Análisis de la respuesta inmune a la vacuna de ARNm anti-SARS-CoV-2: Respuesta celular, humoral y subpoblaciones linfocitarias
Year: 2021
Type: dissertation
Study design: Observational Study
Abstract: Coronavirus 2019 (COVID-19) is a respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that has a wide variety of clinical manifestations, ranging from asymptomatic infection to respiratory failure and death. When it first emerged in the city of Wuhan, China, the COVID-19 disease spread rapidly to multiple countries, leading to the overload of healthcare systems worldwide. For this reason and for its high morbidity and mortality, COVID-19 was declared a pandemic by the World Health Organization on March of 2020. To gain control over the pandemic, numerous anti-SARS-CoV-2 vaccines have been developed, BNT162b2 being one of them. BNT162b2 is a mRNA vaccine formulated in lipid nanoparticles that encodes the complete sequence of the SARS-CoV-2 spike protein. In this study the immune response to the BNT162b2 vaccine was analyzed in a cohort of 75 healthcare workers from Hospital Universitario 12 de Octubre who received two 30 μg doses. With this purpose, peripheral blood samples were taken at different timepoints up to three months after vaccination. The specific cellular response was measured with an IFN-γ/IL-2 FluoroSpot, the specific humoral response with an anti-SARS-CoV-2 ELISA, and variations in lymphocyte subpopulations were studied by flow cytometry. Both BNT162b2 doses elicited a spike-specific cellular response that peaked on day 15 after the second dose with a median of 591 IFN-γ-secreting T cells/106 PBMCs followed by a gradual decrease until the end of the three month observation period, after which 73/75 (97%) of individuals maintained a positive cellular response. Additionally, it was observed that this response was higher in participants who had suffered a SARS-CoV-2 infection before being vaccinated. Furthermore, the vaccine induced an increase in anti-spike IgG levels in all participants with a peak also on day 15 after the administration of the second vaccine dose with a median anti-spike IgG level of 14.35. Afterwards, the humoral response stabilized in convalescent participants, while previously healthy individuals showed a declining COVID-19 response on the third month after vaccination, despite of which 100% of them maintained a positive specific humoral response. Flow cytometry analysis did not exhibit any important variations in lymphocyte subpopulations in relation to the vaccine. In summary, BNT162b2 evoked a robust cellular and humoral response against SARS-CoV-2 spike protein that remained positive three months after vaccination in almost all participants.
Source: Hispana
Author: Durán Renieblas, Marta
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7045314921