American Diabetes Association
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Diabetes mellitus Affects Antibody Response to SARS-CoV-2 Vaccination in Older Residents of Long-Term Care Facilities: Data from the GeroCovid Vax Study

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Version 2 2022-10-10, 18:36
Version 1 2022-10-06, 19:22
posted on 2022-10-10, 18:36 authored by Enrico Virgilio, Caterina Trevisan, Angela Abbatecola, Alba Malara, Annapina Palmieri, Giorgio Fedele, Paola Stefanelli, Pasqualina Leone, Ilaria Schiavoni, Stefania Maggi, Stefano Volpato, Raffaele Antonelli Incalzi, Graziano Onder, the GeroCovid Vax working group



OBJECTIVE: Type 2 Diabetes mellitus may affect the humoral immune response following vaccinations, but data concerning COVID-19 vaccines are scarce. We evaluated the impact of diabetes mellitus on antibody response to the SARS-CoV-2 vaccination in older long-term care facilities (LTCF) residents and tested for differences according to anti-diabetic treatment.

RESEARCH DESIGN AND METHODS: 555 older LTCF residents participating in the GeroCovid Vax study were included for this analysis. SARS-CoV-2 trimeric S Immunoglobulin G (anti-S-IgG) concentrations using chemiluminescent assays were tested before the first dose and after 2- and 6-months. The impact of diabetes on anti-S-IgG levels was evaluated using linear mixed models, which included the interaction between time and the presence of diabetes. A second model considered also diabetes treatment: no insulin therapy (including dietary only or use of oral anti-diabetic agents) and insulin therapy (alone or in combination with oral anti-diabetic agents).

RESULTS: The sample's mean age was 82.1 years, 68.1% were women and 25.2% were diabetic. In linear mixed models, the presence of diabetes mellitus was associated with lower anti-S-IgG levels 2 (β=-0.20, 95%CI:-0.34,-0.06) and 6 months (β=-0.22, 95%CI:-0.37,-0.07) after the first vaccine dose. Compared to those without diabetes, diabetic residents not using insulin had lower IgG levels at 2- and 6-month assessments (β=-0.24, 95%CI:-0.43,-0.05, and β=-0.30, 95%CI:-0.50,-0.10, respectively), while no differences were observed for those under insulin. 

CONCLUSION: Older LTCF residents with diabetes tended to have weaker antibody response to COVID-19 vaccination. Insulin treatment might buffer this effect and establish a humoral immunity similar to non-diabetic individuals.


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