Publications by authors named "Natsumi Inamura"
Background: Dexamethasone is currently administered for Coronavirus disease 2019(COVID-19); however, there are concerns about its effect on specific antibodies' production. The aim of this study was to evaluate whether specific antibodies were affected by COVID-19 severity and corticosteroid treatment.
Methods: Of 251 confirmed COVID-19 patients admitted to our hospital between January 26 and August 10, 2020, the early period of the pandemic, 75 patients with sera within 1 month of onset and 1 month or longer were included in the research.
Background: Data are limited on the protective role of the Omicron BA bivalent vaccine, previous infection, and their induced neutralizing antibodies against Omicron XBB.1.16 and EG.
View Article and Find Full Text PDFBackground: We aimed to examine the association among nucleocapsid (N) antibodies, a combination of N and spike (S) antibodies, and protection against SARS-CoV-2 reinfection.
Methods: We conducted a prospective cohort study among staff at a national medical research center in Tokyo and followed them for the incidence of SARS-CoV-2 infection between June and September 2023 (Omicron XBB.1.
Background & Aims: Vitamin D deficiency is a common nutritional problem worldwide that may have worsened during the coronavirus disease 2019 (COVID-19) pandemic. The present study sought to examine the prevalence and correlates of vitamin D deficiency among healthcare workers three years after the start of the COVID-19 pandemic.
Methods: Participants comprised 2543 staff members from a medical research institute, who completed a questionnaire and donated blood samples in June 2023.
Article Synopsis
- - This study explores the effectiveness of antibody testing for assessing immunity and diagnosing conditions like multisystem inflammatory syndrome related to COVID-19, focusing on antibodies targeting the SARS-CoV-2 spike protein.
- - Researchers measured the neutralizing activity of immunoglobulin-G (IgG) in COVID-19 convalescent patients, finding a strong correlation between serum neutralizing activity (IgG-EC) and specific antibodies (S-IgG).
- - The findings suggest that quantitative S-IgG tests can reliably estimate neutralizing antibody activity, provided the cut-off values for interpreting results are carefully established for accuracy.
Background: Data are limited on the role of preinfection humoral immunity protection against Omicron BA.5 infection and long coronavirus disease (COVID) development.
Methods: We conducted nested case-control analysis among tertiary hospital staff in Tokyo who donated blood samples in June 2022 (1 month before Omicron BA.
Objectives: To examine the differences in durability and its determinants of humoral immunity following 2- and 3-dose COVID-19 vaccination.
Methods: Throughout the pandemic, we evaluated the anti-spike IgG antibody titers of 2- and 3-dose mRNA vaccine recipients over time among the staff of a medical and research center in Tokyo. Linear mixed models were used to estimate trajectories of antibody titers from 14 to 180 days after the last immune-conferred event (vaccination or infection) and compare antibody waning rates across prior infection and vaccination status, and across background factors in infection-naïve participants.
Background: Amoxicillin plus probenecid is an alternative to intramuscular benzathine penicillin G for treating syphilis in the United Kingdom. Low-dose amoxicillin is an alternative treatment option used in Japan.
Methods: We conducted an open-label, randomized, controlled, non-inferiority trial between 31 August 2018, and 3 February 2022, to compare 1500 mg low-dose amoxicillin monotherapy with the combination of 3000 mg amoxicillin and probenecid (non-inferiority margin 10%).
Background: Longitudinal data are lacking to compare booster effects of Delta breakthrough infection versus third vaccine dose on neutralizing antibodies (NAb) against Omicron.
Methods: Participants were the staff of a national research and medical institution in Tokyo who attended serological surveys on June 2021 (baseline) and December 2021 (follow-up); in between, the Delta-dominant epidemic occurred. Of 844 participants who were infection-naïve and had received two doses of BNT162b2 at baseline, we identified 11 breakthrough infections during follow-up.
To describe the trend of cumulative incidence of coronavirus disease 19 (COVID-19) and undiagnosed cases over the pandemic through the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants among healthcare workers in Tokyo, we analysed data of repeated serological surveys and in-house COVID-19 registry among the staff of National Center for Global Health and Medicine. Participants were asked to donate venous blood and complete a survey questionnaire about COVID-19 diagnosis and vaccine. Positive serology was defined as being positive on Roche or Abbott assay against SARS-CoV-2 nucleocapsid protein, and cumulative infection was defined as either being seropositive or having a history of COVID-19.
View Article and Find Full Text PDFObjectives: To investigate the role of immunogenicity after the third vaccine dose against Omicron infection and COVID-19-compatible symptoms of infection.
Methods: First, we examined vaccine effectiveness (VE) of the third dose against the second dose during the Omicron wave among the staff at a tertiary hospital in Tokyo. In a case-control study of third vaccine recipients, we compared the preinfection live-virus neutralizing antibodies (NAb) against Omicron between breakthrough cases and their controls who had close contact with patients with COVID-19.
Objective: This study aimed to examine the sex-associated differences in the relationship between dyslipidemia and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike immunoglobulin (Ig)G antibodies among BNT162b2 vaccine recipients.
Methods: Participants were staff members (aged 21-75 years) of a medical and research institution who underwent an anti-SARS-CoV-2 spike IgG antibody test after the second (n = 1872) and third doses (n = 1075) of the BNT162b2 vaccine. Dyslipidemia was defined as triglyceride level ≥150 mg/dl, high-density lipoprotein-cholesterol level <40 mg/dl, low-density lipoprotein-cholesterol level ≥140 mg/dl, or lipid-lowering medication use.
Background: Increased γ-glutamyl transpeptidase (GGT) levels can deplete plasma glutathione, which in turn impairs immune regulation; however, evidence on GGT levels and post-vaccine immunogenicity is lacking.
Objective: To examine the association between GGT and SARS-CoV-2 spike IgG antibodies.
Methods: Participants were 1479 medical staff (aged 21 to 75 years) who received a SARS-CoV-2 antibody test after their second vaccine and whose GGT levels were measured before the vaccine rollout.
Background: Hyperglycemia can alter the activation of innate and acquired immunity, but epidemiological evidence linking hyperglycemia to post-vaccination immunogenicity is limited. Objective: To examine the association between SARS-CoV-2 spike antibody titers after the COVID-19 vaccine and impaired fasting glucose (IFG) and diabetes. Methods: Participants were 953 health care workers aged 21−75 years who were tested for SARS-CoV-2 spike IgG antibodies and underwent a health checkup two months after their second dose of the BNT162b2 vaccine.
View Article and Find Full Text PDFObjective: This study investigated the sex-associated difference in the impact of obesity on antibody response to a COVID-19 vaccine.
Methods: This study included 2,435 health care workers who received two doses of the BioNTech, Pfizer (BNT162b2) vaccine and participated in a serological survey, during which they were tested for anti-SARS-CoV-2 spike immunoglobin G (IgG) antibodies and asked for information on height, weight, and vaccination history via a questionnaire. Multivariable linear regression analysis was used to estimate the geometric mean titers (GMT) of antibodies for each sex and BMI category.