Dynamics of anti-Spike IgG antibody titer after the third BNT162b2 COVID-19 vaccination in the Japanese health care workers

IntroductionMany countries are administering a third dose of some coronavirus disease 2019 (COVID-19) vaccines, but the evaluation of vaccine-induced immunity is insufficient. This study aimed to evaluate anti-spike immunoglobulin G (IgG) titers in the health care workers after the third BNT162b2 vaccination. MethodsDynamics of anti-spike IgG titers were assessed two months following the third BNT162b2 vaccination in 52 participants. All participants received the primary series of vaccination with BNT162b2 and received the third dose eight months after the second vaccination. Associations between anti-spike IgG titer, baseline characteristics, and adverse reactions were also evaluated. ResultsThe geometric mean titer of anti-spike IgG one month after the third vaccination was 17400 AU/ml, which increased to approximately 30 times immediately before the third vaccination and approximately twice that one month after the second vaccination. In addition, participants with anti-spike IgG titers less than 10000 AU/ml after the second vaccination tended to have higher increases in ant-spike IgG titers before and after the third vaccination. The decline rate of anti-spike IgG was significantly slower after the third vaccination as 35.7% than that after the second vaccination as 59.1%. The anti-spike IgG titer was significantly negatively associated with age (r = -0.31). Participants who had a headache at the vaccination showed significantly higher anti-spike IgG titer than those without a headache. ConclusionsThe anti-spike IgG induced by primary immunization with BNT162b2 waned over time. The third dose of BNT162b2 substantially increased the anti-spike IgG with a slower decline rate.

Dynamics of anti-Spike IgG antibody level after full BNT162b2 COVID-19 vaccination in health care workers

IntroductionThe administration of a third vaccine is ongoing in many countries, but the evaluation of vaccine-induced immunity is still insufficient. This study evaluated anti-spike IgG levels in 373 health care workers six months after the BNT162b2 vaccination. MethodsDynamics of anti-spike IgG levels six months after the 2nd vaccination were assessed in 49 participants (Analysis-1). A cross-sectional assessment of anti-spike IgG level was performed in 373 participants (Analysis-2). Participants positive for anti-nucleocapsid IgG or IgM and receiving immunosuppressants were excluded from Analysis-2. ResultsIn Analysis 1, the median anti-spike IgG level was lower in the older age group and decreased consistently after the second vaccination regardless of age. In Analysis-2, the anti-spike IgG level was significantly negatively associated with age (r = -0.35, p < 0.01). This correlation remained statistically significant (r = -0.28, p < 0.01) even after adjusting for sex, BMI, smoking habits, alcohol drinking habits, allergies, and the presence of fever or other adverse reactions at the time of the vaccination. Alcohol drinking habit was also associated with the anti-spike IgG level; daily alcohol drinkers had significantly lower anti-spike IgG levels than never alcohol drinkers. Sex, smoking habit, allergy, and fever and other side effects after the vaccination were not associated with anti-spike IgG levels six months after the 2nd vaccination. ConclusionsSix months after the vaccination, the anti-spike IgG level was substantially low among older persons and daily alcohol drinkers.

Reproducibility and validity of food group intake in a short food frequency questionnaire for the middle-aged Japanese population

PURPOSE@#The purpose of this study was to evaluate the reproducibility and validity of a short food frequency questionnaire (FFQ) for food group intake in Japan, the reproducibility and partial validity of which were previously confirmed for nutrients.@*METHODS@#A total of 288 middle-aged healthy volunteers from 11 different areas of Japan provided nonconsecutive 3-day weighed dietary records (DRs) at 3-month intervals over four seasons. We evaluated reproducibility based on the first (FFQ1) and second (FFQ2) questionnaires and their validity against the DRs by comparing the intake of 20 food groups. Spearman's rank correlation coefficients (SRs) were calculated between energy-adjusted intake from the FFQs and that from the DRs.@*RESULTS@#The intake of 20 food groups estimated from the two FFQs was mostly equivalent. The median energy-adjusted SRs between the FFQ1 and FFQ2 were 0.61 (range 0.38-0.86) for men and 0.66 (0.45-0.84) for women. For validity, the median de-attenuated SRs between DRs and the FFQ1 were 0.51 (0.17-0.76) for men and 0.47 (0.23-0.77) for women. Compared with the DRs, the proportion of cross-classification into exact plus adjacent quintiles with the FFQ1 ranged from 58 to 86% in men and from 57 to 86% in women. According to the robust Z scores and the Bland-Altman plot graphs, the underestimation errors in the FFQ1 tended to be greater in individuals with high mean levels of consumption for meat for men and for other vegetables for both men and women.@*CONCLUSION@#The FFQ demonstrated high reproducibility and reasonable validity for food group intake. This questionnaire is short and remains appropriate for identifying associations between diet and health/disease among adults in Japan.

Treatment for Eradication of Helicobacter pylori Infection among Chronic Hepatitis C Patients

BACKGROUND/AIMS: Helicobacter pylori infection causes gastritis, peptic ulcers and gastric malignancies, and its eradication has been advocated by many groups. We determined the H. pylori carrier status and eradication rates of patients with chronic hepatitis C virus (HCV) infection. METHODS: In total, 76 chronically HCV-infected patients were enrolled for comparison with 228 HCV-noninfected, age- and sex-matched controls. H. pylori infection was confirmed by H. pylori antibody and urea breath testing. RESULTS: The H. pylori infection rate was significantly higher for HCV-infected patients (67 of 76, 88.2%) than for HCV-noninfected controls (158 of 228, 69.3%). Endoscopic findings showed that the rates of gastric ulcers and gastritis were significantly higher for the 67 HCV-infected patients with H. pylori infection (34.3% and 77.6%) than for the 158 HCV-noninfected controls with H. pylori infection (15.2% and 57.6%). Treatment to eradicate H. pylori had a significantly higher success rate for HCV-infected patients (61 of 67, 91.0%) than for HCV-noninfected controls (115 of 158, 72.8%). CONCLUSIONS: The markedly high H. pylori eradication rate observed in this study shows that eradication of H. pylori holds promise for the improvement of the long-term health condition of patients with chronic HCV infection.