The period of use for hand disinfectants after opening of their container bottles varies among facilities, depending on each facility's regulations. Several facilities adopt a half-year period after opening. In order to assess the sterilizing activities after 6 months, we collected gel-like alcohol formulations (disinfectants) that were actually used in our hospital, stored them at room temperature up to 34 months, and measured the ethanol concentration, which is the main active component, by gas chromatography.

We found, unexpectedly, that regardless of the remaining amount and elapsed time after opening, the ethanol concentrations did not differ from that in the samples from freshly opened bottles. To verify this result, the bactericidal activity of each sample was measured using Staphylococcusaureus and Pseudomonas aeruginosa. Ninety μL of each sample was mixed with 10 μL of bacterial fluid; after 30sec or 5 min, the bacterial titer was determined by colony-formation assay on agar plates. The bactericidal activity was evaluated by the rate of decrease and log₁₀ reduction, using water as control. Liquid formulations were also measured to compare with the gel-like formulations.

The results showed that the bactericidal activities also did not differ from those of the samples from freshly opened bottles, similar to the results for the ethanol concentration.

In conclusion, gel-like formulations contain sufficient ethanol concentrations and are effective against S. aureus and P. aeruginosa even beyond 6 months after opening.

Background: Sotrovimab is a human monoclonal antibody that targets a domain of the novel coronavirus (SARS-CoV-2) spike protein distinct from the ACE2 receptor binding site. In an overseas phase III study (COMET-ICE) in adult patients with mild to moderate coronavirus disease 2019 (COVID-19) at high risk for disease progression, treatment with sotrovimab (a single 500 mg intravenous (IV) dose) reduced the risk of hospitalization >24 hours and death by 79% compared with placebo, and the drug was well tolerated. In Japan, a special approval granted in September 2021 allows the use of IV sotrovimab in patients with SARS-CoV-2 infection who have risk factors for severe COVID-19 and do not require oxygen administration.

Objective: The present study was designed to evaluate whether ethnic-dependent differences in drug exposure and safety exist between healthy adult Japanese and Caucasian populations after receiving 500 mg IV sotrovimab.

Methods: we evaluated the safety, tolerability, and pharmacokinetics of a single 500 mg IV dose of sotrovimab in healthy Japanese and Caucasian subjects. Subjects were randomized in a 4: 1 ratio to receive a single, 500 mg IV infusion of sotrovimab or volume-matched saline placebo. The primary endpoints were the safety and pharmacokinetics of sotrovimab up to 29 days post-dosing.

Results/Conclusion: When a single 500 mg IV dose of sotrovimab was administered to healthy subjects, no serious adverse events were reported in any subject, and sotrovimab was similarly well-tolerated in both ethnic groups. There was no apparent effect of ethnicity on the pharmacokinetic exposure of sotrovimab. The results support the approved dose and route of administration (a single 500 mg intravenous dose) in Japan.

Herein, we report three pregnant women who gave birth while suffering from coronavirus disease 2019 (COVID-19). All of the newborns tested negative for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at birth and 48 hours later. In all of these cases, the main issues were how long to continue breastfeeding restrictions and mother-infant separation after delivery. With reference to prior reports, we examined the measures taken in each case. In case 1, breastfeeding restriction and mother-infant separation were continued until the patient satisfied the COVID-19 discharge criteria of the Ministry of Health, Labour and Welfare, and her nasopharyngeal SARS-CoV-2 polymerase chain reaction (PCR) test result was negative. However, since the nasopharyngeal SARS-CoV-2 PCR test result can be positive for a long period of time, we thought that it would be impractical to restrict breastfeeding or to continue mother-infant separation until the test results were confirmed to be negative in all cases. Thus, in the other cases, SARS-CoV-2 PCR testing of the breast milk was conducted once it was produced, and indirect breastfeeding was performed after the test results were negative. Mother-infant separation was discontinued after the nasopharyngeal SARS-CoV-2 qualitative antigen test result was negative, and the infants did not develop any COVID-19 symptoms. It has been reported that breast milk from mothers with COVID-19 is more likely to contain SARS-CoV-2-specific antibodies. In the future, we will investigate the possibility of shortening the mother-infant separation period by early initiation of breastfeeding.

This study was aimed at evaluating the changes in the antibody titers and neutralization ability before and after inoculation with an mRNA COVID-19 vaccine (Pfizer, USA) among healthcare professionals (HCPs) in Japan. A total of 221 HCPs were enrolled and their blood samples were collected at three time points: 1) before vaccination, 2) 3 weeks after the first dose, and 3) 3 weeks after the second dose. The titers of anti-SARS-CoV-2 Spike protein IgG antibody were measured in all the samples using VITROS-Anti-SARS-CoV-2 S1 Quant IgG Antibody (CLEIA, Ortho-Clinical Diagnostics, Inc. ), and the surrogate Virus Neutralization Test (sVNT) (ELISA, GenScript, USA) was performed in the samples obtained after the vaccination. The anti-SARS-CoV-2 IgG titers were 1) median: 0.16; Interquartile (IQR): 0.10-0.27, 2) median: 250; IQR: 99.5-466 and 3) median: 2,400; IQR: 1,480-3,950, respectively, at the three time-points. Our study also revealed the relationship between the anti-SARS-CoV-2 IgG antibody titer and the antibody neutralization activity.

Objective: We investigated whether there was a difference in the antibody profile after Pfizer/BioNtech vaccination in persons who had already been infected with COVID-19 and those who had not.

Method: Blood samples were obtained before, after the first dose and after the second dose of Pfizer/BioNtech vaccine inoculation in 4 subjects with a history of COVID-19 infection and 62 subjects without a history of COVID-19 infection after obtaining their informed consent. The differences in the antibody titers were examined between those with and without a prior history of COVID-19.

Result: As compared with those without a prior history of COVID-19, those with a prior history of COVID-19 showed significantly higher antibody titers after the first inoculation, and the antibody titers were significantly higher than even those after the second inoculation of subjects without a prior history of COVID-19.

Conclusion: Our findings suggest that a single vaccine dose may be sufficient for subjects with a prior history of COVID-19.

The global pandemic of Novel Coronavirus Disease (COVID-19) has highlighted the importance of clinicians having universal knowledge and skills in infection prevention. Herein, we report the results of a questionnaire survey regarding mandatory training in infectious diseases (ID) in a Japanese residency program. The questionnaire collected information on the gender, post-graduate year, and the necessity and feasibility of, and expectation from the program. Responses were obtained from 127 respondents (74 residents [58.3%] and 53 fellows [41.7%] ). The majority (98.4%) indicated that ID training during a residency program is important, and that its importance was augmented by the COVID-19 pandemic. Notably, 66.1% of the respondents agreed with the need for mandatory ID training; however, 21.3% pointed out the possibility of not being able to receive adequate training in the current programs. To prepare and confront a future ID crisis, it may be time to discuss mandatory ID training in clinical residency programs.