Diminished and waning immunity to COVID-19 vaccination among hemodialysis patients in Israel: the case for a third vaccine dose

Angel-Korman, Avital; Peres, Esther; Bryk, Gabriel; Lustig, Yaniv; Indenbaum, Victoria; Amit, Sharon; Rappoport, Vladimir; Katzir, Zeev; Yagil, Yoram; Iaina, Nomy Levin; Leiba, Adi; Brosh-Nissimov, Tal

BACKGROUND: Humoral responses to COVID-19 vaccines in hemodialysis patients can direct vaccination policy. METHODS: We compared 409 COVID-19 naïve hemodialysis patients from 13 hemodialysis units in Israel to 148 non-dialysis dependent COVID-19 naïve controls. Twenty-four previously infected (anti-nucleocapsid positive) hemodialysis patients were analyzed separately. Blood samples were obtained ≥ 14 days post vaccination (BNT162b2) to assess seroconversion-rates and titers of anti-S and neutralizing antibodies. RESULTS: Median time from vaccination to blood sample collection was 82 (IQR 64–87) and 89 (IQR 68–96) days, for hemodialysis patients and controls, respectively. Seroconversion rates were lower in hemodialysis patients compared to controls for both anti-S and neutralizing antibodies (89% and 77% vs. 99.3%, respectively, P < 0.0001). Antibody titers were also significantly lower in hemodialysis patients compared to controls: median 69.6 (IQR 33.2–120) vs. 196.5 (IQR 118.5–246), P < 0.0001; geometric mean titer 23.3 (95% CI 18.7–29.1) vs. 222.7 (95% CI 174–284), P < 0.0001, for anti-S and neutralizing antibodies, respectively. Multivariate analysis demonstrated dialysis dependence to be strongly associated with lower antibody responses and antibody titers waning with time. Age, low serum albumin and low lymphocyte count were also associated with lower seroconversion rates and antibody titers. Hemodialysis patients previously infected with SARS-COV-2 had no difference in their seroconversion rates or antibody titers compared to COVID-19 naïve patients. CONCLUSION: This study demonstrates diminished and waning humoral responses following COVID-19 vaccination in a large and diverse cohort of hemodialysis patients, including those previously infected with SARS-CoV-2. Considering these results and reduced vaccine effectiveness against variants of concern, in addition to continued social-distancing precautions, a third booster dose should be considered in this population.