Neutralizing-antibody-independent SARS-CoV-2 control correlated with intranasal-vaccine-induced CD8+ T cell responses

Effective vaccines are essential for the control of the coronavirus disease 2019 (COVID-19) pandemic. Currently developed vaccines inducing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S)-antigen-specific neutralizing antibodies (NAbs) are effective, but the appearance of NAb-resistant S variant viruses is of great concern. A vaccine inducing S-independent or NAb-independent SARS-CoV-2 control may contribute to containment of these variants. Here, we investigate the efficacy of an intranasal vaccine expressing viral non-S antigens against intranasal SARS-CoV-2 challenge in cynomolgus macaques. Seven vaccinated macaques exhibit significantly reduced viral load in nasopharyngeal swabs on day 2 post-challenge compared with nine unvaccinated controls. The viral control in the absence of SARS-CoV-2-specific NAbs is significantly correlated with vaccine-induced, viral-antigen-specific CD8⁺ T cell responses. Our results indicate that CD8⁺ T cell induction by intranasal vaccination can result in NAb-independent control of SARS-CoV-2 infection, highlighting a potential of vaccine-induced CD8⁺ T cell responses to contribute to COVID-19 containment.

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Anti-SARS-CoV-2 efficacy of an intranasal S-free vaccine is shown in macaques

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The SARS-CoV-2 control is associated with vaccine-induced CD8⁺ T cell responses

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Vaccine induction of CD8⁺ T cells can result in neutralization-free viral control

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Vaccine-induced CD8⁺ T cells may contribute to SARS-CoV-2 variant control

Clinical evaluation of a potassium nitrate dentifrice for the treatment of dentinal hypersensitivity

The effectiveness of a 5% potassium nitrate dentifrice as a daily home treatment for dentinal hypersensitivity was evaluated in a double-blind study in 36 Japanese subjects who complained of cold and/or tactile hypersensitivity. The subjects were divided into 2 groups, with 18 being given a 5% potassium nitrate dentifrice (treated group) and the other 18 a vehicle paste (control group). Both groups were instructed to brush their teeth 2 x a day. The hypersensitivity levels of the affected teeth were assessed by 2 stimuli, one tactile and the other cold air, and by the perception of pain. The results of all 3 assessment methods indicated that the potassium nitrate dentifrice significantly decreased the level of hypersensitivity at weeks 4, 8, and 12. In the treated group, a rapid decrease of positive scores for both the cold air stimulus and the subjective symptoms appeared from week 2. Although a significant decrease of the assessment score was also observed in the control group, the reduction rate of the score was much greater in the treated group by all 3 assessment methods at weeks 4, 8, and 12. Complete relief of subjective symptoms throughout the 12 weeks' examination was noted in 67% of the subjects in the treated group, but in only 6% in the control group. These results suggest the usefulness of a 5% potassium nitrate dentifrice in Japanese patients with dentinal hypersensitivity.