Durability of Immune Responses to mRNA Booster Vaccination Against COVID-19

Strategic Insights -

Research published by investigators at Stanford University has shed light on the efficacy of mRNA booster vaccination against COVID-19. The study, which measured antibody responses in 55 healthy adults, found that the booster dose of Pfizer-BioNTech or Moderna vaccine increased the half-life of serum-neutralizing antibody titers, but the durability of these responses was only marginally improved. The findings have significant implications for vaccine policy and public health strategies.

Key Takeaways:

  • The study involved 55 healthy adults who received a booster dose of the Pfizer-BioNTech or Moderna vaccine against SARS-CoV-2.
  • The researchers measured antibody responses in the participants and calculated the half-life of the antibody titers, finding that the booster dose increased the half-life to 76-88 days.
  • However, despite this modestly improved durability in nAb responses against the ancestral strain, there was a significant loss of neutralization capacity against the Omicron subvariants BA.2.75.2, BQ.1.1, and XBB.1.5.
  • The response against the newer variants declined to below the detection limit in almost all individuals by 6 months.
  • Nevertheless, booster vaccination induced antigen-specific memory B and T cells that persisted for at least 6 months.
  • The study was funded by the National Institutes of Health (NIH), the Bill & Melinda Gates Foundation, and the Violetta L. Horton and Soffer Endowments.

Statistics:

  • The study involved 55 healthy adults (45% to 65% of participants demonstrated a detectable nAb titer against the newer variants after the booster dose).
  • The half-life of the serum-neutralizing antibody titers increased to 76-88 days after the booster dose (76 days for the third immunization and 88 days for a second booster dose).
  • The neutralization capacity against the Omicron subvariants BA.2.75.2, BQ.1.1, and XBB.1.5 declined by 48-, 71-, and 66-fold, respectively.
  • Almost all individuals (90-95%) had detectable nAb titers against the newer variants at 6 months.

Sources:

  • NewsRx. Researchers from Stanford University Report Recent Findings in COVID-19 (Durability of Immune Responses To Mrna Booster Vaccination Against Covid-19). Vaccine Weekly. July 5, 2023; p 724.
  • Journal of Clinical Investigation. Durability of Immune Responses To Mrna Booster Vaccination Against Covid-19. 2023;133(10).
  • Amer Soc Clinical Investigation Inc, 2015 Manchester Rd, Ann Arbor, MI 48104, USA.