Effectiveness of mRNA COVID-19 vaccines against symptomatic SARS-CoV-2 infections during the Delta variant epidemic in Japan: Vaccine Effectiveness Real-time Surveillance for SARS-CoV-2 (VERSUS)

BackgroundAlthough high vaccine effectiveness of messenger RNA (mRNA) coronavirus disease 2019 (COVID-19) vaccines was reported in studies in several countries, data is limited from Asian countries, especially against the Delta (B.1.617.2) variant. MethodsWe conducted a multicenter test-negative case-control study in patients aged [≥]16 visiting hospitals or clinics with signs or symptoms consistent with COVID-19 from July 1 to September 30, 2021, when the Delta variant was dominant ([≥]90% of severe acute respiratory syndrome coronavirus 2 [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 to 64 was also assessed. ResultsWe 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 two 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 to 64 and 90.3% (95% CI, 73.6-96.4) among patients aged [≥]65. Among patients aged 16 to 64, vaccine effectiveness within one to three months after full vaccination was 91.8% (95% CI, 80.3-96.6), and was 86.4% (95% CI, 56.9-95.7) within four to six months. ConclusionsmRNA COVID-19 vaccines had high effectiveness against symptomatic SARS-CoV-2 infections in Japan during July 1 to September 30, 2021, when the Delta variant was dominant nationwide.

PECULIARITY OF MUSCLE STRENGTH IN THE LOWER LIMBS OF SOCCER PLAYERS FROM THE PERSPECTIVE OF ISOKINETIC MUSCLE STRENGTH AND MRI FINDINGS IN COMPARISON WITH THOSE OF ARCHERS / 体力科学

This study examined peculiarities in both muscle strength and cross-sectional area (CSA) among soccer players in comparison with those of archers as contrasting athletes. Subjects were 15 male soccer players and 9 male archers at N University. Measurement items were height, body weight (BW), isokinetic muscle strength (knee extension, knee flexion, hip extension, hip flexion) and CSA (psoas muscles). Isokinetic muscle strength (30, 120, 240°/sec.) was measured by Cybex6000 (Lumex Co.), and the psoas muscle CSA was determined using magnetic resonance imaging (Hitachi, Japan). Results were as follows : 1. There was no significant difference in isokinetic knee extension and flexion strength/BW at all angular velocities between soccer players and archers. 2. On isokinetic hip flexion strength/BW, the average values of soccer players were significantly higher at all angular velocities than those of archers. However, there was no significant difference in the average values of isokinetic hip extension strength at all angular velocities between the two groups. 3. The average value for the psoas muscle CSA in soccer players was significantly higher than that of archers. In this study, the biggest difference in muscle strength between soccer players and archers was hip flexion strength, and the CSA of the psoas muscle in soccer players, which is the main component of hip flexion, was significantly larger than that of archers. These findings showed the peculiarity of soccer players due to the constant demands of movements involved in ball kicking and running during practice and competition.