A research team from the Johns Hopkins University School of Medicine has published a new study that suggests specific Covid-19 Vaccines can be protected against different types of coronavirus.1 These include varieties first identified in the UK and South Africa.
The study examined the response to the SARS-CoV-2 virus and three other common cold coronaviruses after administration of a mRNA-based COVID-19 vaccine. Blood samples from 30 healthcare workers who did not test positive for COVID-19 were tested previously and after they received the Pfizer-BioNTech or Moderna COVID-19 vaccine.
The study model focused on coronavirus surface proteins – spike proteins – that help viruses gain access to host cells and clear them. A class of immune cells called helper T cells or CD4 + T cells recognize these viral proteins in coronavirus -infected cells and encourage cell destruction. The COVID-19-based mRNA vaccine contains an internal code that allows healthy cells to produce these spike proteins. It promotes the growth of a CD4 + T cell response specific to coronavirus spike proteins. The CD4 + T cell response was assessed using blood samples before and after vaccination to demonstrate the effectiveness of the vaccine.
As expected by the research group, vaccinated participants showed a significantly greater CD4 + T cell response to SARS-CoV-2 after vaccination. But other coronavirus strains have also been tested with the hope of understanding the effectiveness of the COVID-19 vaccine against the strains.
SARS-CoV-2 varieties differ in some building blocks of their protein spikes. In testing the common cold coronaviruses HCoV-NL63, HCoV-229E, and HCoV-OC43, the researchers measured the level of resistance given when exposed to different ones.
The research team observed a broad T cell response to the SARS-CoV-2 virus, and they identified 23 different viral proteins targeted to coronavirus-specific T cells.
Of these 23 peptides, four can be modified differently in UK B.1.1.7 and South Africa B.1.351. It suggests that 19 other peptides (building blocks) are always among coronaviruses and targeted to vaccine-induced CD4 + T cells when exposed to the SARS-CoV-2 virus and other variants. which is different.
Results from a study at the Johns Hopkins School of Medicine reiterated the importance of the CD4 + T cell response to SARS-Cov-2 and the common cold coronaviruses. They tested the T cell response to spike proteins in patients recovered from COVID-19 as well as uninfected individuals. In 65% of participants, memory CD4 + T cells recognized protein spikes from SARS-CoV-2 and at least one other common cold coronavirus.2
The cross-identification observed in CD4 + T cells led the researchers to the conclusion that COVID-19-based mRNA vaccines could be protective against SARS-CoV-2 variants. The efficacy of the COVID-19 vaccine against variants needs to be studied further to fully understand the level of protection.
- Woldemeskel, BA et al. (2021). SARS-CoV-2 mRNA vaccines induce broad-spectrum CD4 + T cell responses that recognize SARS-CoV-2 and HCoV-NL63 variants. The Journal of Clinical Investigation, In-Press Preview. Doi: 10.1172 / JCI149335.
- Dykema, AG et al. (2021). Activation of the CD4 + T-cell receptor is cross-reactive for SARS-CoV-2 and endemic coronaviruses. The Journal of Clinical Investigation, Pre-Press Preview. Doi: 10.1172 / JCI146922.
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