Post vaccination acute kidney injury and other renal complications after COVID-19 and influenza vaccination.

backgroundVaccination remains a cornerstone of public health, yet concerns regarding serious adverse events continue to contribute to vaccine hesitancy. While systemic and local vaccine reactions are well described, renal complications such as acute kidney injury (AKI) and immune-mediated glomerular disease are less well characterised. With widespread and sustained use of coronavirus disease 2019 (COVID-19) and influenza vaccines, a comprehensive synthesis of reported renal adverse outcomes is needed.

aimTo synthesise and critically evaluate the existing evidence on AKI and other renal manifestations reported following influenza and COVID-19 vaccination. Specifically, it aims to characterise the spectrum of reported renal presentations, summarise clinical features and timelines described in case reports and case series, and contextualise these findings using population-level observational and pharmacovigilance data to assess the overall renal safety profile of these vaccines.

methodsWe conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. PubMed and EMBASE were searched from inception to 6 December 2025 for studies reporting renal outcomes following COVID-19 or influenza vaccination. Eligible studies included observational studies, pharmacovigilance analyses, case reports, and case series. Data on incidence, clinical presentation, timing of onset, management, and outcomes were extracted and synthesised narratively due to heterogeneity. Risk of bias in observational studies was assessed using the Risk Of Bias In Non-randomised Studies - of Interventions (ROBINS-I) tool.

resultsA total of 255 COVID-19 vaccine-related studies and 73 influenza vaccine-related studies met the inclusion criteria, supplemented by additional studies identified through reference screening. Population-level observational studies consistently demonstrated a low absolute risk of renal adverse outcomes following vaccination, with several studies reporting reduced AKI-related risk among vaccinated individuals. In contrast, pharmacovigilance analyses and case reports described serious instances of de novo or relapsing renal disease, including minimal change disease, immunoglobulin A nephropathy, membranous nephropathy, pauci-immune glomerulonephritis, and systemic inflammatory syndromes with secondary renal involvement. Symptom onset typically occurred within days to weeks of vaccination. Most cases responded favourably to supportive or disease-specific therapy, with recovery observed over weeks to months; irreversible renal outcomes were uncommon.

conclusionCurrent evidence indicates that both COVID-19 and influenza vaccines are associated with a low population-level risk of adverse renal outcomes. Serious immune-mediated renal events have been reported in temporal association with vaccination, likely reflecting idiosyncratic immune responses or unmasking of pre-existing disease rather than a widespread nephrotoxic effect. The overall benefits of vaccination substantially outweigh potential renal risks. Ongoing surveillance and well-designed population-based studies remain essential to refine risk estimates and identify susceptible subgroups.