The impact of the SARS-CoV-2 vaccine on innate immunity is not well understood. However, it has played a pivotal role in reducing COVID-19 severity and mortality. Recent findings have revealed that vaccine efficacy is influenced not only by the effective activation of adaptive immunity, but also by the modulation of innate immunity. This study evaluates the natural killer (NK) cell response and its relationship with type I interferon (IFN-I) gene expression in SARS-CoV-2-infected patients who had previously received the anti-spike vaccine, as well as in unvaccinated patients. Vaccinated individuals showed a higher frequency of NK NK CD56dim CD16- cells and increased IFN-α2 and IFN-ω mRNA expression (p < 0.05). By contrast, unvaccinated patients displayed a predominance of NK CD56dim CD16+ cells and reduced IFN-I gene expression (p < 0.05). A positive correlation was found between IFN-I levels and the frequency of NK CD56dim CD16- cells and a negative correlation between IFN-I levels and NK CD56dim CD16+ cells. Furthermore, despite having more comorbidities, vaccinated patients had faster SARS-CoV-2 clearance, which reinforces the immunological advantage conferred by vaccination. Together, these findings suggest that the SARS-CoV-2 vaccine can modify the innate immune response by enhancing the NK cell response and increasing the magnitude of IFN-I production during SARS-CoV-2 infection.

The impact of the SARS-CoV-2 vaccine on innate immunity is not well understood. However, it has played a pivotal role in reducing COVID-19 severity and mortality. Recent findings have revealed that vaccine efficacy is influenced not only by the effective activation of adaptive immunity, but also by the modulation of innate immunity. This study evaluates the natural killer (NK) cell response and its relationship with type I interferon (IFN-I) gene expression in SARS-CoV-2-infected patients who had previously received the anti-spike vaccine, as well as in unvaccinated patients. Vaccinated individuals showed a higher frequency of NK NK CD56dim CD16- cells and increased IFN-α2 and IFN-ω mRNA expression (p < 0.05). By contrast, unvaccinated patients displayed a predominance of NK CD56dim CD16+ cells and reduced IFN-I gene expression (p < 0.05). A positive correlation was found between IFN-I levels and the frequency of NK CD56dim CD16- cells and a negative correlation between IFN-I levels and NK CD56dim CD16+ cells. Furthermore, despite having more comorbidities, vaccinated patients had faster SARS-CoV-2 clearance, which reinforces the immunological advantage conferred by vaccination. Together, these findings suggest that the SARS-CoV-2 vaccine can modify the innate immune response by enhancing the NK cell response and increasing the magnitude of IFN-I production during SARS-CoV-2 infection.

The impact of the SARS-CoV-2 vaccine on innate immunity is not well understood. However, it has played a pivotal role in reducing COVID-19 severity and mortality. Recent findings have revealed that vaccine efficacy is influenced not only by the effective activation of adaptive immunity, but also by the modulation of innate immunity. This study evaluates the natural killer (NK) cell response and its relationship with type I interferon (IFN-I) gene expression in SARS-CoV-2-infected patients who had previously received the anti-spike vaccine, as well as in unvaccinated patients. Vaccinated individuals showed a higher frequency of NK CD56 dimCD16 - cells and increased IFN-α2 and IFN-ω mRNA expression (p < 0.05). By contrast, unvaccinated patients displayed a predominance of NK CD56 dimCD16 + cells and reduced IFN-I gene expression (p < 0.05). A positive correlation was found between IFN-I levels and the frequency of NK CD56 dimCD16 - cells and a negative correlation between IFN-I levels and NK CD56 dimCD16 + cells. Furthermore, despite having more comorbidities, vaccinated patients had faster SARS-CoV-2 clearance, which reinforces the immunological advantage conferred by vaccination. Together, these findings suggest that the SARS-CoV-2 vaccine can modify the innate immune response by enhancing the NK cell response and increasing the magnitude of IFN-I production during SARS-CoV-2 infection.

Considering the efficacy of monoclonal antibodies (mAbs) directed against the Spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in reducing disease severity, the aim of this study was to investigate the innate immune response before and after mAbs treatment in 72 vaccinated and 31 unvaccinated SARS-CoV-2 patients. Type I interferon (IFN-I) signature and cytokines genes were evaluated by real time RT-PCR. The vaccinated patients had increased negative rate of SARS-CoV-2 RT/real-time PCR tests as compared to unvaccinated ones after mAbs treatment. Unvaccinated patients but also those that resulted negative for serum anti-S antibodies despite vaccination had lower IFN-I and higher IFN-I related genes and cytokines mRNAs levels as compared to vaccinated individuals before mAbs. In addition, patients with low anti-S antibody titer showed immune genes expression levels between those found in negative and patients with high titer of anti-S antibodies. Changes in IFN-I pathway and cytokines levels were observed in unvaccinated patients after mAbs treatment, while the expression of most of the type I IFN genes and cytokines analysed, except for ISGs and IL-10 mRNAs, remained unchanged vaccinated patients. These data suggest that mAbs treatment is associated to a different virological and immunological response in SARS-CoV-2 infected patients according to their vaccination status and related anti-S antibodies titers.