Original Research Article
Evaluation of T and B cell immunophenotyping and antibody response post Covid-19 vaccination

https://doi.org/10.1016/j.ijmmb.2023.100372Get rights and content

Highlights

  • Highly significant improvement in SARS-CoV-2 IgG levels were observed at 6 months post COVID-19 vaccination.

  • At 6 months post COVID-19 vaccination, mean values for CD4 & CD8 central memory and CD8 effector memory showed significant decrease; this patient subgroup would benefit most from booster dose which may offer protection.

  • Few subjects were identified where IgG levels returned to normal or reduced at 6 months compared to baseline, while there was increase in memory T cells, suggesting that this subgroup may not require additional booster dose of vaccination.

Abstract

Purpose

To evaluate T and B cell subsets and IgG antibodies in response to SARS-CoV-2 post COVID-19 vaccination.

Methods

A total of 50 healthy adults (18–60 years) receiving anti-SARS-CoV-2 vaccination (COVISHIELD) were recruited for the study. Blood samples were collected from participants at 3 time points; just before vaccination (Visit 0, V0), just before booster dose (Visit 1, V1) and 6th month after 1st dose (Visit 2, V2). Peripheral blood mononuclear cell isolation was done and evaluated for T and B cell subsets by Flow cytometry. Quantitative determination of IgG antibodies to SARS-CoV-2 was done by Chemiluminescence immunoassay in all samples. Final data for all three visits was available for 37 participants who remained healthy.

Ethics approval was obtained from Medanta Institution of Ethics Committee vide MICR No. 1290/2021 dated 24th May 2021.

Results

Mean age of the participants was 34.6 ​± ​5.7 years (Range: 24–45 years). Highly significant improvement in SARS-CoV-2 IgG levels was observed after each visit {Mean IgG: (V0 v/s. V1: 133.8 ​± ​339.2AU/ml v/s. 434.5 ​± ​519.2AU/ml; p-value ​= ​0.003) and V0 v/s. V2: 133.8 ​± ​339.2AU/ml v/s. 420.9 ​± ​394.2AU/ml; p-value ​= ​0.002) Between visits 0 and 1, the mean value for CD4 Naïve T cells showed significant increase, while CD4 central memory (CM) T cells showed significant decrease. Between visits 0 and 2 the mean values for CD4 Naïve T cells, CD8 Naïve T cells and Pre germinal centre (Pre GC) B cells showed significant increase. During the same period the mean values for CD4CM, CD8 effector memory (EM) and CD8 CM T cells showed significant decrease.

Conclusion

It is concluded that both, humoral and cellular immunity, play an important role in maintaining immunity against COVID-19 infection, following COVISHIELD vaccination. Moreover, in subjects with normalisation of antibody levels post vaccination, persistence of T cell subsets may still offer some immunity.

Keywords

T and B cell Immunophenotyping
COVID-19 vaccination
SARS-CoV-2 antibody response

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