Spike and neutralizing antibodies response to COVID-19 vaccination in hemodialysis patients

Giot, Matthieu; Fourié, Toscane; Lano, Guillaume; Villarroel, Paola Mariela Saba; de Lamballeri, Xavier; Gully, Marion; Samson, Laurent; Farault, Julien; Bouchouareb, Dammar; Jehel, Océane; Brunet, Philippe; Jourde-Chiche, Noémie; Ninove, Laetitia; Robert, Thomas

BACKGROUND: Humoral response to the SARS-COV-2 vaccines needs to be evaluated in the fragile population of patients on maintenance hemodialysis. METHODS: We analyzed the antibody response to the spike (S) antigen of SARS-CoV-2 before and after each dose of the mRNA Comirnaty Vaccine (BNT162b2; BioNTech & Pfizer) in patients from a single dialysis center, and detected the presence of neutralizing antibodies. RESULTS: Among the 90 vaccinated HD patients (mean age 69 years, 61% male), 19 (21%) had a history of SARS-CoV-2 infection. A seroconversion with anti-S IgG antibodies (Sab) was documented in 20% of patients after the first dose (early responders) and in 77% after the second dose, while 23% were non-responders. Cardiac disease, cirrhosis and gamma-globulin levels were independently predictive of the absence of seroconversion. Neutralizing antibodies (Nab) were detected in 15% of early responders after the first dose, and in 90% of early responders and 58% of late responders after the second dose. Sab titers after the second dose were higher in patients with Nab than without Nab (598 [IQR, 246-882] versus 134 [IQR, 61-390], p < 0.0001). All patients with a history of SARS-CoV-2 infection developed both Sab and Nab, and their titers of Sab and Nab were higher than in late responders CONCLUSIONS: Most HD patients develop a substantial humoral response against SARS-COV2, with neutralizing antibodies, following the mRNA vaccine. Whether this immunity persists over time, and is able to efficiently protect patients from COVID-19, remains to be determined.