The BNT162b2 vaccine elicits robust lymph node T follicular helper cell responses

COVID-19 mRNA vaccines generate high concentrations of circulating anti-Spike antibodies and Spike-specific CD4+ T cells following prime-boost vaccination. It is not yet clear if vaccine-induced CD4+ T cell responses in the draining lymph node contribute to this outstanding immunogenicity. Using fine needle aspiration of draining axillary lymph nodes from individuals who received the BNT162b2 mRNA vaccine, we found large populations of Spike-specific CD4+ T follicular helper cells in the draining lymph node. A broadly immunodominant HLA-DPB1*04-restricted response to Spike166-180 composes one of the largest populations of T follicular helper cells in individuals with this allele, which is itself among the most common HLA alleles in the human population. Spike-specific T follicular helper cells are present in the lymph node 30 days after vaccine boost and persist in some individuals more than 170 days. Collectively, our results underscore the key role that robust T follicular helper cell responses play in the establishment of long-term immunity in this very efficacious human vaccine. Overall design: Bulk T cell receptor (TCR) sequences were obtained from the lymph nodes of four donors, each at two distinct time points after vaccination. The metadata.txt (representing 16 samples) contains each sample information and additional details required for demultiplexing.