Although accumulating data have investigated the effect of SARS-CoV-2 mutations on antibody neutralizing activity, less is known about T cell immunity. In this work, we found that the ancestral (Wuhan strain) Spike protein can efficaciously reactivate CD4+ T cell memory in subjects with previous Alpha variant infection. This finding has practical implications, as in many countries only one vaccine dose is currently administered to individuals with previous COVID-19, independently of which SARS-CoV-2 variant was responsible of the infection. We also found that only a minority of Spike-specific CD4+ T cells targets regions mutated in Alpha, Beta and Delta variants, both after natural infection and vaccination. Finally, we found that the vast majority of Spike-specific CD4+ T cell memory response induced by natural infection or mRNA vaccination is conserved also against Omicron variant. This is of importance, as this newly emerged strain is responsible for a sudden rise in COVID-19 cases worldwide due to its increased transmissibility and ability to evade antibody neutralization. Collectively, these observations suggest that most of the memory CD4+ T cell response is conserved against SARS-CoV-2 variants of concern, providing an efficacious line of defense that can protect from the development of severe forms of COVID-19.
【저자키워드】 SARS-CoV-2, vaccination, T cells, CD4, cellular immunity, natural infection, variants of concern (VOCs), 【초록키워드】 COVID-19, mRNA vaccination, Immunity, spike, antibody, T cells, variant, SARS-CoV-2 variant, Infection, Delta, omicron, variants, Spike protein, memory, vaccine dose, Protein, Neutralizing activity, T cell, Region, Transmissibility, Alpha, target, Beta, Alpha variant, SARS-CoV-2 mutation, natural infection, T cell response, CD4+ T cell, Antibody neutralization, Delta variants, memory response, COVID-19 cases, observation, Implications, subject, COVID-19 case, individual, Wuhan strain, Defense, Administered, country, PROTECT, responsible, conserved, investigated, form, majority, less, mutated, evade, accumulating, 【제목키워드】 omicron, response, concern, CD4+, Against, Including,