Humoral Response to BNT162b2 Vaccine Against SARS-CoV-2 Variants Decays After Six Months
Fecha
2022-05-02
Autores
Hernandez, Juan Carlos
Lopera, Tulio J.
Chvatal-Medina, Mateo
Flórez-Álvarez, Lizdany
Zapata-Cardona, Maria I.
Taborda, Natalia A.
Rugeles, Maria T.
Hernandez, Juan C.
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Universidad Cooperativa de Colombia, Facultad de Ciencias de la Salud, Programa de Medicina, Medellín y Envigado, Colombia, 00000
Resumen
SARS-CoV-2 vaccines have shown very high effectiveness in real-world scenarios.
However, there is compelling evidence for a fast-paced waning of immunity. The
increasing number of new variants that could alter the severity, transmissibility, and
potential to evade the immune response raised significant concern. Therefore, elucidating
changes in the humoral immune response against viral variants induced by vaccines over
time is crucial for improving immunization protocols. We carried out a 6-month longitudinal
prospective study in which 60 individuals between 21 and 71 years of age who have
received the complete scheme of the BNT162b2 vaccine were followed to determine titers
of serum neutralizing activity. The neutralizing capacity was measured at one, three, and
six-months post-vaccination by plaque reduction neutralization assay using SARS-CoV-2
B.1 (D614G) and the Gamma, Alpha, Delta, and Mu variants. Data were analyzed using
GraphPad 5.0. Neutralizing activity against five different SARS-CoV-2 variants was
detected in the serum samples of all vaccinated participants to a different extent after
one month, with a progressive decrease according to age and gender. Overall, after one
month of vaccination, the neutralizing titer was lower for all evaluated variants when
compared to B.1, most remarkable against Delta and Mu, with a reduction of 83.1% and
92.3%, respectively. In addition, the Titer at 3- or 6-months follow-up decreased
dramatically for all variants. Our results support the decaying of serum neutralizing
activity, both over time and across SARS-CoV-2 variants, being more significant in
older men. Since Delta and Mu appear to evade the neutralizing activity, these and
further new variants of immune escape mutations should be considered for novel
vaccine formulations.
Palabras clave
SARS-CoV-2 , vaccine , neutralizing antibodies , immunity , immunogenicity , variant