 6.3% had an ARDS, ICU admissions were 2.9%. The most represented comorbidities were:chronic heart failure (10.3%), diabetes (15.5%), chronic obstructive pulmonary disease (17.8%), cancer (13.2%), kidney chronicfailure (28.2%). The used drugs have been distributed as follows:lopinavir/ritonavir (30.4%), hydroxychloroquine (67.8%), steroid(21.2%), tocilizumab (4%). Length of stay was 21 days and theaverage negative time of the second nasopharyngeal swab was18 days. In our study, a total of 20 patients (13.9%) died, withmean age 86 yrs .Conclusions: Our findings show that SARS-CoV-2 infection maybe severe, requiring intensive care admission, expecially in olderpatients and in those with comorbidities.