TY - JOUR AU - Schiaroli, Elisabetta AU - De Socio, Giuseppe Vittorio AU - Gidari, Anna AU - Malincarne, Lisa AU - Benedetti , Sara AU - Lanzi, Alessandra AU - Bastianelli, Sabrina AU - Pierucci, Sara AU - busti, Chiara AU - Francisci, Daniela PY - 2022/06/29 Y2 - 2024/03/28 TI - PRE AND POST-MONOCLONAL INFUSION NEUTRALIZING ACTIVITY IN A SUBGROUP OF PATIENTS TREATED IN THE PRESENCE OF TWO SARS-COV-2 DOMINANT VARIANT OF CONCERN (VOCS) AND AN ONGOING VACCINATION. OVERALL CLINICAL EFFICACY OF TWO MONOCLONAL ANTIBODIES ASSOCIATION IN UMBRIA JF - Mediterranean Journal of Hematology and Infectious Diseases JA - Mediterr J Hematol Infect Dis VL - 14 IS - 1 SE - Original Articles DO - 10.4084/MJHID.2022.050 UR - https://www.mjhid.org/mjhid/article/view/4940 SP - e2022050 AB - <p><strong><em>Background and Objective: </em></strong><strong>In</strong> <strong>patients with mild-to-moderate COVID-19 and at high risk of progression,</strong><strong> casirivimab/imdevimab and bamlanivimab/etesivimab were utilized in Umbria from late April to November 2021. This period was characterized by an initial prevalence of alpha (B1.1.1.7) and its progressive substitution with the delta variant (B1.617.2). Many delta infections occurred in patients already recently vaccinated.</strong></p><p><strong>Our study aimed to observe the clinical outcome of patients treated with mAbs associations in a subgroup in which viral isolation was obtained, the pre and post-infusion neutralizing antibody activity against their viral isolate.</strong></p><p><strong><em>Methods: </em></strong><strong>In this retrospective observational study, the clinical outcome before and 30 days after infusion, the baseline neutralizing activity of sera against their viral isolate, and the titers of neutralizing antibodies (NAbTs) one-hour post-infusion relative to the type of mAbs associations were evaluated.</strong></p><p><strong><em>Results: </em></strong><strong>Better efficacy of the mAbs combinations relative to monotherapy regarding global hospitalization (<em>p = 0.021</em>) and 30 days symptoms (p<em>&lt;0.001</em>) were seen. Infections after vaccination mostly occurred in the absence of</strong><strong> neutralizing antibody titers</strong><strong> (</strong><strong>NAbT)</strong><strong>. SARS-CoV-2 delta variants were isolated within 2-4 months from vaccinations without NAbTs, or in the presence of high specific neutralizing activity after 5-6 months. </strong><strong>NAbTs were higher after </strong><strong>casirivimab/imdevimab infusion (</strong><strong>p=0.001</strong><strong>). </strong></p><p><strong><em>Conclusions: </em></strong><strong>Alpha infections occurred prevalently in unvaccinated patients or after 5-6 months, while delta infections prevailed in vaccinated ones. A poor neutralizing activity in most of these patients was seen. A higher </strong><strong>NAbT after infusion of </strong><strong>casirivimab/imdevimab</strong><strong> was observed.</strong></p><p><strong> </strong></p> ER -