Humoral and Cellular Responses to COVID-19 Vaccination Indicate the Need for Post-Vaccination Testing in Frail Population

Wojciech Witkowski; Sarah Gerlo; Evelien De Smet; Magdalena Wejda; Delphine Acar; Steven Callens; Stefan Heytens; Elizaveta Padalko; Hanne Vercruysse; Piet Cools; Linos Vandekerckhove

doi:10.3390/vaccines10020260

Vaccines (Feb 2022)

Humoral and Cellular Responses to COVID-19 Vaccination Indicate the Need for Post-Vaccination Testing in Frail Population

Wojciech Witkowski,
Sarah Gerlo,
Evelien De Smet,
Magdalena Wejda,
Delphine Acar,
Steven Callens,
Stefan Heytens,
Elizaveta Padalko,
Hanne Vercruysse,
Piet Cools,
Linos Vandekerckhove

Affiliations

Wojciech Witkowski: HIV Cure Research Center, Department of Internal Medicine and Pediatrics, Ghent University Hospital, Ghent University, 9000 Ghent, Belgium
Sarah Gerlo: HIV Cure Research Center, Department of Internal Medicine and Pediatrics, Ghent University Hospital, Ghent University, 9000 Ghent, Belgium
Evelien De Smet: HIV Cure Research Center, Department of Internal Medicine and Pediatrics, Ghent University Hospital, Ghent University, 9000 Ghent, Belgium
Magdalena Wejda: HIV Cure Research Center, Department of Internal Medicine and Pediatrics, Ghent University Hospital, Ghent University, 9000 Ghent, Belgium
Delphine Acar: HIV Cure Research Center, Department of Internal Medicine and Pediatrics, Ghent University Hospital, Ghent University, 9000 Ghent, Belgium
Steven Callens: Department of Internal Medicine and Pediatrics, Ghent University Hospital, Ghent University, 9000 Ghent, Belgium
Stefan Heytens: Department of Public Health and Primary Care, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium
Elizaveta Padalko: Department of Diagnostic Sciences, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium
Hanne Vercruysse: Research and Analytics, Liantis Occupational Health Services, 8000 Bruges, Belgium
Piet Cools: Department of Diagnostic Sciences, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium
Linos Vandekerckhove: HIV Cure Research Center, Department of Internal Medicine and Pediatrics, Ghent University Hospital, Ghent University, 9000 Ghent, Belgium

DOI: https://doi.org/10.3390/vaccines10020260
Journal volume & issue: Vol. 10, no. 2
p. 260

Abstract

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Despite the high efficacy of the BNT162b2 vaccine in the general population, data on its immunogenicity among frail elderly individuals are limited. Recently, levels of anti-SARS-CoV-2 spike IgG antibodies and serum neutralization titers were confirmed as good immune markers of protection against the virus, with evidence showing a reverse correlation between these two parameters and susceptibility to infection. Here we analyzed sera from 138 nursing home residents (median age of 88.9 years) and 312 nursing home staff (median age of 50.7 years) to determine the humoral response to two doses of the BNT162b2 vaccine, and found markedly decreased serum anti-spike antibody levels and neutralization titers in the nursing home resident (NHR) group, with over 11% non-responders compared to only 1.3% among the controls. Moreover, three months post-vaccination, a significant decrease in antibody titers was observed in COVID-19-naive nursing home residents. Subsequent flow cytometry and interferon gamma secretion analyses indicated that antibody non-responders among NHRs also failed to mount cellular responses. The presented data emphasize that additional measures are needed in the population of frail elderly individuals. Given the high proportion of non-responders among NHRs, continued monitoring should be considered in this group.

Published in Vaccines

ISSN: 2076-393X (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Medicine
Website: http://www.mdpi.com/journal/vaccines

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Abstract

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