mRNA COVID vaccines highly effective against Delta hospitalization, death

Two doses of the Pfizer/BioNTech and Moderna mRNA COVID-19 vaccines were 93% and 96% effective, respectively, in preventing severe, critical, or fatal disease caused by the highly transmissible Delta (B1617.2) variant, a study today in Nature Medicine finds.

Researchers in Qatar evaluated the vaccines' effectiveness in residents from Mar 23 to Sep 7, 2021, a period in which 43% of COVID-19 cases were attributed to Delta. Over 80% of Qataris were estimated to have been fully vaccinated by Sep 19.

During the study period, 88 and 1,126 Delta breakthrough infections and 4 and 15 cases requiring hospitalization occurred among residents vaccinated with one or two Pfizer vaccine doses, respectively. For Moderna, the researchers logged 60 and 187 breakthrough infections and 3 and 1 severe cases, respectively.

Delta infections requiring intensive care were reported in one and two Pfizer vaccinees who received one or two doses, respectively; the patient who received one dose died. There were no critical or fatal infections reported among Moderna vaccinees.

Vaccine effectiveness against Delta infection 14 or more days after the first dose was estimated at 45.3% (95% confidence interval [CI], 22.0% to 61.6%) in the Pfizer group, 73.7% (95% CI, 58.1% to 83.5%) in the Moderna group, and 58.0% (95% CI, 44.4% to 68.2%) for either vaccine.

Fourteen or more days after the second dose, effectiveness against Delta infection was 51.9% (95% CI, 47.0% to 56.4%) for Pfizer, 73.1% (95% CI, 67.5% to 77.8%) for Moderna, and 55.5% (95% CI, 51.2% to 59.4%) for either vaccine.

Effectiveness against severe, critical, or fatal Delta COVID-19 disease after the second dose was 93.4% (95% CI, 85.4% to 97.0%) for Pfizer, 96.1% (95% CI, 71.6% to 99.5%) for Moderna, and 93.6% (95% CI, 85.9% to 97.1%) for either vaccine.

"These findings indicate the need for more follow-up of vaccinated cohorts to investigate waning of vaccine immunity," the researchers concluded.
Nov 2 Nat Med study

Study shows increased screen time for teens during COVID-19 pandemic

JAMA Pediatrics published a new study yesterday highlighting increased screen time among teens during the pandemic, showing that daily hours spent on devices doubled during the first months of COVID-19.

Researchers from the University of California-San Francisco (UCSF) found that young teens in the United States averaged 7.7 hours a day on screens, excluding school work, in May 2020, compared to 3.8 hours a day before the pandemic. The data was self-reported from 5,412 adolescents ages 12 to 13 years who are taking part in the Adolescent Brain Cognitive Development (ABCD) longitudinal study.

Excessive screen time during the pandemic has been linked to worsening health outcomes for American children, including weight gain and depression.

"As screen time increased, so did adolescents' worry and stress, while their coping abilities declined," lead author Jason Nagata, MD, said in a university press release. "Though social media and video chat can foster social connection and support, we found that most of the adolescents' screen use during the pandemic didn't serve this purpose."

Researchers found that Black and Latino teens were also more likely to report increased screen time than White peers.

"Screen time disparities across racial, ethnic, and income groups in adolescents have been reported previously and may be due to structural and systemic racism–driven factors (eg, built environment, access to financial resources, and digital media education)—all of which have been amplified in the COVID-19 pandemic," the authors wrote.
Nov 1 JAMA Pediatr study
Nov 1 UCSF press release

Chronic wasting disease detected for first time in Manitoba

Officials in Manitoba announced yesterday that chronic wasting disease (CWD) was detected for the first time in the province, in a wild male mule deer near Lake of the Prairies.

The animal was observed to be unwell in mid-October, and it was euthanized and CWD testing was performed. In response to the detection, the province announced an immediate ban on hunting deer, moose, caribou, and elk in the area.

"Manitoba has had very rigorous reporting and testing requirements for CWD, including making it illegal to bring certain unprocessed meat into Manitoba," the Manitoba government said in a press release. CWD has been confirmed in wild and captive cervids in Saskatchewan and Alberta and in captive cervids in Quebec province.

CWD is a fatal prion disease that affects cervids like deer, elk, and moose. The disease was first detected in wild deer in the United States in 1981 and has now been detected in 26 states, and implications for human health are still unknown. Manitoba said there is no evidence at this time that the disease has spread to the province's elk farms.
Nov 1 Manitoba press release

Cases and deaths rise in DRC's latest Ebola outbreak: 8 cases, 6 deaths

Two more Ebola cases have been reported in the Democratic Republic of the Congo's (DRC's) latest flare-up, with the illnesses reported in two more health districts, signaling an expansion of the outbreak, the World Health Organization (WHO) African regional office said today.

In its weekly outbreaks and health emergencies report, the WHO said that, so far, eight cases have been confirmed, and three more deaths were reported, raising the fatality count to six.

The two new cases were reported from Bundji and Ngilinga health areas; whereas, the earlier six cases were all reported from Butsili health area. All three are located in Beni health zone. The WHO said the spread to other health areas is concerning.

Also, one of the latest deaths occurred in the community, which the agency said is also worrisome because of the risk of further spread. So far, 394 people have been vaccinated, and, of 551 contacts who have been identified, 448 are under active monitoring.

The outbreak is the DRC's 13th. The initial case involved a young boy whose fatal infection was confirmed following the suspicious deaths of three of his neighbors. Initial sequencing results suggest that the cases are linked to a large outbreak that occurred across a wide area centered in North Kivu province from 2018 to 2020.
Nov 2 WHO African regional office weekly report

China's H5N6 avian flu case uptick prompts new CDC risk assessment

The doubling of human H5N6 avian flu cases in China this year is raising concerns about the strain's pandemic potential, and the US Centers for Disease Control and Prevention (CDC) said yesterday that a new risk assessment is under way.

In a statement, the CDC said its earlier risk assessment in 2016 put the risk as moderate, both in its potential to trigger a pandemic and its potential to cause a moderate public health impact if human-to-human transmission were to occur. Since then, multiple candidate vaccine viruses against H5 strains have been developed to cover various antigenic groups, it added.

Tests on the H5N6 viruses suggest that they are still susceptible to antiviral treatments such as neuraminidase inhibitors like oseltamivir (Tamiflu) and to the polymerase acidic protein inhibitor baloxavir.

Since 2014, when H5N6 was first detected in humans, 51 cases have been reported, including 25 in 2021 as of Oct 29. Since then, China has reported 2 more, raising this year's total to 27. All but one of the cases has been reported in China. Earlier this year, Laos reported its first H5N6 infection.

Of the 51 cases reported to the WHO since 2014, 25 were fatal. The CDC added that H5N6 was first found in poultry in 2013 and that it continues to spread among wild birds and poultry. Though sporadic human infections are expected, the CDC said the situation bears close monitoring due to the possibility that the virus could change and spread more easily among people. So far, most cases have occurred in people who had contact with poultry or poultry environments.
Nov 1 CDC statement