Effectiveness of Messenger RNA Coronavirus Disease 2019 Vaccines Against Symptomatic Severe Acute Respiratory Syndrome Coronavirus 2 Infections During the Delta Variant Epidemic in Japan: Vaccine Effectiveness Real-time Surveillance for SARS-CoV-2 (VERSUS).

BACKGROUND: Although high vaccine effectiveness of messenger RNA (mRNA) coronavirus disease 2019 (COVID-19) vaccines has been reported in studies in several countries, data are limited from Asian countries, especially against the Delta (B.1.617.2) variant. METHODS: We conducted a multicenter test-negative case-control study in patients aged ≥16 years visiting hospitals or clinics with signs or symptoms consistent with COVID-19 from 1 July to 30 September 2021, when the Delta variant was dominant (≥90% of SARS-CoV-2 infections) nationwide in Japan. Vaccine effectiveness of BNT162b2 or mRNA-1273 against symptomatic SARS-CoV-2 infections was evaluated. Waning immunity among patients aged 16-64 years was also assessed. RESULTS: We enrolled 1936 patients, including 396 test-positive cases and 1540 test-negative controls for SARS-CoV-2. The median age was 49 years, 53.4% were male, and 34.0% had underlying medical conditions. Full vaccination (receiving 2 doses ≥14 days before symptom onset) was received by 6.6% of cases and 38.8% of controls. Vaccine effectiveness of full vaccination against symptomatic SARS-CoV-2 infections was 88.7% (95% confidence interval [CI], 78.8%-93.9%) among patients aged 16-64 years and 90.3% (95% CI, 73.6%-96.4%) among patients aged ≥65 years. Among patients aged 16-64 years, vaccine effectiveness was 91.8% (95% CI, 80.3%-96.6%) within 1-3 months after full vaccination, and 86.4% (95% CI, 56.9%-95.7%) within 4-6 months. CONCLUSIONS: mRNA COVID-19 vaccines had high effectiveness against symptomatic SARS-CoV-2 infections in Japan during July-September 2021, when the Delta variant was dominant nationwide.

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.

Effectiveness of mRNA COVID-19 vaccines against symptomatic SARS-CoV-2 infections during the SARS-CoV-2 Omicron BA.1 and BA.2 epidemic in Japan: vaccine effectiveness real-time surveillance for SARS-CoV-2 (VERSUS).

BACKGROUND: Evaluating COVID-19 vaccine effectiveness (VE) domestically is crucial for assessing and determining national vaccination policy. This study aimed to evaluate VE of mRNA COVID-19 vaccines in Japan. METHODS: We conducted a multicenter test-negative case-control study. The study comprised individuals aged ≥16 visiting medical facilities with COVID-19-related signs or symptoms from 1 January to 26 June 2022, when Omicron BA.1 and BA.2 were dominant nationwide. We evaluated VE of primary and booster vaccination against symptomatic SARS-CoV-2 infections and relative VE of booster compared with primary. RESULTS: We enrolled 7,931 episodes, including 3,055 test positive. The median age was 39, 48.0% were male, and 20.5% had underlying medical conditions. In individuals aged 16 to 64, VE of primary vaccination within 90 days was 35.6% (95% CI, 19.0-48.8%). After booster, VE increased to 68.7% (60.6-75.1%). In individuals aged ≥65, VE of primary and booster was 31.2% (-44.0-67.1%) and 76.5% (46.7-89.7%), respectively. Relative VE of booster compared with primary vaccination was 52.9% (41.0-62.5%) in individuals aged 16 to 64 and 65.9% (35.7-81.9%) in individuals aged ≥65. CONCLUSIONS: During BA.1 and BA.2 epidemic in Japan, mRNA COVID-19 primary vaccination provided modest protection. Booster vaccination was necessary to protect against symptomatic infections.

[Assessing the efficacy of antimicrobial agents based on the Japanese Respiratory Society Guidelines for a community-acquired pneumonia].

We evaluated the efficacy of antimicrobial agents used for patients with community-acquired pneumonia (CAP) based on the guidelines of Japanese Respiratory Society. A total of ninety-nine hospitalized patients who were suspected to have bacterial pneumonia at the time of admission between January, 1998 and December, 2000 were assessed. Our conclusions were as follows. 1) The rate which was considered as effective by the guidelines were 83.3% (5 of 6 cases), 98.7% (74 of 75 cases), 85.7% (12 of 14 cases), and 100% (4 of 4 cases) for penicillin, cephem, carbapenem and tetracycline, respectively. 2) These guidelines were useful and practical for identifying the etiological organisms, determining the severity of pneumonia and evaluating the efficacy of chemotherapeutic agents in CAP. 3) Gram-positive organisms were isolated more frequently among the "mild" group. The number of isolated gram-negative was increased significantly as the severity of pneumonia progressed from "mild" to "severe" group. 4) Factors such as body temperature and white cells count were not always applicable for evaluating the clinical effect in elderly cases. 5) Risk factors such as underlying diseases, or complications, age (over eighty years old) and specific etiological organisms might influence the ineffectiveness of antimicrobial agents among the cases that had no clinical response. 6) The choice of antibiotic agents for the treatment of CAP should be made with consideration to the local-specific profiles of each medical facility as described in the guidelines.

[A successful treatment of Vibrio vulnificus infection].

A 65-year-old male patient with a history of alcoholism visited our outpatient clinic complaining of nausea and diarrhea followed by dizziness. Erythema and swelling with partial exfoliation on the right forearm to hand and right thigh were noticed. Vibrio vulnificus was isolated from the purulent discharge of the skin. Due to urgent and intensive treatment of bacterial shock and antimicrobial drugs, the patient fully recovered three months later. We believe that the patient survived from this fatal infection because; 1) the isolates were highly sensitive to a wide variety of antibiotics, 2) the antibiotic therapy was started immediately, with an alternative usage of different antibiotics, and 3) the liver dysfunction of the patient had not been severely damaged by alcohol before the infection.

[A case of Bartonella henselae infection from a dog].

A 50-year-old male with left cervical lymphadenopathy visited our hospital. Infectious and lymphomatous diseases were suspected in the patient. Since the patient owned a dog, which often licked the patient's face, Bartonella infection was also suspected. Histopathological examination in the lymph node biopsy revealed the epithelioid granuloma, but B. henselae was not detected from the culture of the lymphnode. B. henselae DNA also was not detected from the lymph node. Since the antibody titer (lgG) to B. henselae showed 1:128 by immunofluorescent antibody technique (IFA), he was serdogicalg diagnosed as cat-scratch disease. 'Cat-scratch disease' is named after cat scratch, however we propose 'B. henselae infection' which is more appropriate since other animals could serve as a cause of infection.