B lymphocyte activation Aging 1 Animals 1 Antibodies 1 Antibodies, Viral 1 B-Lymphocytes 1 CD3 antigen 1 CD4 antigen 1 CD4+ CD25+ T lymphocyte 1 CD4+ T lymphocyte 1 CD8 antigen 1 CD8+ T lymphocyte 1 COVID-19 1 Cassia 1 Cassia auriculata 1 Cell Proliferation 1 Durability 1 Escherichia coli 1 Female 1 Flowers 1 Germinal center 1 Humans 1 IgA 1 IgG 1 IgM 1 Immunoglobulin A 1 Immunoglobulin G 1 Immunoglobulin M 1 Immunologic Factors 1 Immunosenescence 1