Silver Bullet June 25 - Birthday parties and COVID, long COVID updates, vaccine concerns
A weekly update on all things COVID-19. News, public health guidance, trends, breakthroughs, and thousands of scientific papers distilled down to what you need to know right now.
Happy COVID to you
A report in JAMA Internal Medicine linked higher rates of COVID-19 to households with recent birthdays. Those households were 30 percent more likely to have a COVID-19 diagnosis. The researchers used data from a sample of nearly 3 million US households drawn from health insurance claims. The relationship was based on birth dates as a proxy for in person social gatherings. In the first 45 weeks of 2020, in counties with high COVID-19 transmission, households with recent birthdays averaged 8.6 more cases per 10,000 than households in the same counties without a recent birthday. If it was a child’s birthday, the risk was even greater, with 15.8 cases per 10,00 in the two weeks following the birthday. The study illustrates the role that social gatherings play in spreading COVID-19.
Is SARS-CoV-2 hitching a ride on tree pollen?
If you have allergies, this is the stuff of nightmares. A new study in Physics of Fluids illustrates how airborne pollen grains can contribute to the spread of airborne viruses, especially among crowds. The researchers were inspired by the correlation between COVID-19 infection rates and pollen concentrations on the National Allergy Map. Using computational modeling of fluid dynamics to mimic the movement of willow tree pollen, they found that 10,000 pollen grains could distribute through a crowd of 100 people in less than one minute. If a few people in the crowd are infected with COVID-19, this distribution of pollen grains could increase the airborne transmission distance well beyond the generally accepted range of 6 feet of social distance. However, this study is just theoretical. Other studies have shown that very little COVID-19 transmission occurs outdoors—or almost none.
Super-long COVID successfully treated with two new antibodies
Researchers from the University of Bristol and North Bristol NHS Trust treated an immunocompromised person with the longest known PCR-confirmed infection with SARS-CoV-2 with two experimental monoclonal antibodies (casirivimab and imdevimab), resulting in a dramatic improvement in the patient’s health, and undetectable virus levels 45 days later. The patient had previously been treated with a 15-day course of Remdesivir, which failed to clear the infection. Notably, the virus evolved within the patient over the course of the infection, eventually acquiring mutations known to be present in variants of concern. Immunocompromised people are thought to be potential incubators of new viral variants, because of their weakened immune systems. The case is published on the MedRxiv preprint server, and has not yet been peer reviewed.
Long COVID is common after mild illness
More than half of young adults age 16 to 30 had persistent symptoms of COVID-19 six months after mild-to-moderate infection in a new study from Norway’s first wave. Lingering symptoms included loss of taste or smell, fatigue, shortness of breath, poor concentration, and memory problems. From the paper: “It is worrying that non-hospitalized, young people (16–30 years old) suffer potentially severe symptoms, such as concentration and memory problems, dyspnea and fatigue, half a year after infection. Particularly for students, such symptoms might interfere with their learning and study progress.”
Delta variant raises hospitalization risk, vaccines remain effective
According to a letter published in The Lancet, the COVID-19 Delta variant approximately doubles the risk of hospitalization compared to the wild type virus (Alpha). However, two doses of vaccine still provide strong protection, albeit somewhat reduced from the original strain. The Delta variant was first detected in India, and has been blamed for India’s devastating surge earlier this year. It has now been found in more than 80 countries and is rapidly overtaking previous variants. It is responsible for 90% of all new infections in the United Kingdom, and in the US it currently accounts for 20% of new infections. (Via AP)
Plant-based and pescatarian diets may protect from severe COVID-19
A study in BMJ Nutrition, Prevention, and Health details the first study connecting dietary patterns to severity of COVID-19 infection. Looking at health care workers from five European countries and the US, the researchers found that participants who reported following either a plant-based diet or a pescatarian diet had significantly lower odds of moderate-to-severe COVID-19 compared with participants who did not follow those diets. When comparing people following a plant based diet with those following a low carb, high protein diet, the low carb, high protein group had greater odds of moderate-to-severe COVID-19. The study concludes that plant-based and pescatarian diets may offer protection against severe COVID-19.
Physicians urge FDA not to prematurely approve COVID vaccines
A group of 27 clinicians, researchers, and consumer advocates signed a letter published in thebmj detailing a citizen petition filed with the US FDA, requesting that the agency not rush to approve COVID-19 vaccines currently in use under emergency use authorizations. They request that the vaccines be considered for full approval based on complete Phase III clinical data, with a full two years of data, and with additional studies including assessment of distribution, pharmacokinetics, and toxicities of spike proteins produced in situ following vaccination. They also request studies in specific populations, and for a careful consideration of all serious adverse events reported. Surveys have suggested that some vaccine hesitancy in the US is due to a lack of full FDA approval. “While approval might lead to increased public confidence in COVID-19 vaccines, as well as provide legal support for employer-instituted vaccine mandates, to approve a medical product for these reasons is outside FDA’s regulatory purview,” they wrote.
Single dose vaccination reduces transmission
In a UK analysis of data on household transmission of COVID-19, researchers found that infected people who had been vaccinated with the AstraZeneca or Pfizer-BioNTech vaccines at least 21 days before testing positive were 40-50% less likely to transmit the virus to other members of their households than unvaccinated people. During the study period (Jan-Feb 2021), the UK had a policy of delaying second vaccine doses in order to stretch the supply. Thus, 93% of the vaccinated index patients had only had one dose of vaccine, which means this study is largely not reflective of transmission by fully vaccinated individuals.
Possible link between Guillain-Barré syndrome and AstraZeneca vaccine
Two recent papers detail rare instances of an unusual variant of Guillain-Barré syndrome associated with the AstraZeneca COVID-19 vaccine. The papers, published in Annals of Neurology, document four cases from Nottingham, England and seven cases from Kerala, India. The cases were distinguished by a “disproportionately frequent and severe bilateral facial paresis,” according to an accompanying commentary, “No, it’s not 1976 all over again.” Similar cases have been reported in the vaccine adverse event reporting system after vaccination with the Johnson and Johnson vaccine (although these cases have not been definitively linked to the vaccine). What the JnJ and AstraZeneca vaccines have in common is the use of an adenovirus vector that carries the vaccine machinery, and that raises questions about whether the vector itself should be studied as a source of those events.
Other science news
Growing evidence for link between red meat and colon cancer
Consumption of red meat has had a known association with colon cancer for some time. Now a potential mechanism for that association has been identified. In a study of tumor tissue from 900 patients with colorectal cancer, DNA sequencing revealed mutational signatures of a specific form of DNA damage called alkylation that were associated with pre-diagnosis consumption of processed or unprocessed red meat, but not poultry, fish, or any other lifestyle factors. They were able to identify two genes, KRAS and PIK3CA as possible hot spots for this type of alkylation damage. These are known cancer-driver mutations. The authors conclude that red meat consumption may cause alkylating damage to DNA, leading to cancer, supporting red meat intake as a risk factor for colon cancer.
For some, exercise can increase risk of ALS
Strenuous exercise can increase the risk of ALS (or motor neuron disease) in people with a genetic predisposition. Research published in EBioMedicine confirms previous studies showing a six-fold increased risk of motor neuron disease in professional soccer players compared to the general population. It is hoped that eventually, testing for this genetic risk factor will be available so that people affected can modify their exercise habits accordingly.
In depth
The delta variant is a rising threat in the US. We have to redouble vaccination efforts. by Ashish Jha, The Washington Post
They relied on Chinese vaccines. Now they’re battling outbreaks. by Sui-Lee Wee, The New York Times
Let’s recognize childhood COVID as the crisis it is by Edward Nirenberg and Risa Hoshino, MD, MedPage Today
White house says it reached its vaccine goal—kinda by Joyce Frieden, MedPage Today