Neutralizing antibodies against SARS-CoV-2 variants of concern elicited by the comirnaty COVID-19 vaccine in nursing home residents

Abstract

Immunosenescence may impact the functionality and breadth of vaccine-elicited humoral immune responses. The ability of sera to neutralize the SARS-CoV-2 spike protein (S) from Beta, Gamma, Delta, and Epsilon variants of concern (VOCs) relative to the ancestral Wuhan-Hu-1 strain was compared in Comirnaty COVID-19-vaccinated elderly nursing home residents, either SARS-CoV-2 naïve (n = 22) or experienced (n = 8), or SARS-CoV-2 naïve younger individuals (n = 18) and non-vaccinated individuals who recovered from severe COVID-19 (n = 19). In all groups, except that including SARS-CoV-2-experienced nursing home residents, some participants lacked NtAb against one or more VOCs, mainly the Beta variant (15–20%). Serum NtAb titers were lowest against the Beta variant followed by Gamma, Delta and Epsilon variants. Overall, fold change reduction in NtAb titers relative to the ancestral strain was greatest for the Beta variant (6.7–19.4) followed by Gamma (4.8–16.0), Epsilon (2.9–13.4), and Delta (3.5–6.5) variants, although subtle differences were observed for Beta, Epsilon and Delta variants across comparison groups. In summary, older age, frailty, and concurrence of co-morbidities had no major impact on the serum NtAb activity profile against SARS-CoV-2 VOCs.

SARS‐CoV‐2 Omicron BA.1 variant breakthrough infections in nursing home residents after an homologous third dose of the Comirnaty® COVID‐19 vaccine: Looking for correlates of protection

“…Median predicted anti-RBD antibody levels for 2 days preinfection were comparable across groups (3445 BAU/ml; IQR, 80. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]713 vs. 4345 BAU/ml;IQR,618, respectively; p = 0.59; Figure 2B). Similarly, predicted NtAb against Omicron 2 days before diagnosis also did not differ between groups (188.5 reciprocal IC 50 ; IQR, 0-267 vs. 88.9; IQR, 0-903.6; p = 0.70; Figure 2C).…”

Immunogenicity following two doses of BBIBP-CorV vaccine and a third booster dose with viral vector and Mrna COVID-19 vaccines against delta and omicron variants in prime immunized adults with two doses of BBIBP-CorV vaccine

“…Previous studies found that neutralizing antibodies and anti-SARS-CoV-2 IgG titers are compatible. The level of total anti-RBD antibodies was strongly correlated with the neutralizing antibodies titers of SARS-CoV-2, especially against the ancestral strain [35,36]. This study showed that the titers of total RBD Ig and anti-RBD IgG are correlated with the neutralizing antibody titers against delta and omicron variants.…”

Evaluation of a novel fully automated and ELISA- based assays for detecting anti- SARS- CoV-2 neutralizing antibodies

“…Based on the data obtained from previous studies, signi cant reductions in neutralization against the VOCs compared to the ancestral Wuhan-Hu-1 strain were reported in sera from fully vaccinated individuals and recovered COVID-19 patients [40]. Moreover, after either Delta or Omicron breakthrough infections, limited variant-speci c cross-neutralizing immunity was observed, suggesting that these variants are less immunogenic than previous VOCs [41].…”