COVID variants of concern more virulent, study says
COVID-19 variants of concern (VOCs), especially the Delta (B1617.2) variant, are more virulent than the wild type, according to an Ontario-based study published in CMAJ yesterday. The cohort included 212,326 cases of non-VOCs (22.4%) and VOCs with the N501Y mutation (76.7%), such as Alpha (B117), Beta (B1351), Gamma (P1), and Delta.
The researchers found that the VOCs had a 52% increased risk of hospitalization (95% confidence interval [CI], 42% to 63%), 89% increased risk of intensive care unit (ICU) admission (95% CI, 67% to 117%), and a 51% increased risk of death (95% CI, 30% to 78%).
The Delta variant, although only 2.8% of the sample size, was associated with a 108% increased risk of infection (95% CI, 78% to 140%), a 235% increased risk of ICU admission (95% CI, 160% to 331%), and a 133% higher risk of death (95% CI, 54% to 231%).
Data also indicated that those infected by VOCs were significantly younger and less likely to have comorbidities compared with those infected with the wild-type virus.
“Canada is battling a different pandemic from the one it faced in early 2020,” writes Kirsten Patrick, MBBCh, MSc, in a related editorial. “The virus has become smarter and more dangerous, which means that we need to be smarter too. Canada’s governments can keep people safe by enacting policies that wisely combine all the measures that have been shown to be effective.”
Both Patrick and the researchers highlight the usefulness of the COVID-19 vaccines, with the researchers adding, “The effects reported here represent a substantial degree of protection against death conferred by vaccines (about 80%–90%), even when they fail to prevent infection. Such direct protective effects may help reduce the health impacts of ongoing SARS-CoV-2 transmission in Ontario, even if herd immunity proves elusive, given the high reproduction numbers of VOCs.”
The study included COVID-19 tests that took place Feb 7 to June 26. During that time, Delta was first detected in Canada in April, and by July, it was the predominant strain.
Oct 4 CMAJ study and editorial
Convalescent plasma didn’t help critical COVID-19 patients
Convalescent plasma didn’t help adults with critical COVID-19 have better outcomes, according to a randomized trial published yesterday in JAMA.
The 2,011-person study was rolled out at sites in the United Kingdom (115), Canada (9), Australia (4), and the United States (1, the only location that offered delayed convalescent plasma to 11 patients). The median age was 61 years, and 32.3% were women.
Almost 1,050 people received two units of high-titer, ABO-compatible convalescent plasma an average of 42.7 hours after hospital admission and 17.7 hours after ICU admission; 916 didn’t receive anything beyond the standard of care.
The median number of organ support-free days within the first 21 days was zero in the treatment group and 3 in the control group (odds ratio, 0.97). Overall mortality was lower in the treatment group (37.3% vs 38.4%), but serious adverse events were more common (3.0% vs 1.3%). The posterior probability of futility was 99.4% across the primary outcome of being organ support-free within 21 days.
“We speculate that [the futility] could be a combination of too few high-quality antibodies in the plasma and these patients being too far along in their illness with a run-away inflammatory immune response for those antibodies to turn the tide,” said co-senior author Derek Angus, MD, MPH, in a University of Pittsburgh press release. “It is still possible that convalescent plasma helps people in earlier stages of illness, though it is likely not efficient to use given that monoclonal antibodies … are such an effective treatment for early COVID-19.”
While the study was stopped Jan 15 for futility, the researchers noted that convalescent plasma appeared to help the 126 immunocompromised patients (posterior probability of superiority, 89.8%), unless it was given more than 7 days into their hospitalization (posterior probability of harm, 90.3%). However, the sample size was too small to draw any conclusions.
Oct 4 JAMA study
Oct 4 University of Pittsburgh press release
Excess pandemic deaths hit minorities harder, study says
Excess pandemic deaths in the United States were disproportionately higher in Black, American Indian/Alaska Native, and Latino people than in White and Asian people, according to a study today in the Annals of Internal Medicine.
The researchers used Centers for Disease Control and Prevention and US Census Bureau data to compare mortality per 100,000 people from March to December 2020 with the corresponding months in 2019. Excess deaths by racial population size were calculated under the assumption that the 2019 population sizes still held true.
During the 2020 study period, about 2.88 million people died, for an excess of 477,200 excess deaths compared with the 2019 period. About 74% of them were attributed to COVID-19, but Black, American Indian/Alaska Native, and Latino people had more than double the COVID-19 deaths per 100,000 people compared with White and Asian people.
Among non–COVID-19 deaths, Black and American Indian/Alaska Native people had three- to four-fold higher deaths per 100,000 people compared with White people, while Latinos had almost two-fold higher deaths.
Broken down by race, non–COVID-19 deaths were 22.6% of excess 2020 deaths among White people, 29.7% among Black people, 22.8% among Latino people, 25.8% among Asian people, and 30.9% among American Indian/Alaska Native people.
Data also showed that non–COVID-19 deaths were more prominent in those younger than 45 (75% of deaths vs 22% in those older), and racial disparities were more prevalent in those 75 years and older (eg, deaths per 100,000 people were nine times higher among Black men than among White men).
“It is possible that fear of seeking out health care during the pandemic or misattribution of causes of death from COVID-19 are responsible for a majority of the excess non–COVID-19 deaths,” said lead author Meredith S. Shiels, PhD, MHS, in a National Cancer Institute (NCI) press release.
The researchers note that American Indian/Alaska Native deaths may be underestimated, as this race is misclassified 40% of the time on death certificates.
Oct 5 Ann Intern Med study
Oct 4 NCI press release