Long-term Care, Immunity, and Frailty in Elderly COVID-19 [LIFE-CO, study data contributed to the CITF Databank]

The study aimed to examine immune responses over time, the role of frailty and co-infections, and the extent to which immune responses after vaccination relate to severe illness or reinfection.

Methods

This cohort study recruited residents from long-term care facilities in Nova Scotia who were then categorized as COVID-19 exposed uninfected, COVID-19 recovered, or COVID-19 unexposed. Participants provided blood samples via venipuncture for plasma-based anti-SARS-CoV-2 spike serology and fingerstick for dried blood spot serology, at baseline and during five follow-ups: pre-boost (2–4 weeks post-first vaccine dose), and at 1-, 3-, 6-, and 12-months post-boost.

Immune responses were analyzed to compare humoral and cell-mediated immunity, assess the impact of frailty and co-infections (e.g., CMV), and evaluate associations between vaccine-induced protection against severe illness or reinfection. Contributed Dataset Contents: The dataset includes 405 participants with baseline visits between April 2020 and December 2021. 85% of participants gave one or more blood samples between December 2020 and August 2022 for analysis.

A total of 1765 samples were collected. Variables include data in the following areas of information: demographics (age, sex, indigeneity), general health (weight and height, tobacco use, chronic conditions, immunosuppressants, flu vaccines), COVID-19 infection (rapid antigen or PCR test results, symptoms, hospitalizations, treatments), SARS-CoV-2 vaccination, and hematology.