Immune responses during COVID-19 breakthrough cases in vaccinated children and adolescents.
Front Immunol
; 15: 1372193, 2024.
Article
en En
| MEDLINE
| ID: mdl-38812507
ABSTRACT
Background:
Vaccine effectiveness against SARS-CoV-2 infection has been somewhat limited due to the widespread dissemination of the Omicron variant, its subvariants, and the immune response dynamics of the naturally infected with the virus.Methods:
Twelve subjects between 3-17 years old (yo), vaccinated with two doses of CoronaVac®, were followed and diagnosed as breakthrough cases starting 14 days after receiving the second dose. Total IgGs against different SARS-CoV-2 proteins and the neutralizing capacity of these antibodies after infection were measured in plasma. The activation of CD4+ and CD8+ T cells was evaluated in peripheral blood mononuclear cells stimulated with peptides derived from the proteins from the wild-type (WT) virus and Omicron subvariants by flow cytometry, as well as different cytokines secretion by a Multiplex assay.Results:
2 to 8 weeks post-infection, compared to 4 weeks after 2nd dose of vaccine, there was a 146.5-fold increase in neutralizing antibody titers against Omicron and a 38.7-fold increase against WT SARS-CoV-2. Subjects showed an increase in total IgG levels against the S1, N, M, and NSP8 proteins of the WT virus. Activated CD4+ T cells showed a significant increase in response to the BA.2 subvariant (p<0.001). Finally, the secretion of IL-2 and IFN-γ cytokines showed a discreet decrease trend after infection in some subjects.Conclusion:
SARS-CoV-2 infection in the pediatric population vaccinated with an inactivated SARS-CoV-2 vaccine produced an increase in neutralizing antibodies against Omicron and increased specific IgG antibodies for different SARS-CoV-2 proteins. CD4+ T cell activation was also increased, suggesting a conserved cellular response against the Omicron subvariants, whereas Th1-type cytokine secretion tended to decrease. Clinical Trial Registration clinicaltrials.gov #NCT04992260.Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Linfocitos T CD4-Positivos
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Anticuerpos Neutralizantes
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Vacunas contra la COVID-19
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SARS-CoV-2
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COVID-19
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Anticuerpos Antivirales
Límite:
Adolescent
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Child
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Child, preschool
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Female
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Humans
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Male
Idioma:
En
Revista:
Front Immunol
Año:
2024
Tipo del documento:
Article
País de afiliación:
Chile
Pais de publicación:
Suiza