Strong Decay of SARS-CoV-2 Spike Antibodies after 2 BNT162b2 Vaccine Doses and High Antibody Response to a Third Dose in Nursing Home Residents.
J Am Med Dir Assoc
; 23(5): 750-753, 2022 05.
Article
en En
| MEDLINE
| ID: mdl-35311651
ABSTRACT
OBJECTIVES:
To measure the antibody decay after 2 BNT162b2 doses and the antibody response after a third vaccine dose administered 6 months after the second one in nursing home residents with and without prior COVID-19.DESIGN:
Cohort study. SETTING ANDPARTICIPANTS:
Four hundred-eighteen residents from 18 nursing homes.METHODS:
Blood receptor-binding domain (RBD)-IgG (IgG II Quant assay, Abbott Diagnostics; upper limit 5680 BAU) and nucleocapsid-IgG (Abbott Alinity) were measured 21â28 days after the second BNT162b2 dose, as well as 1â3 days before and 21â28 days after the third vaccine dose. RBD-IgG levels of ≥592 BAU/mL were considered as high antibody response. Residents with prior positive quantitative reverse transcription polymerase chain reaction on a nasopharyngeal swab or with N-IgG levels above 0.8 S/CO were considered as prior COVID-19 residents.RESULTS:
In prior COVID-19 residents (n = 122), RBD-IgG median levels decreased by 82% in 167 days on average. In the same period, the number of residents with a high antibody response decreased from 88.5% to 54.9% (P < .0001) and increased to 97.5% after the third vaccine dose (P = .02 vs the first measure). In residents without prior COVID-19 (n = 296), RBD-IgG median levels decreased by 89% in 171 days on average. The number of residents with a high antibody response decreased from 29.4% to 1.7% (P < .0001) and increased to 88.4% after the third vaccine dose (P < .0001 vs the first measure). CONCLUSIONS AND IMPLICATIONS The strong and rapid decay of RBD-IgG levels after the second BNT162b2 dose in all residents and the high antibody response after the third dose validate the recommendation of a third vaccine dose in residents less than 6 months after the second dose, prioritizing residents without prior COVID-19. The slope of RBD-IgG decay after the third BNT162b2 dose and the protection level against SARS-CoV-2 B.1.1.529 (omicron) and other variants of concern provided by the high post-boost vaccination RBD-IgG response require further investigation in residents.Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Vacunas
/
COVID-19
Tipo de estudio:
Etiology_studies
/
Guideline
/
Incidence_studies
/
Observational_studies
/
Risk_factors_studies
Límite:
Humans
Idioma:
En
Revista:
J Am Med Dir Assoc
Asunto de la revista:
HISTORIA DA MEDICINA
/
MEDICINA
Año:
2022
Tipo del documento:
Article