· Researchers from Thailand reviewed epidemiological data on universal Bacillus Calmette-Guérin (BCG) vaccination and found that countries without universal BCG vaccination have the highest number of COVID-19 deaths. They attribute this to the theory that the BCG vaccine enhances both adaptive and innate immune response for viral clearance though acknowledge that the supporting evidence is limited.
· A retrospective study including 442 patients with COVID-19 found that male sex was the factor most associated with greater illness severity. Additionally, older age, African American race, obesity, and pre-existing conditions such as hypertension and diabetes mellitus were associated with higher illness severity while individuals chronically using ACE inhibitors had less severe illness.
Understanding the Pathology
· A case series from the Netherlands describes 4 young, previously healthy, male patients in their 20s (2 pairs of brothers from unrelated families) with severe COVID-19 who required mechanical ventilation in the ICU. Genetic sequencing of these patients found two different loss of function variants of TLR-7, resulting in diminished type I and II interferon activity when compared to healthy controls. These findings point to potential genetic predispositions that increase the risk of developing severe COVID-19.
Transmission and Prevention
· A study conducted at the National Biodefense Analysis and Countermeasures Center in Maryland, United States found that SARS-CoV-2 decays rapidly in simulated sunlight though the rate was dependent on the aerosol suspension matrix as well as the intensity of simulated sunlight, whereas the relative humidity did not significantly affect the decay rate.
· A systematic review and meta-analysis of 14 studies, including 10,127 patients, explored the relationship between angiotensin-converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs), and the morbidity and mortality of COVID-19. Results revealed no increase in morbidity or mortality in COVID-19 patients taking ACEIs/ARBs and provides continued support for their safety amid the pandemic.
Adjusting Practice During COVID-19
· Surgical oncologists from Massachusetts General Hospital created a risk stratification scoring system for breast cancer patients whose surgeries were delayed due to COVID-19. The score considers patient and tumor characteristics, length of delay, and tumor response to neoadjuvant chemotherapy and was found to agree with experienced surgeons' judgement when validated. The authors offer this score as a tool to prioritize higher risk patients as surgeries resume.
R&D: Diagnosis and Treatments
· A group of researchers validated 3 different SARS-CoV-2 antibody assays, including one chemiluminescent test (Abbott COVID-2 IgG) and two lateral flow tests (STANDARD Q IgM/IgG Duo and Wondfo Total Antibody Test). Each assay detected antibodies in 100% of all COVID-19 positive samples by 2 weeks after symptom onset, with only SQ IgM showing suboptimal results (85.7% positive rate). The authors support the use of serological testing in COVID-19 as part of diagnostic testing, particularly 14 days after symptom onset.
· Researchers conducted a systematic review and meta-analysis of 29 studies (including randomized control studies, prospective and retrospective studies involving a total of 5,207 total patients) which examined outcomes of COVID-19 patients treated with hydroxychloroquine, remdesivir, ritonavir/lopinavir, convalescent plasma therapy, and tocilizumab. Results revealed that hydroxychloroquine was associated with increased morbidity and mortality and none of the other interventions significantly changed the course of COVID-19 infection outcomes, though further study is indicated.