Understanding the Pathology
· Italian microbiologists report on a novel SARS-CoV-2 variant (VOC-202012/01) in a 59-year-old man who presented in November 2020 with persistent SARS-CoV-2 positivity since August. Metagenomic sequencing showed 13 amino acid changes compared to reference sequences, including an N501T substitution in the spike protein, suggesting position 501 mutations were circulating in Italy by August 2020. Because N501Y mutations circulating in the United Kingdom may alter binding affinity, authors recommend surveillance for emerging variations in receptor-binding domain that may contribute to immune escape and viral spread.
Transmission & Prevention
· Infectious disease physicians from St George's Hospital in the United Kingdom analyzed samples from 66,001 patients who had PCR and/or a serological SARS-CoV-2 assay performed during the first wave of the COVID-19 pandemic (February to July 2020). They found patients who had evidence of SARS-CoV-2 infection via PCR or antibody during the first wave of the pandemic (n=10,727) had a significantly lower risk of a positive PCR during the second wave (August to December 2020) compared to those with no prior infection (RR 0.0578, 95%CI 0.0288-0.1160). The authors suggest prior infection with SARS-CoV-2 confers some protection against future infection and encourage further research to determine the duration of protection and explore strain-specific immunity.
· In this study, an interdisciplinary group of researchers report on phase 1-2a trial interum results of the candidate vaccine Ad26.COV2.S for COVID-19. These phases were to determine the safety and reactogenicity of the high dose schedule (given once) and low dose schedule (given twice) of the vaccine. The safety of the vaccine was determined by self-reported events characterized as either "adverse events" or "serious adverse events". Reactogenicity, was measured using an ELISA assay to detect for SARS-CoV-2 S-specific binding antibodies. The results of this study indicate that the vaccine has an acceptable safety and reactogenicity profile after a single vaccination with either the high or low dose. In addition, a single dose of the Ad26.COV2.S vaccine elicited a strong humoral response in a majority of vaccine patients (90%). This study offers promising data on a potential vaccine candidate by demonstrating its safety and efficacy in human subjects.
Management
· A systematic review conducted by Debre Tabor University in Ethiopia analyzed 9 articles published internationally from 2019 through September 2020 surrounding Vitamin D and COVID-19 outcomes and found 7 studies (77.8%) that demonstrated vitamin D deficiency correlated with increased likelihood of COVID-19 infection, need for hospitalization, disease severity, odds of ICU admission, and mortality. Although two studies included in this review found no association between Vitamin D levels and COVID-19 infection outcome, the corresponding authors attributed this to the timing of vitamin D sampling in the patients. Overall, authors suggest that these findings support maintaining appropriate Vitamin D levels for the general public through supplementation or sunlight exposure to improve COVID-19 outcomes.
R&D: Diagnosis & Treatments
· A prospective cohort study was conducted at three primary care centers by the Departments of Health and multiple hospitals in Alicante, Spain between September 15 and October 29, 2020 to assess the performance of RT-PCR saliva testing for COVID-19 through three different methods of collection on 577 patients who were either symptomatic or asymptomatic with known exposure to COVID-19 prior to receiving the gold standard comparator RT-PCR nasopharyngeal swab (NPS). Results showed that supervised collection (SVC) had the best performance with 86% sensitivity compared to 66.7% sensitivity of self-collected (SC) samples and a higher sensitivity was achieved when cycle threshold was low resulting in 100% sensitivity in symptomatic and 88.9% sensitivity in asymptomatic patients with RT-PCR. These findings suggest that saliva specimens perform comparably to the NPS samples and are considered effective for detection of SARS-CoV-2 in the community.
Resources
· An expert in health economics from the Frankfurt School of Finance and Management in Germany created a model to analyze the cost-effectiveness of expanding or maintaining intensive care unit (ICU) bed reserve capacity to prepare for a second wave of the COVID-19 pandemic. With full bed utilization, they found the last staffed bed added cost €21,958 per life-year gained with a positive return on investment. Net monetary benefit remained positive with utilization above 2%. The author concludes ICU bed expansion is cost effective even at a large vacancy rate and advocates for more cost-effectiveness analysis to improve hospital preparedness and determine appropriate capacity increases.
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