Abstract
Background: The efficacy of COVID-19 vaccines to generate immunological memory post-vaccination has not previously been studied.
Objective: To assess immunological memory in previously SARS-CoV-2 infected individuals after a single dose of mRNA vaccine.
Patients and methods: Healthcare workers (n = 280) were enrolled after obtaining written informed consent and grouped under previously infected and no prior exposure (reverse transcription-polymerase chain reaction positive and negative, respectively). Blood was drawn at baseline and post-vaccination (single dose of COVISHIELD) for enumerating neutralizing antibodies by chemiluminescence and memory T- and B-cells by flow cytometry.
Results: Post vaccination, compared with the no prior exposure group, the previously infected group had higher levels of: antibody response (1124.73 ± 869.13 vs 94.23 ± 140.06 AU/ml, p = 0.0001); CD4 memory T-cells: central memory CCR7+CD45RA- (p = 0.0001), effector memory CCR7-/CD45RA- (p = 0.01); total CD8+ T-cells (p = 0.004); CD8+ naïve T-cells CCR7+CD45RA+ (p = 0.01); and memory B-cells CD20+CD27+ (p = 0.0001).
Discussion: Single-dose vaccination elicited higher neutralizing antibody response and protective immunity in individuals who had recovered from SARS-CoV-2 infection compared with those with no prior exposure.
Keywords: COVID-19; Memory B-cells; Memory T-cells; SARS-CoV-2.
【저자키워드】 COVID-19, SARS-CoV-2, Memory B-cells, Memory T-cells, 【초록키워드】 neutralizing antibody, SARS-CoV-2, Efficacy, COVID-19 vaccine, vaccination, mRNA vaccine, SARS-COV-2 infection, Antibody Response, CD4, Immunological memory, healthcare worker, flow cytometry, memory, protective immunity, T-cell, chemiluminescence, Neutralizing antibody response, single dose, B-cell, Single-dose, memory B-cell, individual, naïve, positive, CD8+, memory T, effector memory, enrolled, generate, elicited, baseline, CD8+ T-cell, central memory, exposure group, SARS-CoV-2 infected individual, 【제목키워드】 COVID-19 vaccine, memory, Neutralizing activity, single dose, infected individual,