Humoral response after the fourth dose of the SARS-CoV-2 vaccine in the CKD spectrum: a prespecified analysis of the SENCOVAC study.

BACKGROUND: There is scarce evidence on the fourth dose of severe acute respiratory syndrome coronavirus 2 vaccines in chronic kidney disease (CKD) patients. We evaluated the humoral response and effectivity of the fourth dose in the CKD spectrum: non-dialysis CKD (ND-CKD), haemodialysis (HD), peritoneal dialysis (PD) and kidney transplant (KT) recipients. METHODS: This is a prespecified analysis of the prospective, observational, multicentric SENCOVAC study. In patients with CKD who had received a complete initial vaccination and one or two boosters and had anti-Spike antibody determinations 6 and 12 months after the initial vaccination, we analysed factors associated with persistent negative humoral response and higher anti-Spike antibody titres as well as the efficacy of vaccination on coronavirus disease 2019 (COVID-19) severity. RESULTS: Of 2186 patients (18% KT, 8% PD, 69% HD and 5% ND-CKD), 30% had received a fourth dose. The fourth dose increased anti-Spike antibody titres in HD (P = .001) and ND-CKD (P = .014) patients and seroconverted 72% of previously negative patients. Higher anti-Spike antibody titres at 12 months were independently associated with repeated exposure to antigen (fourth dose, previous breakthrough infections), previous anti-Spike antibody titres and not being a KT recipient. Breakthrough COVID-19 was registered in 137 (6%) patients, 5% of whom required admission. Admitted patients had prior titres <620 UI/ml and median values were lower (P = .020) than in non-admitted patients. CONCLUSIONS: A fourth vaccine dose increased anti-Spike antibody titres or seroconverted many CKD patients, but those with the highest need for a vaccine booster (i.e. those with lower pre-booster antibody titres or KT recipients) derived the least benefit in terms of antibody titres. Admission for breakthrough COVID-19 was associated with low anti-Spike antibody titres.

A multicentric survey of the practice of hand hygiene in haemodialysis units: factors affecting compliance.

BACKGROUND: This study intended to investigate the degree of compliance with hand hygiene and use of gloves by health workers in haemodialysis (HD) units, and the factors that influenced adherence to hand hygiene protocols. METHODS: During the month of November 2003, one person observed the health care staff in each of nine different dialysis units, during 495 randomly distributed 30 min observation periods that covered all steps of a haemodialysis session (connection, dialysis and disconnection). The observers noted the number of potential opportunities to implement standard precautions and the number of occasions on which the precautions were actually taken. Adherence to standard precautions was evaluated, analysing the influence of the following variables: the patient-to-nurse ratio, the number of HD shifts scheduled per day, acute HD units vs chronic, whether or not infectious patients were isolated and in-house vs contract cleaning personnel. RESULTS: There were a total of 977 opportunities to wear gloves for, and to wash the hands following, a patient-oriented activity, and 1902 opportunities to wash hands before such an activity. Gloves were actually used on 92.9% of these occasions. Hands were washed only 35.6% of the time after patient contact, and only 13.8% of the time before patient contact. Poor adherence to hand washing was associated with the number of shifts per HD unit per day and with higher patient-to-nurse ratios. In the acute HD units, there was greater adherence to standard precautions than in the chronic units, although there too it was substandard. The personnel's knowledge of patients' infectious status did not modify their adherence to hand hygiene practices. A higher patient-to-nurse ratio independently influenced hand washing both before and after patient contact. CONCLUSIONS: The overall adherence of health care workers to recommended hand washing practices is low. Whether or not programmes promoting higher hand hygiene standards and the potential use of alcohol-based hand cleansers will improve hand hygiene practices in HD units requires further investigation.