[PDF][PDF] Early T cell and binding antibody responses are associated with COVID-19 RNA vaccine efficacy onset

S Kalimuddin, CYL Tham, M Qui, R de Alwis, JXY Sim… - Med, 2021 - cell.com
S Kalimuddin, CYL Tham, M Qui, R de Alwis, JXY Sim, JME Lim, HC Tan, A Syenina
Med, 2021cell.com
Background RNA vaccines against coronavirus disease 2019 (COVID-19) have
demonstrated∼ 95% efficacy in phase III clinical trials. Although complete vaccination
consisted of 2 doses, the onset of protection for both licensed RNA vaccines was observed
as early as 12 days after a single dose. The adaptive immune response that coincides with
this onset of protection could represent the necessary elements of immunity against COVID-
19. Methods Serological and T cell analysis was performed in a cohort of 20 healthcare …
Background
RNA vaccines against coronavirus disease 2019 (COVID-19) have demonstrated ∼95% efficacy in phase III clinical trials. Although complete vaccination consisted of 2 doses, the onset of protection for both licensed RNA vaccines was observed as early as 12 days after a single dose. The adaptive immune response that coincides with this onset of protection could represent the necessary elements of immunity against COVID-19.
Methods
Serological and T cell analysis was performed in a cohort of 20 healthcare workers after receiving the first dose of the Pfizer/BioNTech BNT162b2 vaccine. The primary endpoint was the adaptive immune responses detectable at days 7 and 10 after dosing.
Findings
Spike-specific T cells and binding antibodies were detectable 10 days after the first dose of the vaccine, in contrast to receptor-blocking and severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) neutralizing antibodies, which were mostly undetectable at this early time point.
Conclusions
Our findings suggest that early T cell and binding antibody responses, rather than either receptor-blocking or virus neutralizing activity, induced early protection against COVID-19.
Funding
The study was funded by a generous donation from The Hour Glass to support COVID-19 research.
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