Convalescent plasma didn't prevent severe COVID-19 in high-risk patients
Early use of convalescent plasma didn't prevent COVID-19 progression in a group of high-risk adult outpatients, concludes a National Institutes of Health (NIH) study yesterday in the New England Journal of Medicine (NEJM).
The randomized, controlled Clinical Trial of COVID-19 Convalescent Plasma in Outpatients (C3PO) trial enrolled more than 500 participants who visited 1 of 48 US emergency departments within 7 days of COVID-19 symptom onset. Enrollees were 50 and older and had one or more risk factors for severe COVID-19 (eg, obesity, high blood pressure, diabetes, heart disease, chronic lung disease).
The participants were assigned to receive either one unit (250 milliliters) of convalescent plasma with high concentrations of anti–SARS-CoV-2 antibodies or a placebo. Antibody-rich convalescent plasma from COVID-19 survivors was given Food and Drug Administration emergency authorization in 2020 for use in hospitalized coronavirus patients.
There was no significant difference between the two groups of patients in disease progression (ie, need to seek further emergency or urgent care, hospital admission, or death) in the 15 days after treatment. Among the 511 participants, 30% in the convalescent plasma group and 31.9% in the placebo group experienced disease progression. Illness severity and days out of the hospital were similar in both groups.
Five patients who received convalescent plasma and one given a placebo died. The trial was stopped on Feb 25, 2021, after an interim analysis revealed futility.
Study principal investigator Clifton Callaway, MD, PhD, of the University of Pittsburgh, said in an NIH news release that the researchers were disappointed by the 1.9-percentage-point disease progression reduction when they had hoped for at least 10 percentage points. "That was surprising to us," he said. "As physicians, we wanted this to make a big difference in reducing severe illness, and it did not."
But the researchers said that there could still be a role for convalescent plasma in COVID-19 if it is given before development of native antibodies. "The treatment may also be efficacious in preventing symptomatic Covid-19 after exposure," they wrote. "This trial was designed to detect an absolute risk difference of 10 percentage points in disease progression. However, we cannot exclude smaller effect sizes with less clinical importance."
Aug 18 NEJM study
Aug 18 NIH news release
COVID-19 Facebook ads may have deterred holiday travel
Facebook videos of healthcare providers encouraging people to stay home for the 2020 holidays were associated with a 3.5% decrease in county-level cases, according to a study today in Nature Medicine.
The researchers had physicians and nurses create 20-second videos on their smartphones and presented them as sponsored content to 75% of Facebook users in high-intensity COVID-19 counties and 25% of low-intensity COVID-19 counties before Thanksgiving and before Christmas last year. Recipients were randomized by zip code, and, on average, each user in a treatment zip code received 2.6 videos at Thanksgiving and 3.5 at Christmas.
During the Thanksgiving campaign, distance traveled away from home declined more in high-intensity counties than in low-intensity counties 3 days before the holiday, and for Christmas, the same findings occurred on Dec 21 and 22, 2020. Overall, the average distance decreased by -0.99 percentage points in high-intensity counties 3 days before each holiday compared with low-intensity counties (95% confidence interval [CI], -1.62 to -0.37; baseline, February 2020). The researchers note, however, that the same proportion of people traveled on the day of each holiday.
In the 2-week period 5 days after the holiday, COVID-19 infections declined 3.5% in intervention zip codes versus control zip codes within counties (adjusted 95% CI, -6.2% to -0.7%).
"There was no significant difference between intervention and comparison zip codes in any pre-intervention period, making it very unlikely that the difference in COVID-19 cases was due to random chance," the researchers write. "In addition, the effect seems to be concentrated in the 2 weeks immediately after the holiday, especially for Christmas, suggesting that the effects were not persistent."
The study included 6,998 zip codes and 11,954,109 users, with 820 counties in the Thanksgiving campaign and 767 included in the Christmas campaign. Travel was tracked via social media data.
Aug 19 Nat Med study
Initial sequencing, travel history yield clues in Ivory Coast Ebola case
An early analysis of the Ebola virus from Ivory Coast's recent imported Ebola case suggests ties to the virus that circulated in West Africa's massive outbreak in 2014 to 2016, the World Health Organization (WHO) regional office for Africa said in its weekly outbreaks and health emergencies update.
The 18-year-old Guinea woman's illness was detected in the Ivory Coast the day after she arrived in the city of Abidjan. Preliminary sequencing results suggest that the virus is closely related to the virus involved in West Africa's 2014-16 outbreak, the WHO said. Guinea's most recent outbreak, declared over in the middle of June, was thought to be linked to a survivor of the 2014-2016 outbreak. That finding raised the possibility that humans may harbor the virus in protected immune sites much longer than previously thought.
Also, the WHO's update provided fresh details about the route that the woman took to travel from Labe, in Guinea's northwest, to Ivory Coast. It said she traveled through N'zerekore, the region in the southeast that recently experienced an Ebola outbreak and recently reported a Marburg fever case. She boarded public transport there, which took her into Ivory Coast.
The woman's symptoms began while en route and she self-medicated with acetaminophen. She sought care at a local clinic when she arrived in Ivory Coast.
The WHO said the woman could have been exposed before she departed or during the trip, raising the possibility of undetected transmission chains in the area. The group noted a second suspected case, in a family contact, is under monitoring, with confirmation tests pending.
Aug 16 WHO African regional office weekly report
Aug 16 CIDRAP News story "Source of Ivory Coast Ebola case probed"
China reports another H5N6 avian flu patient, husband of earlier case
China reported another H5N6 avian flu case, which involves the 54-year-old husband of a 55-year-old woman who was recently hospitalized with the same disease.
Both had shopped at a live-animal market and had cooked and eaten a duck bought at the market, Hong Kong's Centre for Health Protection (CHP) said in a statement today.
The couple are from Chenzhou City in Hunan province. The CHP announced the woman's illness last week, noting that she was hospitalized and in serious condition.
In the statement today, the CHP said the man's symptoms began on Aug 2, and he was admitted to the hospital for treatment the same day, where he is in stable condition. The interval between their symptom onsets is 7 days.
China has now reported 15 H5N6 cases this year, signaling an uptick in infections involving the strain. The virus is known to circulate in poultry, mainly in Asian countries. However, China and Laos are the only countries to report human cases, which are typically severe or fatal. The first human cases were identified in 2014, and since then, China has reported 39 cases.
Aug 19 CHP statement
Aug 11 CIDRAP News scan