New monoclonal antibody sharply reduces risk of severe COVID outcomes
The monoclonal antibody sotrovimab reduced the risk of hospitalization or death from COVID-19 by 85% compared with placebo, according to an interim analysis of a phase 3 clinical trial published yesterday in the New England Journal of Medicine.
In the double-blind, multicenter trial, non-hospitalized patients with symptomatic COVID-19 and at least one risk factor for disease progression were randomly assigned to receive either 500 milligrams of sotrovimab, a pan-sarbecovirus monoclonal antibody developed by GlaxoSmithKline and Vir Biotechnology, or placebo. Patients were recruited from Aug 27, 2020, and followed through Mar 4, 2021, and more than 60% were Hispanic or Latino—a population the investigators note has been underrepresented in COVID-19 clinical trials.
The primary outcome was the percentage of patients who were hospitalized for more than 24 hours or who died from any cause through 29 days after randomization.
Among the 583 patients included in the intention-to-treat population (291 in the sotrovimab group and 292 in the placebo group), 3 patients treated with sotrovimab (1%) had disease progression leading to hospitalization or death, compared with 21 patients (7%) in the placebo group (relative risk reduction, 85%; 97.24% confidence interval [CI], 44% to 96%). All 5 patients who were admitted to the intensive care unit were in the placebo group, as were 2 of the 5 received invasive mechanical ventilation.
Among the 868 patients in the safety population, adverse events were reported by 17% of patients in the sotrovimab group and 19% of the placebo group. Serious adverse events occurred in 2% of patients who received sotrovimab, compared with 6% of patients who received placebo.
The study authors note that sotrovimab was selected to have an intrinsically higher barrier to resistance as a result of targeting a pan-sarbecovirus epitope, which means it could remain effective against future coronavirus variants.
"Given its in vitro activity against variants of interest and concern, as well as its ability to neutralize other sarbecoviruses, we speculate that sotrovimab has the potential to remain therapeutically active even as SARS-CoV-2 continues to evolve," they wrote.
Oct 27 N Engl J Med study
Study highlights waning protection of Pfizer COVID vaccine against Delta
In another study published yesterday in the New England Journal of Medicine, Israeli researchers reported further evidence of waning effectiveness of the Pfizer/BioNTech COVID-19 vaccine against the more transmissible Delta (B1617.2) variant.
To estimate the role of waning immunity in breakthrough infections during Israel's summer wave of Delta variant infections, researchers collected data on confirmed SARS-CoV-2 infections and severe disease reported from Jul 11 to 31 among all Israeli residents who had been vaccinated with the Pfizer vaccine prior to June. They then compared rates of infection and severe COVID-19 among people vaccinated during different periods, with stratification according to age-group and adjustment for possible confounding factors.
Among more than 4.7 million fully vaccinated adults, 13,426 had confirmed SARS-CoV-2 and 403 had severe COVID-19. The rate of confirmed infection showed a clear increase as the time from vaccination increased for all age-groups. Among people age 60 and older, the rate of infection from Jul 11 to 31 was higher for those who were fully vaccinated in January 2021 than for those vaccinated in March 2021 (rate ratio, 1.6; 95% CI, 1.3 to 2.0). Among people ages 40 to 59, the rate of infection was 1.7 (95% CI, 1.4 to 2.1) times higher for those fully vaccinated in February compared with those fully vaccinated in April. For the age 16-to-39 group, the rate of infection was 1.6 (95% CI, 1.3 to 2.0) times higher for those fully vaccinated in March compared with those vaccinated in May.
The results were similar for severe COVID-19. Among fully vaccinated people ages 60 and older and 40 to 59, the rate ratios for severe disease were 1.8 (95% CI, 1.1 to 2.9) and 2.2 (95% CI, 0.6 to 7.7), respectively, for those fully vaccinated in January or February compared with those vaccinated in March. The rate ratio could not be calculated for those ages 16 to 39, given the small number of severe cases in this group.
The study authors say the findings provide an epidemiologic basis for the Israeli government's decision to approve booster shots in July for those who had been vaccinated at least 5 months previously. "The findings also suggest the need to follow the effects of waning immunity closely and to inform policymakers worldwide who are facing decisions regarding the administration of booster vaccinations," they wrote.
Oct 27 N Engl J Med study
Committee: Meatpackers' COVID-19 cases much higher than reported
A congressional committee's examination of documents from five of the nation's biggest meatpacking companies found that at least 59,000 meatpacking workers contracted COVID-19 and 269 died in the first year of the pandemic, almost triple the 22,700 cases previously estimated for the five firms by the Food and Environment Reporting Network.
The report is based on documents from JBS, Tyson Foods, Smithfield Foods, Cargill, and National Beef. Together the companies control over 80% of the beef market and over 60% of the pork market.
The 59,000 cases may even be an undercount. "Because data for Smithfield, Tyson, and National Beef may exclude positive coronavirus tests from community testing centers or other health providers, it is likely that the actual rate of coronavirus infections among these companies' workers was even higher than these companies' data reflects," the report says.
Several of the documents shared with the committee offered new information on dangerous working conditions, including sweat-saturated masks and flimsy plastic partitions between workers.
The committee's report included several examples of hot spot meatpacking plants, including a Tyson plant in Amarillo, Texas, where 49.8% of workers contracted the virus, and five people died. Other hot spots included a JBS plant in Hyrum, Utah, where 54% of the workforce contracted the virus, and National Beef’s plant in Tama, Iowa, where 44% of employees got the virus.
Oct 27 committee report