Ponente
Descripción
The production of antibodies in response to an infection or vaccination is an essential process to combat and prevent infectious diseases, being the binding of the antibody to the antigen a non-covalent interaction [1]. Avidity is defined as the binding strength between bivalent and multivalent interactions of the antigen to the antibody [2]. Current subunit-based anti-COVID vaccine formulations, such as Abdala or Mambisa, are designed to target the S protein of the wild-type (wt) virus, derived from the original Wuhan strain, and have been shown to offer a high degree of protection. Vaccination causes an increase in antibody avidity, suggesting potential antibody maturation after vaccination [3]. A strong positive correlation has been demonstrated between IgG titers and avidity and of these variables with viral neutralization in antibodies by vaccination [4]. The objective of the work was to develop a method for the evaluation of avidity in vaccinated individuals. An ELISA-type assay was modified, where the plates are coated with the RBD protein of the D614G (wt) or OMICRON (BA.5) variants. To analyze the avidity of the antibodies in the vaccinated, the elution principle was used as a methodology, which consisted of adding potassium thiocyanate (KSCN) as a chaotropic agent, after the formation of the antigen-antibody complex. Samples from convalescents who received a booster dose were analyzed. The samples of the vaccinated showed high avidity indices and the results obtained correlated with the antibody and neutralization titers.
