July 12, 2021

Clinical Reports

Association Between Administration of IL-6 Antagonists and Mortality Among Patients Hospitalized for COVID-19
This meta-analysis determined the effect of administration of IL-6 antagonists with 28-day all-cause mortality in patients hospitalized for COVID-19. This prospective meta-analysis of 27 randomized trials included 10 930 patients, of whom 2565 died by 28 days. The 28-day all-cause mortality was lower among patients who received IL-6 antagonists compared with those who received usual care or placebo (summary odds ratio, 0.86). The summary odds ratios for the association of IL-6 antagonist treatment with 28-day all-cause mortality were 0.78 with concomitant administration of corticosteroids vs 1.09 without administration of corticosteroids. Administration of IL-6 antagonists, compared with usual care or placebo, was associated with lower 28-day all-cause mortality in patients hospitalized for COVID-19.

The Impact of COVID Vaccination on Symptoms of Long COVID. An International Survey of People with Lived Experience of Long COVID
Long COVID is a multi-system syndrome following SARS-COV-2 infection with persistent symptoms of at least 4 weeks, and frequently for several months. It has been suggested that there may be an autoimmune component.  There has been an understandable caution amongst those experiencing long COVID given the potential impact of vaccination on boosting immune response. This survey of people living with Long COVID evaluated the impact of their first dose vaccination on their symptoms.  Patients with Long COVID were invited to complete a web-based questionnaire through postings on social media and direct mailing from support groups. Basic demographics, range, and severity of Long COVID symptoms, which vaccine received, and impact of vaccine were collated. 900 people participated in the questionnaire, of whom 45 had pre-existing myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS) but no evidence of COVID infection, and a further 43 did not complete the survey in full. The demographics and symptomology of the remaining 812 people were similar to the Office of National Statistics. Following vaccination, 57.9% of participants reported improvements in symptoms, 17.9% reported deterioration, and the remainder no change. There was considerable individual variation in responses. Larger improvements in symptom severity scores were seen in those receiving the mRNA vaccines compared to adenoviral vector vaccines. This survey suggests COVID-19 vaccination may improve long COVID patients on average. The observational nature of the survey limits drawing direct causal inference but demands validation with a randomized controlled trial.

Antiviral Therapeutics and Vaccines

Ad26.COV2.S elicited neutralizing activity against Delta and other SARS-CoV-2 variants of concern
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to evolve and recently emerging variants with substitutions in the Spike protein have led to growing concerns over increased transmissibility and decreased vaccine coverage due to immune evasion. Here, sera from recipients of a single dose of our Ad26.COV2.S COVID-19 vaccine were tested for neutralizing activity against several SARS-CoV-2 variants of concern. All tested variants demonstrated susceptibility to Ad26.COV2.S-induced serum neutralization albeit mainly reduced as compared to the B.1 strain. The most pronounced reduction was observed for the B.1.351 (Beta; 3.6-fold) and P.1 (Gamma; 3.4-fold) variants that contain similar mutations in the receptor-binding domain (RBD) while only a 1.6-fold reduction was observed for the widely spreading B.1.617.2 (Delta) variant.

Prevention and Attenuation of Covid-19 with the BNT162b2 and mRNA-1273 Vaccines
The authors conducted a prospective cohort study involving 3975 health care personnel, first responders, and other essential and frontline workers. From December 14, 2020, to April 10, 2021, the participants completed weekly SARS-CoV-2 testing by providing mid-turbinate nasal swabs for qualitative and quantitative reverse-transcriptase–polymerase-chain-reaction (RT-PCR) analysis. The formula for calculating vaccine effectiveness was 100%×(1−hazard ratio for SARS-CoV-2 infection in vaccinated vs. unvaccinated participants), with adjustments for the propensity to be vaccinated, study site, occupation, and local viral circulation. SARS-CoV-2 was detected in 204 participants (5%), of whom 5 were fully vaccinated (≥14 days after dose 2), 11 partially vaccinated (≥14 days after dose 1 and <14 days after dose 2), and 156 unvaccinated; the 32 participants with indeterminate vaccination status (<14 days after dose 1) were excluded. Adjusted vaccine effectiveness was 91% (95% confidence interval [CI], 76 to 97) with full vaccination and 81% (95% CI, 64 to 90) with partial vaccination. Among participants with SARS-CoV-2 infection, the mean viral RNA load was 40% lower (95% CI, 16 to 57) in partially or fully vaccinated participants than in unvaccinated participants. In addition, the risk of febrile symptoms was 58% lower (relative risk, 0.42; 95% CI, 0.18 to 0.98) and the duration of illness was shorter, with 2.3 fewer days spent sick in bed (95% CI, 0.8 to 3.7). Authorized mRNA vaccines were highly effective among working-age adults in preventing SARS-CoV-2 infection when administered in real-world conditions, and the vaccines attenuated the viral RNA load, risk of febrile symptoms, and duration of illness among those who had breakthrough infection despite vaccination. 

Ivermectin to prevent hospitalizations in patients with COVID-19 (IVERCOR-COVID19) a randomized, double-blind, placebo-controlled trial
The purpose of this study was to determine whether ivermectin treatment can prevent hospitalization in individuals with early COVID-19. A randomized, double-blind, placebo-controlled study was conducted in non-hospitalized individuals with COVID-19 in Corrientes, Argentina. Patients with SARS-CoV-2 positive nasal swabs were contacted within 48 h by telephone to invite them to participate. The trial randomized 501 patients between August 19th, 2020 and February 22nd, 2021. Patients were randomized to ivermectin (N = 250) or placebo (N = 251) arms in a staggered dose, according to the patient’s weight, for 2 days. The efficacy of ivermectin to prevent hospitalizations was evaluated as the primary outcome. Secondary outcomes were evaluated in relation to safety and other efficacy endpoints. The mean age was 42 years (SD ± 15.5) and the median time from symptom onset to the inclusion was 4 days [interquartile range 3–6]. The primary outcome of hospitalization was met in 14/250 (5.6%) individuals in ivermectin group and 21/251 (8.4%) in placebo group (odds ratio 0.65; 95% confidence interval, 0.32–1.31; p = 0.227). Time to hospitalization was not statistically different between groups. The mean time from study enrollment to invasive mechanical ventilatory support (MVS) was 5.25 days (SD ± 1.71) in the ivermectin group and 10 days (SD ± 2) in the placebo group, (p = 0.019). There were no statistically significant differences in the other secondary outcomes including polymerase chain reaction test negativity and safety outcomes. Ivermectin had no significant effect on preventing hospitalization of patients with COVID-19. Patients who received ivermectin required invasive MVS earlier in their treatment. No significant differences were observed in any of the other secondary outcomes.

Environmental Studies

Efficacy of Portable Air Cleaners and Masking for Reducing Indoor Exposure to Simulated Exhaled SARS-CoV-2 Aerosols — United States, 2021
Ventilation systems can be supplemented with portable high efficiency particulate air (HEPA) cleaners to reduce the number of airborne infectious particles. A simulated infected meeting participant who was exhaling aerosols was placed in a room with two simulated uninfected participants and a simulated uninfected speaker. Using two HEPA air cleaners close to the aerosol source reduced the aerosol exposure of the uninfected participants and speaker by up to 65%. A combination of HEPA air cleaners and universal masking reduced exposure by up to 90%. Portable HEPA air cleaners can reduce exposure to simulated SARS-CoV-2 aerosols in indoor environments, especially when combined with universal masking.

Situation Dashboards


World Health Organization (WHO)

Novel Coronavirus (COVID-19) Situation from World Health Organization (WHO)

Johns Hopkins University (JHU)

Coronavirus COVID-19 Global Cases by the Center for Systems Science and Engineering (CSSE) at JHU

COVID-19 in US and Canada

1Point3Acres Real-Time Coronavirus (COVID-19) Updates in US and Canada with Credible Sources

Genomic Epidemiology COVID-19

Genomic Epidemiology of (COVID-19) Maintained by the Nextstrain team, enabled by data from GISAID.

Sources for COVID-19 Information


World Health Organization (WHO)


Centers for Disease Control, US


International Society for Infectious Diseases


This Week in Virology (TWIV)

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