Impaired Functional T-Cell Response to SARS-CoV-2 After Two Doses of BNT162b2 mRNA Vaccine in Older People

• Published in: Frontiers in immunology 2021-11, Vol.12, p.778679-778679
• Main Authors: Demaret, Julie, Corroyer-Simovic, Bénédicte, Alidjinou, Enagnon Kazali, Goffard, Anne, Trauet, Jacques, Miczek, Sophie, Vuotto, Fanny, Dendooven, Arnaud, Huvent-Grelle, Dominique, Podvin, Juliette, Dreuil, Daniel, Faure, Karine, Deplanque, Dominique, Bocket, Laurence, Duhamel, Alain, Labreuche, Julien, Sobaszek, Annie, Hisbergues, Michael, Puisieux, Francois, Labalette, Myriam, Lefèvre, Guillaume
• Format: Article
• Language: English
• Subjects: Adult; Aged, 80 and over; Antibodies, Neutralizing - immunology; Antibodies, Viral - immunology; BNT162 Vaccine - immunology; COVID-19 - immunology; COVID-19 - prevention & control; Female; Frailty - immunology; Humans; Immunogenicity, Vaccine; Immunology; Immunosenescence - immunology; Life Sciences; Male; Middle Aged; mRNA vaccination; Nutritional Status - immunology; older people and ageing; SARS – CoV – 2; SARS-CoV-2 - immunology; T cells response; T-Lymphocytes - immunology; vaccine
• ISSN: 1664-3224; 1664-3224
• DOI: 10.3389/fimmu.2021.778679

Long-term care facility (LTCF) older residents display physiological alterations of cellular and humoral immunity that affect vaccine responses. Preliminary reports suggested a low early postvaccination antibody response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The aim of this study was to focus on the specific T-cell response. We quantified S1-specific IgG, neutralizing antibody titers, total specific IFNγ-secreting T cells by ELISpot, and functionality of CD4 - and CD8 -specific T cells by flow cytometry, after two doses of the BNT162b2 vaccine in younger and older people, with and without previous COVID-19 infection (hereafter referred to as COVID-19-recovered and COVID-19-naive subjects, respectively). Frailty, nutritional, and immunosenescence parameters were collected at baseline in COVID-19-naive older people. We analyzed the immune response in 129 young adults (median age 44.0 years) and 105 older residents living in a LCTF (median age 86.5 years), 3 months after the first injection. Humoral and cellular memory responses were dramatically impaired in the COVID-19-naive older (  = 54) compared with the COVID-19-naive younger adults (  = 121). Notably, older participants' neutralizing antibodies were 10 times lower than the younger's antibody titers (