SARS-CoV-2 mRNA vaccine induced higher antibody affinity and IgG titers against variants of concern in post-partum vs non-post-partum women

EBioMedicine. 2022 Mar:77:103940. doi: 10.1016/j.ebiom.2022.103940. Epub 2022 Mar 14.

Abstract

Background: Limited knowledge exists in post-partum women regarding durability of SARS-CoV-2 vaccine-induced antibody responses and their neutralising ability against SARS-CoV-2 variants of concern (VOC).

Methods: We elucidated longitudinal mRNA vaccination-induced antibody profiles of 13 post-partum and 13 non-post-partum women (control).

Findings: The antibody neutralisation titres against SARS-CoV-2 WA-1 strain were comparable between post-partum and non-post-partum women and these levels were sustained up to four months post-second vaccination in both groups. However, neutralisation titers declined against several VOCs, including Beta and Delta. Higher antibody binding was observed against SARS-CoV-2 receptor-binding domain (RBD) mutants with key VOC amino acids when tested with post-second vaccination plasma from post-partum women compared with controls. Importantly, post-vaccination plasma antibody affinity against VOCs RBDs was significantly higher in post-partum women compared with controls.

Interpretation: This study demonstrates that there is a differential vaccination-induced immune responses in post-partum women compared with non-post-partum women, which could help inform future vaccination strategies for these groups.

Funding: The antibody characterisation work described in this manuscript was supported by FDA's Medical Countermeasures Initiative (MCMi) grant #OCET 2021-1565 to S.K and intramural FDA-CBER COVID-19 supplemental funds.

Keywords: Affinity maturation; COVID-19; Neutralisation; SARS-CoV-2; Spike; Vaccine.

MeSH terms

  • Antibodies, Viral
  • Antibody Affinity
  • COVID-19 Vaccines*
  • COVID-19* / prevention & control
  • Female
  • Humans
  • Immunoglobulin G
  • Postpartum Period
  • SARS-CoV-2 / genetics
  • Vaccines, Synthetic
  • mRNA Vaccines

Substances

  • Antibodies, Viral
  • COVID-19 Vaccines
  • Immunoglobulin G
  • Vaccines, Synthetic
  • mRNA Vaccines

Supplementary concepts

  • SARS-CoV-2 variants