COVID Booster

An accurate saliva COVID test

A group of US researchers has developed a saliva-based test for SARS-CoV-2 that can give accurate results in 30 minutes.

The hand-held device that can accurately test salive for sars-cov-2.
The hand-held device that can accurately test saliva for SARS-CoV-2. Credit: L. Brian Stauffer

“We developed a rapid, highly sensitive and accurate assay, and a portable, battery-powered device for COVID-19 testing that can be used anywhere at any time,” says Huimin Zhao, a professor at the University of Illinois Urbana-Champaign, and senior author on a Nature Communications paper describing the device.

The prototype device costs around US$78 in total (approximately AUD$100), and would be around US$6-7 per test (AUD$8-9). Most of the parts can be 3D printed, and it needs saliva rather than the uncomfortable nose swab.

“Based on the data reported in the literature, the accuracy of our test is comparable to or better than other SARS-CoV-2 tests,” says Zhao.

“We are interested in exploring this technology for detection of other diseases as well.”

Nearly a million excess deaths in 29 countries alone

The official death toll from COVID-19 is undeniably lower than the actual death toll. Low testing rates mean not every COVID death was recorded, and pandemic disruption and overwhelmed health systems around the world led to more deadly non-COVID conditions.

A study published in the BMJ has examined “excess deaths” in 29 high-income countries – meaning numbers of deaths that were above the expected death toll in 2020.

The US, for instance, can expect around 2.8 million deaths per year. The study found that on top of this, the US experienced an additional 458,000 deaths that were not expected based on statistics.

In total, the 29 countries recorded 979,000 excess deaths.

New Zealand, Norway and Denmark were the only three countries in the study with fewer deaths than expected. New Zealand had 2500 fewer deaths than expected (it normally records around 33,000 deaths per year).

Australia was not included in the study.

More interest in home births during the pandemic

Online searches for home birthing have increased during the pandemic – at least in the US and the UK. A paper published in JAMA Network Open has suggested this means an increased interest in home birthing as hospitals underwent pandemic restrictions.

The US saw a relatively higher number of home-birth related searches than the UK, which the researchers say may reflect the UK’s “higher baseline rate of home births and more integrated home birth system prior to the pandemic”.

“These results have important implications for birth workers as they consider shifts in patient birthing preferences,” write the authors.

“Close collaboration between patients, home birth practitioners, and hospital-based practitioners is vital to promote resource sharing and optimize patient care.”

“Stealth nanoparticles” could treat COVID-19

A team of researchers, including Australians, has developed a direct antiviral treatment for coronaviruses that is showing some success in animal trials.

The treatment uses a new technology called siRNA (small-interfering RNA) to attack the genome of the virus, preventing it from replicating.

“Treatment with virus-specific siRNA reduces viral load by 99.9%,” says Nigel McMillan, a professor at Griffith University. “These stealth nanoparticles can be delivered to a wide range of lung cells and silence viral genes.

“Treatment with the therapy in SARS-Cov-2 infected mice improved survival and loss of disease. Remarkably, in treated survivors, no virus could be detected in the lungs.”

“This treatment is designed to work on all betacoronaviruses such as the original SARS virus (SARS-CoV-1) as well as SARS-CoV-2 and any new variants that may arise in the future because it targets ultra-conserved regions in the virus’ genome,” says Kevin Morris, a professor at Griffith University and City of Hope in the US.

“These nanoparticles are scalable and relatively cost-effective to produce in bulk.”

The nanoparticles are discussed in a paper in Molecular Therapy.

Review on immune system responses could inform vaccine development

An analysis published in Nature Medicine has suggested that the early immune response in someone vaccinated for COVID-19 can predict their vulnerability to the virus over time.

“While we have known for some time that neutralising antibodies are likely to be a critical part of our immune response to COVID-19, we haven’t known how much antibody you need for immunity. Our work is the strongest evidence to date to show that specific antibody levels translate to high levels of protection from disease,” says Deborah Cromer, a researcher at the Kirby Institute.

The paper identified an “immune correlate” of vaccine protection, which could be used to predict vaccine efficacy when trials are in their early stages.

“Antibody immune levels are much easier to measure than directly measuring vaccine efficacy over time,” explains Cromer. “So, by measuring antibody levels across the range of new vaccine candidates during early phases of clinical trials, we can better determine whether a vaccine should be used to prevent COVID-19.”

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