ABSTRACT
Objective: To evaluate the elicitation and the duration of anti-SARS-Cov-2 neutralizing antibodies (nAbs) after BNT162b2 vaccination in subjects with Multiple Sclerosis (swMS) naïve or under therapy compared to Healthy Subjects (HS). Background: Questions have raised about anti-SARS-CoV2 vaccine efficacy in subjects under immunosuppressive/immunomodulatory therapies such as swMS. These therapies are often associated with qualitative and quantitative changes of the immune system, and thus may have implications on the efficacy of anti-SARS-CoV-2 vaccine due to a different elicitation of the immune response. The neutralizing capacity of vaccine-induced antibodies (Abs), as well as the duration of these nAbs is a fundamental issue to be addressed for the comprehension of how swMS respond to anti-SARS-CoV-2 vaccine. Design/Methods: Sera were collected from 71 swMS and 20 HS, before, 1 and 6 months after vaccination with BNT162b2 vaccine. Anti-SARS-CoV-2 nAbs were measured with an ELISA test that detects IgG directed toward the Receptor Binding Domain (RBD) localized on the Spike (S) protein of SARS-CoV-2, and by means of an in vitro antiviral test using SARS-CoV-2 pseudovirions engineered with the S protein. Results: At multivariable analysis, swMS showed a lower anti-RBD IgG production one month after vaccination with respect to HS. This was mainly due to a lower anti-RBD IgG production in swMS under anti-CD20, Fingolimod or Cladribine treatment. Conclusions: Anti-SARS-CoV2 vaccination elicits a comparable humoral immune response in swMS and HS, with the exception of swMS undergoing some immunodepleting therapies. The comprehension of the better timing of vaccination in these patients will be useful for the induction of a proper Abs response.
ABSTRACT
The airborne transmission of SARS-CoV-2 remains surprisingly controversial; indeed, health and regulatory authorities still require direct proof of this mode of transmission. To close this gap, we measured the viral load of SARS-CoV-2 of an infected subject in a hospital room (through an oral and nasopharyngeal swab), as well as the airborne SARS-CoV-2 concentration in the room resulting from the person breathing and speaking. Moreover, we simulated the same scenarios to estimate the concentration of RNA copies in the air through a novel theoretical approach and conducted a comparative analysis between experimental and theoretical results. Results showed that for an infected subject's viral load ranging between 2.4 × 106 and 5.5 × 106 RNA copies mL-1, the corresponding airborne SARS-CoV-2 concentration was below the minimum detection threshold when the person was breathing, and 16.1 (expanded uncertainty of 32.8) RNA copies m-3 when speaking. The application of the predictive approach provided concentrations metrologically compatible with the available experimental data (i.e. for speaking activity). Thus, the study presented significant evidence to close the gap in understanding airborne transmission, given that the airborne SARS-CoV-2 concentration was shown to be directly related to the SARS-CoV-2 emitted. Moreover, the theoretical analysis was shown to be able to quantitatively link the airborne concentration to the emission.