Bacillus Calmette-Guérin vaccination as defense against SARS-CoV-2 (BADAS): a randomized controlled trial to protect healthcare workers in the USA by enhanced trained immune responses.

BACKGROUND: A large epidemic, such as that observed with SARS-CoV-2, seriously challenges available hospital capacity, and this would be augmented by infection of healthcare workers (HCW). Bacillus Calmette-Guérin (BCG) is a vaccine against tuberculosis, with protective non-specific effects against other respiratory tract infections in vitro and in vivo. Preliminary analyses suggest that regions of the world with existing BCG vaccination programs have lower incidence and mortality from COVID-19. We hypothesize that BCG vaccination can reduce SARS-CoV-2 infection and disease severity. METHODS: This will be a placebo-controlled adaptive multi-center randomized controlled trial. A total of 1800 individuals considered to be at high risk, including those with comorbidities (hypertension, diabetes, obesity, reactive airway disease, smokers), racial and ethnic minorities, elderly, teachers, police, restaurant wait-staff, delivery personnel, health care workers who are defined as personnel working in a healthcare setting, at a hospital, medical center or clinic (veterinary, dental, ophthalmology), and first responders (paramedics, firefighters, or law enforcement), will be randomly assigned to two treatment groups. The treatment groups will receive intradermal administration of BCG vaccine or placebo (saline) with groups at a 1:1 ratio. Individuals will be tracked for evidence of SARS-CoV-2 infection and severity as well as obtaining whole blood to track immunological markers, and a sub-study will include cognitive function and brain imaging. The majority of individuals will be followed for 6 months, with an option to extend for another 6 months, and the cognitive sub-study duration is 2 years. We will plot Kaplan-Meier curves that will be plotted comparing groups and hazard ratios and p-values reported using Cox proportional hazard models. DISCUSSION: It is expected this trial will allow evaluation of the effects of BCG vaccination at a population level in high-risk healthcare individuals through a mitigated clinical course of SARS-CoV-2 infection and inform policy making during the ongoing epidemic. TRIAL REGISTRATION: ClinicalTrials.gov NCT04348370. Registered on April 16, 2020.

Effect of drysuit seals on intraocular pressure in non-immersed scuba divers.

Objective: This study quantifies the change in intraocular pressure (IOP) secondary to wearing neck seals in scuba diving drysuits. Previous work demonstrates significant pressures exerted by these seals; we hypothesize that they would. Methods: IOP was measured in 33 divers before and while wearing a drysuit using rebound tonometry. The drysuit neck seal pressures were measured using a manometer. A paired two-sample t-test was used to compare IOP before and after drysuit donning. Pearson correlation coefficients were calculated between neck sealing pressures and IOP by side. Results: The mean IOP in the right eye was similar pre- and post-drysuit donning, with baseline mean 15.9 mmHg (3.7 mmhg) versus 15.4 mmHG (4.3 mmHg) post-donning, p=0.41. Similarly, the mean IOP in the left eye was also similar, with mean pre-donning IOP 15.6 (3.8 mmHg) versus 15.4 mmHg (4.7 mmHg) post-donning, p=0.75. The mean right and left neck seal pressures were 23.66 (10.60) mmHg and 23.67 (7.87) mmHg, respectively. Only the correlation between right neck sealing pressure for silicone neck seals and right IOP, pre- and post-donning was significant (pre: 0.97, p-value 0.03, post: 0.98, p-value 0.02). Conclusion: No significant difference overall was detected in IOP with drysuit donning.

Quantifying drysuit seal pressures in non-immersed scuba divers.

INTRODUCTION: Drysuits use flexible neck and wrist seals to maintain water-tight seals. However, if the seals exert too much pressure adverse physiological effects are possible, including dizziness, lightheadedness, syncope, and paresthesias in the hands. We aimed to quantify the seal pressures of neck and wrist seals in non-immersed divers. METHODS: We recruited 33 diving volunteers at two dive facilities in High Springs, Florida. After a history and physical exam, we measured vital signs as well as wrist and neck seal pressures using a manometer system. RESULTS: The mean (SD) seal pressure of the right wrist seals was found to be 38.8 (14.9) mmHg, while that of the left wrist seals was 37.6 (14.9) mmHg. The average neck seal pressure was 23.7 (9.4) mmHg. Subgroup analysis of seal material demonstrated higher mean sealing pressure with latex seals compared to silicone; however, this difference was not statistically significant. CONCLUSIONS: Drysuit seal pressures are high enough to have vascular implications and even potentially cause peripheral nerve injury at the wrist. Divers should trim their seals appropriately and be vigilant regarding symptoms of excessive seal pressures. Further research may elucidate if seal material influences magnitude of seal pressure.