COVID Booster: Heart failure theories, optimising lockdowns, and breathing into a cone for 30 minutes

Lockdown dissolves a heart failure theory

Around the world, there’s an uptick in heart failures each winter, and it’s not entirely clear why. One theory was that respiratory diseases, like colds and influenza, contributed to the peak because they surge at the same time.

A paper in Respirology has challenged this theory, showing that while respiratory diseases plummeted in New Zealand over 2020, thanks to their restrictions, there wasn’t a matching drop in heart failures.

“Despite unprecedented low/absent levels of circulating respiratory viruses in the winter of 2020, we did not observe a significant change in the number of admissions for heart attacks and heart failure,” writes Dr Cat Chang, a researcher at Waikato Hospital, NZ, and an author on the paper.

“This suggests that the proposed viruses causing more winter cardiovascular disease is not the main contributing factor in our population.

“Our study analysed national admission trends for the first 33 weeks of the year (up to when Auckland went into a second lockdown) as the whole country can be viewed as one bubble. We have plans to analyse the remaining weeks of 2020 through to winter 2021 and study further trends in respiratory viruses in New Zealand.”

Australian vaccine advances another step

A Flinders University-developed vaccine has been shown to be effective at stopping COVID-19 transmission in animals.

COVAX-19 uses a synthetic protein that has been designed to be similar to the SARS-CoV-2 spike protein. The protein is combined with an adjuvant (a substance that activates the immune system), and it’s currently wrapping up Phase II clinical trials in people in the Middle East.

A paper published in Vaccine has demonstrated that the vaccine blocks symptomatic infection in ferrets and mice, and it also may prevent transmission of COVID-19.

“The key to overcoming the pandemic lies in developing an effective vaccine against SARS-CoV-2 that not only prevents infection and clinical disease but also blocks virus transmission,” says Nikolai Petrovsky, professor of medicine at Flinders University and lead researcher on the vaccine.

The researchers had noticed that the vaccine, when tested on mice which were then infected with COVID, spurred low nasal shedding of the virus.

“We’ve now taken this data on lack of nasal shedding and set up a US-based study in the hamster model to specifically test for the ability of our vaccine to reduce transmission to naïve animals,” says Petrovsky.

“A transmission-blocking effect would be a game changer as this is what is currently needed to stop further virus outbreaks.”

Fine aerosols from talking and singing might be a big part of transmission

Singaporean and US researchers have examined the risk of SARS-CoV-2 transmission from very small aerosols, finding they may be a key part.

Published in Clinical Infectious Diseases, the study got 22 COVID-positive patients to place their head in a device called the “Gesundheit-II” (pictured) and do three different activities over one day: breathe for 30 minutes, sing for 15 minutes, and read aloud for 15 minutes.

The device collected all exhalations from the extremely cooperative participants, and the researchers examined SARS-CoV-2 particles in the aerosols they breathed.

“We observed that COVID-19 patients who are early in the course of illness are likely to shed detectable levels of SARS-CoV-2 RNA in respiratory aerosols,” says Dr Kristen Coleman, lead author on the paper.

“However, person-to-person variation in virus emission was high. Some patients surprisingly released more virus from talking than singing.”

Fine aerosols – less than 5 micrometres, roughly the same width as spider silk and slightly smaller than human hairs – were found to contain more viral particles than larger aerosols.

The data was collected in early 2021, and the researchers now hope to examine patients with the Delta variant.

Supercomputers could tune lockdown strategies

A group of UK researchers have developed a computer model that uses real-time mobility data from smartphones to model lockdown policies.

The researchers used mobility data from Google to inform their mathematical models, showing how some areas could be opened up in a lockdown with still minimal transmission.

“Our work opens the door to a larger integration between epidemiological models and real-world data to, through the use of supercomputers, determine best public policies to mitigate the effects of a pandemic,” says Ritabrata Dutta, lead author on a paper describing the research, published in PLOS One.

“In a not-so-distant future, policy makers may be able to express certain prioritization criteria, and a computational engine, with an extensive use of different datasets, could determine the best course of action.”

Sugar trap might catch virus

A group of Austrian researchers have spotted two compounds that could prevent SARS-CoV-2 infection by mimicking human proteins.

The researchers, who have published their findings in The EMBO Journal, examined the effectiveness of a variety of lectins – proteins that bind to sugar molecules – against coronavirus spike proteins. Many of the lectins were similar to human ACE2 receptors, which is what SARS-CoV-2 uses to get into our cells.

“We intuitively thought that the lectins could help us find new interaction partners of the sugar-coated spike protein,” says co-first author David Hoffmann.

The researchers found two lectins that could bind to the virus proteins, thus preventing it from binding to our ACE2 receptors. The researchers say that this could be a therapeutic treatment in future.