SARS-CoV-2 specific T cells induced by both SARS-CoV-2 infection and mRNA vaccination broadly cross-recognize omicron

Abstract

The SARS-CoV-2 variant of concern (VOC) omicron (B1.1.529) is associated with high infectivity and efficient evasion from humoral immunity induced by previous infection or vaccination. In omicron-infected individuals who have been vaccinated or infected before, severe disease seems to be relatively infrequent pointing towards protection by previously primed SARS-CoV-2-specific T cells that cross-recognize omicron. By performing a comprehensive in-depth comparison of the SARS-CoV-2-specific T cell epitope repertoire after natural infection versus after mRNA vaccination, we here demonstrate that spike-derived epitopes are not dominantly targeted in convalescents compared to non-spike epitopes. In vaccinees, however, we detected a broader spike-specific T cell response compared to convalescents reflected by a more diverse repertoire of dominantly targeted spike-specific T cell epitopes. Booster mRNA vaccination induced a broader spike-specific T cell response in convalescents but not in vaccinees with complete initial vaccination. In convalescents and vaccinees, the targeted T cell epitopes are broadly conserved between ancestral and omicron SARS-CoV-2 variants. Hence, our data emphasize the relevance of mRNA vaccine-induced spike-specific CD8+ T cell responses in combating emerging SARS-CoV-2 VOC including omicron and support the benefit of also boosting convalescent individuals with mRNA vaccines.

Turning point: A new global COVID‐19 wave or a signal of the beginning of the end of the global COVID‐19 pandemic?

“…Additionally, the existing vaccine booster jab protects against symptomatic or asymptomatic infection, transmission, and severe infection by promoting specific CD8+ or CD4+ T‐cell response. It also neutralizes memory B‐cell receptor (BCR) width and weak respiratory mucosal neutralizing Ab responses 42,49–52 . Given these facts, some countries have been quick to respond.…”

“…It also neutralizes memory B‐cell receptor (BCR) width and weak respiratory mucosal neutralizing Ab responses. 42 , 49 , 50 , 51 , 52 Given these facts, some countries have been quick to respond. Among them, the United States continues to push the current program of two vaccine doses plus booster shots, which can enhance Omicron neutralization, especially in vulnerable groups such as the elderly, pregnant women, and immunocompromised populations.…”

Successive Site Translocating Inoculation Improved T Cell Responses Elicited by a DNA Vaccine Encoding SARS-CoV-2 S Protein

“…The contribution of cellular immune response to vaccine-induced protection against COVID-19 has been intensively discussed ( 23 , 24 ). Its potential to confer cross-protection against different SARS-CoV-2 variants is demonstrated by a few most recent studies ( 25 – 27 ). As a promising nucleic vaccine platform, DNA vaccine has unique advantages such as the low cost and extraordinary stability ( 28 ).…”