Characterization of a new SARS-CoV-2 variant that emerged in Brazil.

The spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) plays a key role in viral infectivity. It is also the major antigen stimulating the host's protective immune response, specifically, the production of neutralizing antibodies. Recently, a new variant of SARS-CoV-2 possessing multiple mutations in the S protein, designated P.1, emerged in Brazil. Here, we characterized a P.1 variant isolated in Japan by using Syrian hamsters, a well-established small animal model for the study of SARS-CoV-2 disease (COVID-19). In hamsters, the variant showed replicative abilities and pathogenicity similar to those of early and contemporary strains (i.e., SARS-CoV-2 bearing aspartic acid [D] or glycine [G] at position 614 of the S protein). Sera and/or plasma from convalescent patients and BNT162b2 messenger RNA vaccinees showed comparable neutralization titers across the P.1 variant, S-614D, and S-614G strains. In contrast, the S-614D and S-614G strains were less well recognized than the P.1 variant by serum from a P.1-infected patient. Prior infection with S-614D or S-614G strains efficiently prevented the replication of the P.1 variant in the lower respiratory tract of hamsters upon reinfection. In addition, passive transfer of neutralizing antibodies to hamsters infected with the P.1 variant or the S-614G strain led to reduced virus replication in the lower respiratory tract. However, the effect was less pronounced against the P.1 variant than the S-614G strain. These findings suggest that the P.1 variant may be somewhat antigenically different from the early and contemporary strains of SARS-CoV-2.

A Pilot Study Investigating Neuropsychological Consultation as an Intervention for Persistent Postconcussive Symptoms in a Pediatric Sample.

OBJECTIVE: To examine the efficacy of a one-time neuropsychological consultation as an intervention for youth with persistent postconcussive symptoms following mild traumatic brain injury. STUDY DESIGN: Using a prospective interrupted time series design, we enrolled 80 patients aged 8-17 years referred consecutively for clinical neuropsychological consultation. Patients needed to have sustained injury between 2 and 12 months prior to enrollment. Parent and child postconcussive symptom ratings were used as the primary outcome measures and were collected at 6 time points, 3 before the neuropsychological consultation and 3 after. Repeated measure ANOVA was used to estimate the magnitude of change in symptom ratings before and after the neuropsychological intervention. RESULTS: The decrease in symptoms for the week prior to consultation was nonsignificant by both child (P = .63) and parent (P = .19) report. In contrast, for both reporters, the decrease in symptoms at 1 week and 3 months postconsultation was significant (P < .0001). The difference in reported change was also significant when comparing the week before the intervention to the 3 months after (child: P < .0001; parent: P = .0009). CONCLUSIONS: Postconcussive symptoms decreased significantly following the neuropsychological consultation. The primary limitation of the study is that it lacked randomization and a control group. The results warrant further research into the benefits of neuropsychological consultation after mild traumatic brain injury and provide justification for clinical providers to consider referring to neuropsychologists in the face of persistent postconcussive symptoms.