Influenza Vaccination in Systemic Lupus Erythematosus: Efficacy, Effectiveness, Safety, Utilization, and Barriers

Influenza increases morbidity and mortality in systemic lupus erythematosus (SLE) and lupus nephritis but is preventable through vaccination. This systematic review of PubMed, Embase, CENTRAL, WHO Clinical Trials, and ClinicalTrials.gov publications until August 2021 identified 45 reports (16,596 patients), including 8.5% with renal involvement or lupus nephritis: 9 studies (10,446 patients) on clinical effectiveness, 20 studies (1327 patients) on vaccine efficacy, 22 studies (1116 patients) on vaccine safety, 14 studies (4619 patients) on utilization rates, and 5 studies (3220 patients) on barriers. Pooled seroconversion rates ranged between 46% and 56%, while seroprotection rates ranged from 68% to 73% and were significantly associated with age and disease duration. Influenza infection was lower in vaccinated patients with systemic lupus erythematosus compared with unvaccinated patients. Disease activity scores did not change significantly after vaccination and reported flares were mild to moderate. Pooled current vaccination rate was 40.0% (95% confidence interval [CI]: 33.7%-46.5%) with significant heterogeneity and associated with the gross domestic product (P = .002) and disease duration (P = .001). Barriers to vaccination were the lack of doctor recommendation (57.4%) and concerns over the safety or efficacy of the vaccine (12.7%).