Hey Health Deskers,
We hope you’re having a good end to the summer. This week we’ve got a roundup of new research on COVID-19 in kids, plateauing global case counts and what seems to be a breakthrough in mask technology. We’re also unpacking what we know (and don’t know) about asymptomatic infections.
As always, we’re responding to your health questions on-demand and on-deadline, so email us at health@meedan.com or head to health-desk.org and we’ll write up a science break down for your fact-check or report.
First, a look ahead …
Global COVID-19 plateau?
The World Health Organization’s latest situation report shows that after consistent increases in COVID-19 cases for roughly eight weeks, global transmission of the virus appears to be flattening. This good news is highly welcome, as entire continents are still struggling for vaccine access. Not all of the gains are equal, however. Infections in the West Pacific region rose by 20% during this time, largely due to increased spread in countries including the Philippines and Japan. Cases are also up in the Americas—especially in the the United States. However, with over 68,000 new fatalities, deaths across the globe this week are similar to last week's count with noted increases in Europe and the Americas. So far the Alpha, Delta, and Beta variants have been circulating most widely, but international health groups will continue to monitor the development and location of other variants of interest and concern. The global burden of COVID-19 depends on the state of vaccination and virus variants, so we will be paying close attention to their behaviors.
Younger children more likely to spread COVID-19 in households
A recent study from Canada suggests that compared to younger kids, older children may be less likely to spread the virus among their family members. Among 6,280 households, children from zero to eight had higher odds of spreading the virus than children aged fourteen to seventeen. Kids aged three and under had the greatest rates of infectivity.
This is an important finding, despite the specific Western context. Infections among school-aged children and adolescents have been a pivotal concern in the spread of the virus. Children were originally assumed to be lower risk than adults, but it is now clear they are vulnerable. This has strong implications for prevention protocols in schools, daycares, and multi-child settings. It could influence vaccine priorities for high-income countries deciding which kids get their shots first.
New mask breakthroughs
Some types of face masks have been shown to be effective tools in preventing COVID-19 infections. Several research groups have developed innovative new methods to make them even more protective. This week, researchers at the National Autonomous University of Mexico revealed their triple-layered antimicrobial facemask called SakCu that is reusable, washable, and can potentially neutralize SARS-CoV-2. The mask uses silver and copper “nanolayers” which break the virus' membrane and damage its RNA. This led to an 80% disappearance of the virus on the mask within eight hours when viral concentrations were high. There was total destruction of the virus' RNA within two hours when the viral load was low. Innovations like this have shown promise in helping prevent the spread of the virus, especially among those without access to vaccines. With the development of face mask technology around the world, scientists are hoping for more low-cost, easily manufactured options to help those most in need. We expect to see more of these advances in the near future.
You asked, we answered. Here are the latest topics our scientists are unpacking for you:
What do we know about obesity and mortality from COVID-19?
Obesity is a known risk factor for severe COVID-19 outcomes. Data on hospitalized patients in the U.S. showed that individuals with an obese body mass index (BMI) had an increased risk for death from COVID-19. The association for death was even more pronounced among adults less than 65 years old.
“Though it is not a definitive diagnostic tool for health, BMI is used to inexpensively screen an individual’s risk for chronic diseases. Those with an overweight or obese BMI are at a higher risk of a poorer quality of life, all-cause mortality, and other diseases, including Type 2 diabetes, hypertension, coronary heart disease, osteoarthritis, and some cancers.”
Why have daily vaccination rates been changing in the U.S?
From April to July 2021, vaccination rates in the United States were on a decline. They are now increasing again, according to seven-day averages reported by the Centers for Disease Control and Prevention. Chief Medical Advisor Dr. Anthony Fauci predicts that recent full approval of the Pfizer-BioNTech COVID-19 vaccine by the Food and Drug Administration may continue to increase vaccination in the country. This is in line with survey results reported by the Kaiser Family Foundation last June, stating that nearly half of unvaccinated respondents would consider vaccination after full approval. However, local surges of COVID-19 cases in states with a smaller vaccinated population could be a contributor as well.
“Perhaps most notably, the U.S. vaccination effort is seeing upward trends in states where the proportion of vaccinated Americans is the lowest, and COVID-19 cases are the highest. Despite these upticks, vaccination rates are still less than a quarter of what they were in mid-April of 2021.”
What do we know about COVID-19 and smoking tobacco?
In May 2020, the World Health Organization (WHO) published a review of existing studies and meta-analyses (analyses of multiple studies) to assess what is known about the relationship between smoking tobacco and COVID-19. The study specifically looked into how smoking tobacco impacts the risk of COVID-19 infection, hospitalization from COVID-19, and severe infection outcomes, which included intensive care unit (ICU) admission, use of ventilators, and death. With the limited and mixed evidence available, the WHO found that smoking may be associated with a higher risk of more severe disease and a higher risk of death among hospitalized COVID-19 patients.
“Current research on smoking tobacco and COVID-19 infection is limited due to the difficulty of collecting information on smoking history under emergency circumstances. Studies have also not defined “disease severity” consistently, making it difficult to track disease outcomes across studies. Additionally, more research is needed that differentiates between e-cigarette, tobacco use, and the length of tobacco use.”
Why do some people not develop COVID-19 symptoms when they're infected?
Asymptomatic cases are not unique to COVID-19. In fact, asymptomatic cases are common for viral infections. For example, studies have shown that of all human papillomavirus (HPV) infections, more than 90% are asymptomatic cases. The exact reasons for why some people develop COVID-19 symptoms and others do not is unknown, but we do know that the healthier you are, the more likely you are to have an asymptomatic case. There are several pathways being explored as possible explanations for asymptomatic cases. They include age, genetics, environment, vaccination and “cross-immunity.”
“Cross immunity is the idea that past exposure to one virus—either through infection or vaccination—could provide partial protection against another virus. Studies suggest that cross-immunity can lead to asymptomatic COVID-19 cases. One example is the Bacillus Calmette–Guérin (BCG) vaccine used to prevent tuberculosis. Recent data suggest that regions with required BCG vaccines have had lower rates of COVID-19 cases and deaths. In addition, the BCG vaccine has been shown to reduce the viral load of other viruses like the flu. This suggests that BCG vaccines could boost immunity against COVID-19 and decrease inflammation, leading to less symptoms. However, further studies are needed. ”
That’s all for this time folks, have a good week and we’ll be back soon with more science to share!