Three quarters of US high school students didn’t get enough sleep, and two-thirds had difficulty completing schoolwork, in 2021 amid the pandemic, according to a survey study published late last week in Preventing Chronic Disease.

Researchers at the Centers for Disease Control and Prevention (CDC) analyzed Adolescent Behaviors and Experiences Survey data collected from 7,705 students in grades 9 to 12 from January to June 2021.

The American Academy of Sleep Medicine recommends that adolescents aged 13 to 18 sleep 8 to 10 hours a night. “Short sleep duration among adolescents is linked to higher risk of injury, worse metabolic and mental health, and difficulty focusing,” the researchers wrote.

Poor mental health in 37%

Most respondents (76.5%) reported sleeping for an average of less than 8 hours per school night, and 66.6% said they struggled more with schoolwork than they did before the pandemic.

Teens who slept less than 7 hours per school night were 17% more likely to report difficulty with schoolwork than those who slept 8 to 10 hours (Pearson correlation r [PR] for 6 hours of sleep relative to at least 8 hours, 1.17; 5 hours, 1.18; 4 or fewer hours, 1.20).

“The unadjusted models confirmed the hypothesized association between short sleep duration and greater difficulty doing schoolwork, which remained robust after adjusting for covariates,” the researchers wrote.

A total of 37.1% of teens reported poor mental health, which correlated with inadequate sleep (PR, 0.22). Fewer students who slept at least 8 hours a night (25.2%) reported poor mental health, while 49.1% of those who slept 5 hours or less each night and 55.9% who slept less than 4 hours said their mental health was poor.

Students who reported poor mental health were 17% more likely to say they had difficulty doing schoolwork than those who didn’t report mental health challenges. Poor mental health didn’t mitigate the link between inadequate sleep and problems completing schoolwork.

A total of 37.1% of teens reported poor mental health, which correlated with inadequate sleep.

Respondents who spent 5 or more hours of daily screen time had a slightly lower likelihood of reporting more difficulty doing schoolwork than those who had less screen time (PR, 0.95). In the adjusted analysis, sex, grade, and hunger status weren’t tied to difficulty doing schoolwork, but Hispanic students were more likely than their White peers to report academic struggles.

Later school start times may help

The researchers cautioned that they couldn’t assess sleep quality or account for potential confounding factors such as socioeconomic status or whether school attendance was in-person, online, or a hybrid of the two.

“The latter may have influenced wake times and sleep duration, even if school start times were unchanged,” they wrote. “Instruction modality may also have influenced self-reported screen time; the question excludes time doing schoolwork but does not specify whether to count time using screens to attend school. This may help explain the counterintuitive finding that a high level of screen time was inversely associated with greater difficulty doing schoolwork.” 

The authors said that, even before the pandemic, shorter sleep duration was becoming more common among US high school students, at 77.9% in 2019, up from 74.6% in 2017.

“Teachers have identified behavioral and mental health challenges among the leading barriers to addressing learning gaps during the 2022–2023 school year,” they wrote. “Policies known to improve sleep duration among students, including later school start times and family practices, such as good sleep habits and parent-set bedtimes, might help support both learning and mental health.”

A Vanderbilt University study estimates that Americans took 719 fewer daily steps in the first year of the COVID-19 pandemic than they did before.

In the study, published yesterday in JAMA Network Open, researchers analyzed data from 5,443 All of Us (AOU) research participants with Fitbit tracking information for 10 days or more a month for at least 6 months before (January 2018 to January 2020) and after (June 2020 to December 2021) the pandemic began.

Participants also completed a survey on socioeconomic status, mental health, location, and deprivation index. Median age was 53 years, 71.7% were women, 86.0% were White, 9.3% were of other race, and 4.7% were Black.

Highest risk among poor, mentally ill

Median observed daily steps before the pandemic were 7,808, compared with 7,089 after (difference, 719 steps). A counterfactual model estimated that participants walked 575 fewer steps per day than the observed steps in 2021. The reduction was largely explained by younger age (β, −243 per 10-year decrease), residence in the Northeast (β vs other regions, −288), and higher deprivation index score (β, −477 per 0.1 increment).

Lower step counts in 2021 were also influenced by COVID-19 vaccination status (β for vaccinated vs unvaccinated, 48), depression (β, −36 per 1 score increment), and psychological stress (β, −13 per 1 score increment). There was no link between lower step counts and sex or chronic conditions such as obesity, diabetes, coronary artery disease, high blood pressure, or cancer.

“We found a statistically significant decline in daily step counts that persisted even after most COVID-19–related restrictions were relaxed, suggesting COVID-19 affected long-term behavioral choices,” the authors wrote.

But they said it’s unclear whether the reduction will be clinically meaningful over time. “Any meaningful difference is likely dependent on baseline activity, age, and other patient-level factors,” they wrote. “Our prior work in the AOU cohort suggests that modestly lower step counts over a long period could have a substantial contribution to long-term disease risk,” including the risk of cardiometabolic conditions and the potential to worsen health disparities associated with socioeconomic status and mental illness.

In two major developments regarding investigations into the source of SARS-CoV-2, an international research group that examined genetic sequences from the animal market detailed their findings in a new report, and President Joe Biden signed a bill to declassify US intelligence on virus origins.

Analysis details animal evidence in sequences, market

Authors of the report, posted on a preprint server, examined genetic sequences collected at the Huanan Seafood Market in Wuhan, China, that appeared earlier this month on GISAID before access to them was restricted. Chinese researchers had described their initial findings based on sequencing in a 2022 preprint but plan on publishing a fuller report in Nature.

The researchers who saw the sequences notified the World Health Organization (WHO), which last week convened discussions between its novel pathogens advisory group, international researchers who analyzed the sequences they downloaded, and the authors from the Chinese Center for Disease Control and Prevention (China CDC).

The earlier preprint from Chinese researchers suggested that the market may have amplified an already established epidemic. However, the international group said it found evidence of multiple animal species where positive SARS-CoV-2 environmental samples were found, including some that weren’t included on an earlier list of live or dead animals tested at the market.

“Our results show that they were present,” the group wrote. “In some cases, the amount of animal genetic material was greater than the amount of human genetic material, consistent with the presence of SARS-CoV-2 in these samples being due to animal infections.”

They said Chinese researchers had recently cleared the group to do an independent analysis but pulled access to the sequences on GISAID when researchers told them they found animal genetic material in the sequences. (In a new development today, GISAID released a statement raising concerns about whether the international group followed its access agreement and if they made their best efforts at collaborating with the group that contributed the sequences.)

The international group wrote that co-occurrence of SARS-CoV2 and genetic material of susceptible wildlife in the environmental samples at the start of the pandemic bolsters reports that potential intermediate animal hosts were for sale at the market in 2019. They said the findings add another piece of evidence that the site may have been the spillover location.

The strongest evidence was found for raccoon dogs, Amur hedgehogs, Malayan porcupines, hoary bamboo rats, and masked palm civets. They wrote that raccoon dogs are notable, because they are susceptible to productive SARS-CoV-2 infection, shed high volumes of virus, and can transmit to other susceptible animals. However, they said some samples align with other species known to be susceptible.

Genomic data confirming wildlife species were found in the same market stalls where some of the animals were sold. Some SARS-CoV-2 samples that contained human DNA, hinting at virus was also shed by infected people.

They concluded that their findings contribute to a large body of evidence pointing to a natural SARS-CoV-2 origin.

Bill orders declassification within 90 days

In another key development yesterday evening, the White House announced that President Biden signed the COVID-19 Origin Act of 2023, which would declassify as much intelligence information gleaned from US agencies as possible without hurting national security.

In a statement, Biden reiterated that in 2021, he directed the intelligence community to use all tools available to probe the origin of SARS-CoV-2.

Two US agencies—the Department of Energy and the Federal Bureau of Investigation—have said the virus likely came from a lab, but with low-confidence assessments. Other US intelligence groups have leaned toward a natural origin, also based on low-confidence assessments.

“We need to get to the bottom of COVID-19’s origins to help ensure we can better prevent future pandemics,” Biden said.

The law orders the Director of National Intelligence to declassify the information within 90 days, specifically that related to the work at the Wuhan Institute of Virology and illnesses of scientists who worked there and got sick in fall 2019.

COVID-19 cases and deaths continue downward trends, but with some regional differences, the World Health Organization (WHO) said today in its latest weekly update. Also, the group unveiled changes in its variant tracking system, which better defines sublineage circulation and identifies that ones that could prompt major public health actions.

Some nations see rises as XBB.1.5 rates climb

Over the past 28 days, COVID-19 cases declined 40% and deaths dropped 57% compared to the last 4-week period, the WHO said.

Cases were up modestly, however, in Europe, the Middle East, and India. In Europe, Russia, Germany, and Austria were among the countries reporting rising cases, while rises in the Mideast were partly driven by activity in Iran, and to a lesser extent, the United Arab Emirates. And India reported a spike in cases.

Regarding variant activity, the WHO said proportions of XBB and its related sublineages, including XBB.1.5, continue to rise and are now dominant in all regions except for the Western Pacific. It said there are 25 descendent XBB lineages, 3 of which show a growth advantage: XBB.1.5, XBB.1.9 and XBB.1.9.1.

Updated variant tracking

In a separate statement today, the WHO said it has tweaked its variant reporting to better reflect the current landscape, independently evaluate the Omicron sublineages that are circulating, and clarify new variants when needed.

It said Omicron viruses continue to evolve, expanding into multiple sublineages and accounting for 98% of sequences since February 2022. Though new SARS-CoV-2 variants will likely stem from Omicron, the WHO emphasized that the emergence of new variants from earlier variants of concern or completely new variants are still possible.

The group said the way it had been classifying Omicron variants didn’t clearly distinguish among them. So, as of yesterday, it will consider Omicron sublineages independently as variants under monitoring (VUM), variants of interest (VOI), or variants of concern (VOC). The Omicron parent lineage is classified as a VOC, but XBB.1.5 is classified as a VOI.

WHO emphasizes that these changes do not imply that the circulation of Omicron viruses no longer pose a threat to public health.

“WHO emphasizes that these changes do not imply that the circulation of Omicron viruses no longer pose a threat to public health,” it said. “Rather, the changes have been made in order to better identify additional or new threats over and above those posed by the current Omicron viruses in circulation.”

Also, the WHO said it is updating is definitions of VOCs and VOIs to make the one for VOC more specific to cover major SARS-CoV-2 evolutionary steps that require major public health interventions. It said going forward that Greek labels will be assigned only for VOCs.

The antiviral drug combination nirmatrelvir–ritonavir (Paxlovid) was estimated to be 54% effective against SARS-CoV-2 Omicron BA.2, BA.4, and BA.5 hospitalization or death but was 80% when taken within 5 days of symptom onset, according to an observational study published yesterday in The Lancet Infectious Diseases.

Paxlovid, an oral drug, is authorized for the treatment of COVID-19 patients aged 12 years and older at high risk for severe illness.

Researchers from the University of California at Berkeley and Paxlovid maker Pfizer led an analysis of the electronic health records of nonhospitalized patients aged 12 and older who tested positive for COVID-19 from April 8 to October 7, 2022, at Kaiser Permanente Southern California. Overall, 86% had received at least two doses of COVID-19 vaccine, and 61% had received at least three.

The study generated the first observational data that included the timing of symptom onset. A total of 12,574 patients received Paxlovid at any time during their illness, 10,038 Paxlovid recipients were tested within 5 days of symptom onset, 1,755 were tested after that timeframe, and 781 didn’t have COVID-19 symptoms at the point of testing.

90% effective when given on day of test

Hospitalization or death within 30 days occurred in 51 (0.7%) of Paxlovid recipients and 695 (0.6%) nonrecipients. Paxlovid’s estimated effectiveness in preventing hospitalization or death was 53.6% (95% confidence interval [CI], 6.6% to 77.0%). Effectiveness rose to 79.6% (95% CI, 33.9% to 93.8%) when Paxlovid was received within 5 days of symptom onset.

Among patients who were tested within 5 days of symptom onset and received Paxlovid on the day of the test, estimated effectiveness increased to 89.6% (95% CI, 50.2% to 97.8%). Effectiveness fell to 44% among patients given Paxlovid 6 or more days after symptom onset and those who didn’t have COVID-19 symptoms.

The authors said the findings show the benefit of early Paxlovid treatment among patients with mild to moderate COVID-19, regardless of vaccination status or age. “These findings are even more notable because in this population with high levels of vaccination, we still see additional benefits of this treatment,” senior author Sara Tartof, PhD, of Kaiser Permanente, said in a Kaiser news release.

Among patients who were tested within 5 days of symptom onset and received Paxlovid on the day of the test, estimated effectiveness increased to 89.6%

Tartof noted that Paxlovid is most effective when given soon after symptom onset. “However, there is still some benefit to treatment 6 or more days after symptom onset,” she said. “People should talk with their doctors about the best approach for them.”

Absolute benefits may be low

In a related commentary, Kyle Molina, PharmD, and Adit Ginde, MD, both of Scripps Health, said the low rate of hospitalization and death by 30 days among untreated patients may limit the absolute treatment benefits in a highly vaccinated population infected with Omicron, with the need to treat 100 to 200 patients to prevent one hospitalization or death.

“Studies of whether nirmatrelvir–ritonavir affects additional patient-centred outcomes, such as post-COVID-19 condition (also known as long COVID), are planned and could affect the cost-effectiveness of the intervention and whether continued widespread use is merited as the pandemic evolves,” they wrote. “Characterisation of patients who most benefit from treatment with nirmatrelvir–ritonavir and studies of when treatment is most effective are needed.”

The latest report from the National Academies of Sciences, Engineering, and Medicine highlights the outsized pandemic burdens shouldered by racial-minority and low-income communities, among them the finding that Black, Latino, and Native American children account for 65% of those who have lost a primary caregiver to COVID-19.

The Academies’ Committee on Addressing the Long-Term Impacts of the COVID-19 Pandemic on Children and Families reviewed the literature, commissioned three papers, and held listening sessions with adolescents, educators, juvenile-justice and child-welfare professionals, and Native American tribal leaders.

It is well-known that racial-minority and low-income people are more vulnerable to COVID-19 infection, hospitalization, and death because of work and living conditions and a higher proportion of underlying medical conditions. But they were also more likely to face problems such as unemployment and an inability to fully participate in virtual education because of a lack of technology, a lack of a reliable internet connection, and limited English proficiency, the report, published yesterday, said.  

“In almost every outcome—across measures of social, emotional, behavioral, educational, mental, physical, and economic health and well-being—low-income and racially and ethnically minoritized children and their families have borne, and without intervention will continue to bear, the brunt of the pandemic’s negative effects,” the authors said.

Lower kindergarten enrollment

While the pandemic’s negative effects on all children’s and adolescents’ physical, emotional, and educational well-being are well-documented, the effects on non-White and low-income families and children have been particularly acute, the report said. For example:

Low-income and racially and ethnically minoritized children and their families have borne, and without intervention will continue to bear, the brunt of the pandemic’s negative effects.

• Native American, Black, and Latino children were 4.5, 2.4, and 2.0 times more likely than White children to have lost a parent or other caregiver to the pandemic. Children from these groups, as well as those who don’t speak English at home, were also the most likely to drop out of early-childhood programs.
• Nine percent fewer students enrolled in kindergarten in the 2019-20 school year than in 2019, with larger declines in fully remote school districts, which enrolled more low-income students
• Higher rates of delayed preventive care and vaccinations, with lower uptake among Black and Latino children
• Overdose deaths, most from fentanyl, increased, with the highest rates among Native American youth
• Pregnancy-related death rates rose 33%, with the greatest jumps in Black and Latina women (see related CIDRAP news brief today)

Efforts to lessen pandemic impact

The report also shines a light on school, agency, and community efforts to mitigate the effects of the pandemic and related public health measures, such as school closures and lockdowns. For example:

• Tribal communities promoted physical distancing, vaccination, and masking by basing the recommendations on tribal beliefs about interconnectedness, social responsibility, and the need to protect elders
• Schools pivoted to supporting children and families by, for example, distributing meals, connecting families to social services, and providing technology to ensure access to remote instruction.
• Healthcare organizations implemented telemedicine programs while accommodating large numbers of COVID-19 patients

10 recommendations

To help children and families find a way forward, the committee issued 10 recommendations, asking that:

• Federal agencies, states, Native American tribes, local organizations, and the nonprofit and profit sectors establish a task force on mitigating the effects of the pandemic on children and families, with a focus on Black, Latino, Native American, and low-income families
• State and federal agencies involved in COVID-19 pandemic-relief planning and preparedness for future pandemics address the needs of pregnant women, children, and at-risk communities, including children in the foster-care and juvenile-justice systems
• The US Department of Education renew pandemic funding of high-poverty schools and early-childhood programs, expand the education workforce, prepare for future pandemics, and support children’s academic, emotional, and social recovery
• The US Department of Health and Human Services (HHS) strengthen and expand Medicaid coverage to ensure steady access to physical and mental health services
• HHS further invest in policies and funding to ensure access to quality mental health treatment and behavioral health services in clinical settings, communities, and schools
• The US government incentivize states to expand key safety-net programs, such as Temporary Assistance for Needy Families and child care subsidies
• The federal government support federal paid family leave and sick leave policies or incentivize states to establish their own
• The government reissue and continue the expansion of the Child Tax Credit and distribute it monthly rather than yearly
• Public and private agencies eliminate barriers to collecting child and family data across health, education, social services, juvenile justice, child welfare, and federal and state administrative agencies to optimize services, policies, programs, and research
• Federal agencies prioritize and fund research on the effects of the pandemic on families and children, including adding COVID-related questions to ongoing national studies such as the Youth Risk Behavior Survey and the Head Start Family and Child Experiences Survey

“The effects of the COVID-19 pandemic on children and families may be felt for years to come: for example, research on the 1918 influenza pandemic found long-term physical and mental effects for those who were children or in utero during it,” the authors wrote.

“Understanding and responding to the long-term impact of the pandemic is needed in order to support the health, development, and well-being of children, benefiting not only children and their families, but also society at large.”