Long-Term Immuno-Response and Risk of Breakthrough Infection After SARS-CoV-2 Vaccination in Kidney Transplantation

Area of Science:

• Immunology
• Transplantation
• Vaccinology

Background:

• Kidney transplant recipients (KTx) have diminished SARS-CoV-2 vaccine responses.
• Understanding immunity correlates and breakthrough infection risks is crucial.

Purpose of the Study:

• To evaluate humoral response trajectories after SARS-CoV-2 vaccination in KTx recipients.
• To identify risk factors for breakthrough SARS-CoV-2 infections in this population.

Main Methods:

• Longitudinal assessment of anti-spike antibody titers in 189 KTx recipients over 12 months.
• Analysis included patients with prior COVID-19 (DIS/INF) and infection-naïve (NEG) status.
• Linear mixed models and survival analyses were used to determine influencing factors.

Main Results:

• Antibody levels were higher in previously infected patients. Infection-naïve recipients showed increased seropositivity post-vaccination and booster, reaching 78% at 12 months.
• Age, BMI, antimetabolites, and steroids significantly impacted antibody titers.
• Breakthrough infections occurred in 31.9% of patients; mTOR inhibitors were associated with reduced risk.

Conclusions:

• Humoral response to SARS-CoV-2 vaccination is limited in infection-naïve KTx patients but improved by boosters and hybrid immunity.
• Immunosuppressive drug regimens critically influence vaccine response.
• mTOR inhibitors may offer protection against breakthrough SARS-CoV-2 infections in KTx recipients.