BNT162b2 Vaccination Elicits Strong Serological Immune Responses Against SARS-CoV-2 Including Variants of Concern in Elderly Convalescents

Abstract

Elderly residents of long-term care facilities (LTCFs) have long been underrepresented in studies on vaccine efficacy, particularly in light of currently emerging variants of concern (VOCs). In this prospective observational cohort study, we analyzed serological immune responses in 190 individuals before, 3 weeks after 1st and 3 weeks after 2nd vaccination with BNT162b2. Unvaccinated COVID-19-convalescent subjects served as reference. End points comprised serum anti-spike IgG and IgA titers as well as neutralization capacities against unmutated and mutated SARS-CoV-2 receptor binding domains including B.1.1.7, B.1.351 and P.1. We found that antibody titers and neutralization capacities up to 3 weeks after 2nd vaccination with BNT162b2 were significantly higher in COVID-19-convalescent as compared to COVID-19-naive vaccinees. Moreover, pre-vaccination anti-NCP IgG titers, but not age or gender, had a high impact on the strength and kinetics of post-vaccination neutralization capacity development. Most importantly, BNT162b2-induced neutralization capacity was cross-reactive with VOCs. In contrast to unvaccinated convalescents, vaccinated convalescent individuals of all ages acquired strong neutralizing capacities against current VOCs. The present study suggests that COVID-19-convalescent individuals with a broad age range between 18 and 98 years benefit from BNT162b2 vaccination by developing strong and broad neutralizing immune responses against SARS-CoV-2 including current VOCs.

Antibody response and intra-host viral evolution after plasma therapy in COVID-19 patients pre-exposed or not to B-cell depleting agents

“…Yet, this observation emphasizes the need for long-term surveillance for the emergence of new variants carrying mutations favoring escape to current population immunity by regular SARS-CoV-2 viral load and genomic monitoring. Finally, given the importance of the humoral immune response for clinical recovery (11), plasma therapy from convalescent vaccine-boosted donors remains a rational option, since it is unexpensive and logistically easy to organize, and contains high titers of neutralizing antibodies against SARS-CoV-2 associated to a broad antigenic spectrum (61-63).…”

“…In line with these observations, escape from polyclonal plasmas likely involves larger antigenic structural changes than escape from monoclonal Abs, targeting single epitopes (54). As comparable viral evolution patterns were given the importance of the humoral immune response for clinical recovery (11), plasma therapy from convalescent vaccine-boosted donors remains a rational option, since it is unexpensive and logistically easy to organize, and contains high titers of neutralizing antibodies against SARS-CoV-2 associated to a broad antigenic spectrum (61)(62)(63).…”

“…Collectively, our data show that vaccine-based plasma may represent an alternative treatment alongside to convalescent plasma, in the management of COVID-19 patients with B-cell lymphopenia. Besides, the use of plasma from vaccine-boosted convalescent individuals or from vaccinated ones boosted by a breakthrough infection likely broadens the spectrum of anti-SARS-CoV-2 humoral response, especially against variants such as Omicron to which convalescent-or vaccinated-only donors have not been exposed (61)(62)(63) and is currently the only source of plasma.…”

BNT162b2 Booster Vaccination Elicits Cross-Reactive Immunity Against SARS-CoV-2 Variants B.1.1.529 and B.1.617.2 in Convalescents of All Ages

“…Efficient vaccination of this population is thus not only in the personal interest of each elderly individual him- or herself, but also in the public interest, since the risk for the evolution of potentially hazardous viral mutations in each individual may be lower, if infections with SARS-CoV-2 are overcome as rapid as possible. This is particularly true in long-term care facilities (LTCFs) with their increased risk for outbrakes ( 5 , 6 ) and involvement of younger health care workers, who can easily spread viruses with newly accumulated, potentially hazardous mutations. Several studies confirmed the anticipated effectiveness of COVID-19 vaccines among elderly individuals over 60 years of age ( 6 – 11 ).…”

“…This is particularly true in long-term care facilities (LTCFs) with their increased risk for outbrakes ( 5 , 6 ) and involvement of younger health care workers, who can easily spread viruses with newly accumulated, potentially hazardous mutations. Several studies confirmed the anticipated effectiveness of COVID-19 vaccines among elderly individuals over 60 years of age ( 6 – 11 ). Currently, a particular focus lies on the Omicron variant (B.1.1.529), which was first identified in November 2021 in South Africa and Botswana, and which hosts a so far unprecedented number of mutations, resulting in extensive immune escape and reduced vaccine effectiveness ( 12 ).…”