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Vaccines

Double-Dose Vaccination Elicits Robust Antibody Responses in Older LTCF Residents

Strategic Insights

— 1 min read

A new prospective cohort study in England, known as VIVALDI, has shed light on the effectiveness of double-dose vaccination in older Long-Term Care Facility (LTCF) residents, particularly in relation to their immune responses to SARS-CoV-2. The study, which has not been peer-reviewed, involved 402 residents with a median age of 86 years and 632 staff members, with a total of 1317 blood samples collected 280 days after the second vaccination dose. The researchers found that peak antibody titers were 7.9-fold higher after Pfizer-BioNTech vaccination compared to Oxford-AstraZeneca, but also noted that antibody levels fell more rapidly compared to Oxford-AstraZeneca recipients.

Key Takeaways:

  • The study found that double-dose vaccination elicited robust and stable antibody responses in older LTCF residents, suggesting comparable levels of vaccine-induced immunity to that in the general population.
  • Peak antibody titers were 7.9-fold higher after Pfizer-BioNTech vaccination compared to Oxford-AstraZeneca (95% CI 3.6-17.0; P < 0.001).
  • Prior infection in both groups enhanced antibody levels.
  • Antibody levels were higher after Pfizer-BioNTech vaccination but fell more rapidly compared to Oxford-AstraZeneca recipients.
  • The study involved 402 LTCF residents with a median age of 86 years and 632 staff members.
  • The researchers measured quantitative titres of SARS-CoV-2 anti-spike antibodies in residents and staff following second vaccination dose.
  • The study used linear mixed effects models to investigate differences in peak antibody levels and rates of decline.

Statistics:

  • Peak antibody titers were 7.9-fold higher after Pfizer-BioNTech vaccination compared to Oxford-AstaZeneca.
  • Prior infection enhanced antibody levels in both groups.
  • 402 LTCF residents with a median age of 86 years participated in the study.
  • 632 staff members participated in the study.
  • 1317 blood samples were collected from residents and staff.
  • The study followed participants for 280 days after the second vaccination dose.

Sources:

  • medrxiv.org/content/10.1101/2022.01.26.22269885v1

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