Intensive vaccination is recommended for populations more vulnerable to COVID-19 infection, although data regarding the built of immunity after vaccination for dialysis patients are lacking. This prospective, observational cohort study of maintenance hemodialysis patients examined IgG antibody levels against the SARS-CoV-2 spike (S1) protein, neutralizing activity, and interferon gamma levels after the third dose of the BNT162b2 (Pfizer–BioNTech) or mRNA-1273 (Moderna) vaccine. Humoral immunity was repeatedly measured for up to two months. The study includes 58 patients on hemodialysis. Median neutralizing antibodies reached a maximum at 12 and 9 days after booster vaccination with BNT162b2 and mRNA-1273, respectively. The median IgG antibody titer reached a maximum of 3943.16 and 5690.56 AU/mL after 28 and 21 days of booster dose, and cellular immunity was positive in 61.9% and 100% of patients with BNT162b2 and mRNA-1273 vaccination, respectively. By repeating the measurements over a period of two months, we clarified the chronological aspects of the acquisition of humoral immunity in dialysis patients after a booster COVID-19 vaccination; most dialysis patients acquired not only humoral immunity, but also cellular immunity against SARS-CoV-2. Future research should investigate the continued long-term dynamics of antibody titers and cellular immunity after the third or further vaccinations, evaluating the need for additional vaccinations for hemodialysis patients.

ObjectivesThis study aimed to identify factors that delayed emergency medical services (EMS) in evacuation order zones after the 2011 Great East Japan Earthquake and Fukushima Daiichi Nuclear Power Plant accident and to investigate how the lifting of the evacuation affected these factors over time.DesignThis research was a retrospective observational study. The primary outcome measure was onsite EMS time. A gradient boosting model and a decision tree were used to find the boundary values for factors that reduce EMS.SettingThe target area was Minamisoma City, Fukushima, Japan that was partly designated as an evacuation order zone after the 2011 Fukushima disaster, which was lifted due to decreased radiation.ParticipantsThis study included patients transferred by EMS from 1 January 2013 through 31 October 2018. Patients who were not transported and those transported for community events, interhospital patient transfer and natural disasters were excluded.Outcome measuresThis study evaluated the total EMS time using on-site time which is the time from arrival at the scene to departure to the destination, and other independent factors.ResultsThe total number of transports was 12 043. The decision tree revealed that the major factors that prolonged onsite time were time of day and latitude, except for differences by year. While latitude was a major factor in extending on-site time until 2016, the effect of latitude decreased and that of time of day became more significant since 2017. The boundary was located at N37.695° latitude.ConclusionsThe onsite time delay in EMS in evacuation order zones is largely due to regional factors from north to south and the time of day. However, the north-south regional factor decreased with the lifting of evacuation orders.