RESUMEN
Coronavirus disease 2019 (COVID-19) threatens global public health and economy. In order to develop safe and effective vaccines, suitable animal models must be established. Here we report the rapid adaption of SARS-CoV-2 in BALB/c mice, based on which a convenient, economical and effective animal model was developed. Specifically, we found that mouse-adapted SARS-CoV-2 at passage 6 (MACSp6) efficiently infected both aged and young wild-type BALB/c mice, resulting in moderate pneumonia as well as inflammatory responses. The elevated infectivity of MACSp6 in mice could be attributed to the substitution of a key residue (N501Y) in the receptorbinding domain (RBD). Using this novel animal model, we further evaluated the in vivo protective efficacy of an RBD-based SARS-CoV-2 subunit vaccine, which elicited highly potent neutralizing antibodies and conferred full protection against SARS-CoV-2 MACSp6 challenge. This novel mouse model is convenient and effective in evaluating the in vivo protective efficacy of SARS-CoV-2 vaccine. SummaryThis study describes a unique mouse model for SARS-CoV-2 infection and confirms protective efficacy of a SARS-CoV-2 RBD subunit vaccine.
RESUMEN
Objective To evaluate the hearing effects in hearing impaired children using FM system .Methods The FM listening evaluation for children questionnaire was used to evaluate 27 cases with sensorineural hearing loss who were fitted hearing aids or cochlear implants ,or using FM system .The auditory skills of the patients were evaluated in four kinds of listening environments :quiet ,noise ,auditory only and distance by this questionnaire . Each question required a subjective score based on the child's response .The higher the scores the better the results . The age range of the participants was 3 .48~5 .50 .On an average ,their experience of using hearing instruments was 2 .56 ± 0 .97 years .Results With local microphones only ,the total score was 67 .55% ;in quiet situation ,the score was 85 .33% ;in noise ,the score was 60 .54% ;with visual only ,the score was 69 .58% and in distance ,the score was 69 .5% .With frequency modulated + microphone ,the total score was 84 .35% ,in quiet situation ,the score was 94 .89% ,in noise ,the score was 81 .35% ,with visual only ,the score was 83 .56% ,and in distance ,and the score was 83 .29% .The score of the subjects with hearing instruments only in quiet was significant higher than those of in noise and long distance without eye clue situation(F=49 .53 ,P<0 .05) .The score of the subjects was significant improved after using FM system (P<0 .05) .The score of the subjects with hearing instruments and FM system in quiet was also significant higher than those of in noise ,long distance ,without eye clue situation(F=24 . 80 ,P<0 .05) .Conclusion FM system could improve the listening experience in hearing impaired children in a com‐plex environment .However ,processes and programs for preschool hearing impaired children should be further standardized and improved when fitting FM system ,as findings of variability in questionnaire performance .
