Effectiveness of primary series, first, and second booster vaccination of monovalent mRNA COVID-19 vaccines against symptomatic SARS-CoV-2 infections and severe diseases during the SARS-CoV-2 omicron BA.5 epidemic in Japan: vaccine effectiveness real-time surveillance for SARS-CoV-2 (VERSUS).

BACKGROUND: This study aimed to evaluate VE of primary, first, and second booster ancestral-strain monovalent mRNA COVID-19 vaccination against symptomatic infections and severe diseases in Japan. METHODS: We conducted a test-negative case-control study. We included medically attended episodes and hospitalizations involving individuals aged ≥16 with signs and symptoms from July to November 2022, when Omicron BA.5 was dominant nationwide. To evaluate VE, we calculated adjusted ORs of vaccination among test-positive versus test-negative individuals using a mixed-effects logistic regression. RESULTS: For VE against symptomatic infections among individuals aged 16 to 59, VE of primary vaccination at > 180 days was 26.1% (95% CI: 10.6-38.8%); VE of the first booster was 58.5% (48.4-66.7%) at ≤90 days, decreasing to 41.1% (29.5-50.8%) at 91 to 180 days. For individuals aged ≥60, VE of the first booster was 42.8% (1.7-66.7%) at ≤90 days, dropping to 15.4% (-25.9-43.2%) at 91 to 180 days, and then increasing to 44.0% (16.4-62.5%) after the second booster. For VE against severe diseases, VE of the first and second booster was 77.3% (61.2-86.7%) at ≤90 days and 55.9% (23.4-74.6%) afterward. CONCLUSION: mRNA booster vaccination provided moderate protection against symptomatic infections and high-level protection against severe diseases during the BA.5 epidemic in Japan.

Efficacy of series double continuous hemodiafiltration using two polymethyl methacrylate membrane hemofilters for patients with hypercytokinemia.

Continuous hemodiafiltration using a hemofilter made from a membrane with cytokine adsorption properties is thought to be effective to remove cytokines in septic patients. In order to enhance cytokine removal capacity by increasing adsorption area, we devised a double polymethyl methacrylate continuous hemodiafiltration method, which involves serial connection of two polymethyl methacrylate membrane hemofilters, and we report clinical efficacy with this method. Of 74 patients who underwent continuous hemodiafiltration and had interleukin-6 blood levels measured during their ICU stay between March 2010 and June 2012, 13 patients with hypercytokinemia (interleukin-6 blood level >900 pg/mL) underwent series double continuous hemodiafiltration to be treated for hypercytokinemia. Cytokine reduction rate and clinical efficacy were compared between those 13 patients and those with a similar pathological condition who underwent continuous hemodiafiltration using the single polymethyl methacrylate membrane hemofilter. Interleukin-6 blood levels 6 h after continuous hemodiafiltration initiation increased in the single continuous hemodiafiltration group from 17040 ± 33660 pg/mL to 26290 ± 66250 pg/mL; however, interleukin-6 blood level significantly decreased in the series double continuous hemodiafiltration group from 20220 ± 29120 pg/mL to 6790 ± 10820 pg/mL. Interleukin-6 reduction rate during the period between initiation and 6 h after initiation of continuous hemodiafiltration was significantly higher in the series double continuous hemodiafiltration group(63.5 ± 38.9%) compared to that of the single continuous hemodiafiltration group (-342 ± 1306%)(P = 0.039). Series double continuous hemodiafiltration using two polymethyl methacrylate hemofilters with cytokine adsorbing capacity is effective to remove cytokine in hypercytokinemic septic patients.