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Nature: SARS-CoV-2 mRNA vaccine can quickly stabilize CD8+ T cells
Nature: SARS-CoV-2 mRNA vaccine can quickly stabilize CD8+ T cells.The SARS-CoV-2 spike mRNA vaccine began to mediate and prevent the occurrence of serious diseases as early as 10 days after the initial vaccination. At this time, it is difficult to detect neutralizing antibodies. Therefore, CD8+ T cells induced by the vaccine may be the main protective medium at this early stage.
August 12, 2021 / The SARS-CoV-2 spike mRNA vaccine began to mediate and prevent the occurrence of serious diseases as early as 10 days after the initial vaccination. At this time, it is difficult to detect neutralizing antibodies. Therefore, CD8+ T cells induced by the vaccine may be the main protective medium at this early stage.
However, compared with natural infections, the induction mechanism of the vaccine and its connection with other aspects of inducing immunity are still unclear.
In this study, the researchers conducted a continuous longitudinal analysis at the level of a single epitope from the booster vaccination process 3-4 months after vaccination to track the spike-specific CD8 + T cells and spike-specific cells induced by the bnt162b2 vaccine. The trajectory of sexual CD4 + T cells, B cells, antibodies and their neutral activity.
Studies have shown that one week after bnt162b2 vaccination, when circulating CD4+ T cells and neutralizing antibodies are only weakly detected, a stable and fully functional CD8+ T cell response is stimulated. The booster vaccination induced the production of highly differentiated effector CD8+ T cells; however, the functional capacity and memory precursor T cell pool were not affected. Compared with CD8+ T cells, the peaks of neutralizing antibodies and antigen-specific B cells shifted to the periphery were detected for the first time after boosting vaccination.
This is likely to indicate the maturity of the secondary lymphatic organ (SLO) response, which is then released into the circulation. After enhanced vaccination, there are highly cross-neutralizing antibodies in the serum, which obviously increases a major protective effect mechanism, which is above the spike-specific CD8+ T cell response of early metastasis.
The humoral and CD8+ T cell responses may be coordinated by the early-induced spike response CD4+ T cells, these cells undergo limited expansion after the second vaccination, and promote cell coordination.
In addition, the fully functional vaccine-induced early memory CD8+ T cells monitor the periphery of SARS-CoV-2 for at least the first few months. The functional effects of spike-specific early memory CD8+ T cells are similar after vaccination and natural infection until 3-4 months of enhancement/symptoms appear.
However, compared with natural infection, after vaccination, the early memory pool of spike-specific CD8+ T cells showed a different distribution of memory T cell subsets, which may affect the long-term maintenance characteristics.
This difference may be due to the difference in the time and location of antigen contact after vaccination and infection, and the different inflammatory response, which indicates that compared with natural infection, the memory spike-specific CD8+ T cells in the early stage after vaccination CD38 expression is low.
Figure Early memory CD8+ T cells after immunity and natural infection
In short, this study has deeply analyzed the protective mechanism of the bnt162b2 vaccine, which has implications for the development of new vaccine strategies against emerging pathogens and cancer.
In order to assess the lifespan of CD8+ T cell immunity, it is clear that follow-up studies including a larger cohort of vaccinators and SARS-CoV-2 recovery period are needed.
The research is limited to the specific adaptive immunity of circulating spikes, and does not involve the local immunity of the respiratory tract where the virus enters the site.
(source:internet, reference only)