· What does the literature say about face mask usage against COVID-19? A large international, interdisciplinary group summarize the evidence supporting mask wearing to mitigate the spread of COVID-19. They reviewed direct epidemiological evidence, population-level impacts, transmission characteristics, laboratory-based source control experiments, personal protective equipment efficacy research, sociological considerations, and implementation policies. Authors conclude all evidence indicates mask wearing effectively reduces viral droplet transmission and should be encouraged by officials to help minimize the spread of COVID-19.
Understanding the Pathology
· ABO blood group showed minimal differences in SARS-CoV-2 antibody response but blood group B had higher neutralizing antibody titers. A multicenter prospective cohort study conducted by Johns Hopkins University, Mississippi Valley Regional Blood Center in Springfield, IL, Washington University School of Medicine in St. Louis, MO, Mayo Clinic in Rochester, MN, and National Institute of Health in Baltimore, MD involved 202 individuals who were eligible to donate COVID-19 convalescent plasma at the beginning of the pandemic. They found there was no difference in anti-SARS-CoV-2 spike IgA or IgG between ABO groups, but significantly higher neutralizing antibody (nAb) titers were present in blood group B (44%) compared to blood groups A (25%), O (20%) and AB (0%). These findings suggest blood group B may have higher nAb titers after recovery from COVID-19 infection and thus greater protection against future infection with SARS-CoV-2, however further studies correlating ABO blood groups and disease severity are needed to further support these findings.
· Microthrombi is a major cause of cardiac injury in COVID-19. A pathologic analysis conducted by CVPath Institute, Inc and the University of Maryland of 40 autopsied hearts of patients who died while hospitalized for COVID-19 at Ospedale Papa Giovanni XXIII hospital in Bergamo, Italy found the microthrombi isolated in COVID-19 patients were richer in fibrin and terminal compliment immunostaining compared to aspirated thrombi from percutaneous coronary intervention in other COVID-19 infected and uninfected patients with STEMI. This is most likely due to SARS-CoV-2 activation of multiple compliment levels. Microthrombi were found to be significantly associated with focal myocyte necrosis in 82% (9/11) cases of the 14 overall cases with myocyte necrosis. These findings suggest the majority of cardiac injury found in subjects dying with COVID-19 is due to cardiac microthrombi, indicating a likely cause of cardiac injury among hospitalized COVID-19 patients, and highlights need for further studies on the targeted use of anti-platelet, anti-coagulant, and anti-complement therapies specifically tailored for microthrombi.
Transmission & Prevention
· Further robust research is necessary to deduce the link, if any between COVID-19 vaccination efficacy and obesity. Researchers from Harvard Medical School, Massachusetts General Hospital and ConscienHealth in Pittsburgh refute previous speculations that obesity could be associated with reduced efficacy of the COVID-19 vaccines. Data from Phase 3 vaccine trial results show Pfizer-BioNTech has 95.4% efficacy (CI: 86.0 - 99.1%) in people with obesity compared to 94.8% (CI: 87.4-98.3%) in people without obesity and Moderna efficacy of 91.2% (CI:32.0-98.9%) in people with severe obesity and 94.8% (CI: 89.3-96.8%) overall. Since obesity is one of the most significant risk factors for severe outcomes from COVID-19, these authors suggest that ongoing placebo-controlled vaccine trials designed with necessary power for detecting differences among classes of obesity are important for post-vaccine risk stratification and public health strategy. · A nanomechanical study found SARS-CoV-2 to survive best on polystyrene compared to other tested inanimate surfaces. A nanomechanical study by researchers in Alberta, Canada and Changsha, Shenzhen, and Guangdong, China tested SARS-CoV-2 survival on four different surfaces and found that the spike protein on the outer surface of the SARS-CoV-2 virion, which is responsible for transmission via fomites, survived the best on polystyrene, then stainless steel, then gold, and then on glass, suggesting that fomite transmission of SARS-CoV-2 is prevalent and that more surfaces need to be tested to get a better understanding for both prevention and tracking transmission of the virus.