Mutations of COVID-19 virus unlikely to affect existing vaccines

New research by CSIRO, Australia’s national science agency, has shown potential vaccines should not be affected by how SARS-CoV-2, the virus that causes COVID-19, has changed to date.

Most vaccines under development worldwide have been modelled on the original ‘D-strain’ of the virus, which were more common amongst sequences published early in the pandemic. Since then, the virus has evolved such that the ‘G-strain’ is globally dominant. The G variant now accounts for about 85% of published SARS-CoV-2 genomes, CSIRO said.

There had been fears that the G-strain, or ‘D614G’ mutation within the main protein on the surface of the virus, would negatively impact on vaccines under development. Researchers have found no evidence to date that the change would adversely impact the efficacy of vaccine candidates.

Source: CSIRO. Biomolecular
modelling of the
COVID-19 spike protein.

Published today in npj Vaccines, the study tested blood samples from ferrets vaccinated with Inovio Pharmaceuticals’ INO-4800 candidate against virus strains that either possessed or lacked this ‘D614G’ mutation. 

The study was undertaken in parallel to the pre-clinical trial of INO-4800 at the Australian Centre for Disease Preparedness (ACDP), CSIRO’s high-containment biosecurity facility in Geelong, Victoria.

CSIRO Chief Executive Dr Larry Marshall said the research was critically important in the race to develop a vaccine. “This brings the world one step closer to a safe and effective vaccine to protect people and save lives,” Dr Marshall said.

"Research like this, at speed, is only possible through deep collaboration with partners both in Australia and around the world.

“We are tackling these challenges head-on, together, and delivering real world solutions from world-leading Australian science.”

Dr SS. Vasan, CSIRO’s Dangerous Pathogens Team Leader and the senior author of the paper, said this was good news for the hundreds of vaccines in development around the world, with the majority targeting the spike protein.

“Most COVID-19 vaccine candidates target the virus’ spike protein as this binds to the ACE2 receptors in our lungs and airways, which are the entry point to infect cells,” Dr Vasan said.

“Despite this ‘D614G’ mutation to the spike protein, we confirmed through experiments and modelling that vaccine candidates are still effective.

“We’ve also found the G-strain is unlikely to require frequent ‘vaccine matching’ where new vaccines need to be developed seasonally to combat the virus strains in circulation, as is the case with influenza.”

Dr Alex McAuley, CSIRO research scientist and first author of the paper, said ferrets vaccinated with INO-4800 demonstrated a strong immune response.

“We found that ferrets vaccinated with Inovio Pharmaceuticals’ candidate developed a good B-cell response in terms of neutralising antibodies against SARS-CoV-2 strains, which is important for the short-term efficacy of a vaccine,” Dr McAuley said.

“We are also studying the T-cell response which is important for long-term efficacy.”

The Victorian Infectious Diseases Reference Laboratory provided a G-strain isolate from a patient sample to enable this study. The results of the study were further interpreted with biomolecular modelling conducted by CSIRO's digital specialist arm, Data61.

The modelling enabled the interactions between the vaccine and virus to be simulated and visualised, according to Dr Michael Kuiper, co-author and Team Leader of the Molecular & Materials Modelling Group at CSIRO’s Data61.

“If we understand the process of a viral infection, we paint a picture of its vulnerabilities. Biomolecular modelling helps us to do this,” Dr Kuiper said.

“By visualising molecular structure, we were able to support the study’s inference that the immune response generated by the vaccine candidate is equally effective against both D- and G- strains of SARS-CoV-2.”

CSIRO recently concluded preclinical studies for two vaccine candidates (from Inovio Pharmaceuticals and the University of Oxford) at the ACDP, with peer-reviewed reports to be published in the coming months.

Explore:

Read the paper.

Breakfast protein could help with weight loss

Source: CSIRO.
Protein in the morning
could help with weight
management.

Eating more protein, especially at breakfast, could be the key to achieving healthy weight loss, according to a new report from CSIRO. Protein Balance: New concepts for protein in Weight Management, affirms the benefits of the CSIRO Total Wellbeing Diet for weight control and reveals that the latest scientific evidence supports eating at least 25g of protein at each main meal to control hunger and enhance muscle metabolism.

The new Total Wellbeing Diet Protein Balance programme focuses on shifting more protein consumption to breakfast. "The average Australian eats much lower amounts of protein at breakfast, so increasing breakfast protein may help to control eating later in the day," Senior Principal Research Scientist for CSIRO and co-author of the CSIRO Total Wellbeing Diet, Professor Manny Noakes, said.

"If you find it difficult to control what you eat, a redistribution of protein toward breakfast may be the answer to reducing your waistline without leaving you ravenously hungry and craving unhealthy foods."

According to the report, Australians get over one third of their dietary protein from low-quality sources such as processed foods, instead of whole protein sources including lean meats, fish, eggs, legumes and dairy. The CSIRO report showed that for most Australians, protein intake was skewed towards the evening meal, with only small amounts eaten at breakfast. On average women consumed 11g of protein at breakfast, compared to the male average of 15g.

The report also found that older Australians consumed the least amount of protein at breakfast but needed more protein to prevent muscle loss. "The scientific evidence supports a higher protein diet, combined with regular exercise, for greater fat loss. Eating at least 25g of protein at main meals can assist with hunger control," Professor Noakes said.

Adopting a higher protein, moderate carbohydrate, low Glycemic Index (GI) diet is a nutritious way to lose weight and has been scientifically validated for some time, underpinning successful programmes such as the CSIRO Total Wellbeing Diet. Since launching in 2005, the CSIRO Total Wellbeing Diet has helped more than half a million Australians lose weight.

"Two in three Australian adults are either overweight or obese, which increases their risk factors for many chronic health conditions," Professor Noakes said. "With a variety of genetic, lifestyle and personality factors at play, there is no such thing as a one-size-fits-all approach to weight loss, but there is a range of healthy ways to lose weight.

"If we're serious about addressing this issue we need to continue developing a wider range of scientifically validated ways for people to lose weight, which is something CSIRO has done successfully over the years. Introducing the new Protein Balance programme for the Total Wellbeing Diet is another example of that."

Details:

The Total Wellbeing Diet 12 Week Program costs A$149 which is fully refundable if the subscriber successfully completes the programme.

New designer crystals could create more powerful devices

Source: CSIRO. Dr Styles.

A new process that uses vapour– rather than liquid – to grow designer crystals could lead to faster, more powerful electronic devices. The crystals are the world's most porous materials, and if applied to microelectronic devices, could significantly boost their processing power.

For the first time, researchers have shown how the designer crystals known as metal organic frameworks (MOFs), can be grown using a vapour method that is similar to steam hovering over a pot of hot water. The method, invented by scientists from the University of Leuven in Belgium, the National University of Singapore and CSIRO has been published in the journal Nature Materials.

According to CSIRO researcher Dr Mark Styles, the crystals could previously only be grown and applied using a liquid solvent, making them unsuitable for electronics applications. "Just like your smart phone doesn't like being dropped in water, electronic devices don't like the liquid solvent that's used to grow MOF crystals," Dr Styles said. "It can corrode and damage the delicate circuitry. Our new vapour method for growing and applying MOF crystals overcomes this barrier and has the potential to disrupt the microelectronics industry.

"On the atomic scale, MOF crystals look like bird cages that can be tailor-made to be different shapes and sizes. They have an extremely large surface area, meaning they can be up to 80% empty inside. The net result is a structure where almost every atom is exposed to empty space: one gram of MOF crystals has a surface area of over 5,000 sq m – that's the size of a football field. Crucially, we can use this vast space to trap other molecules, which can change the properties of a material. In the case of electronics, this means we can fit a lot more transistors on a microchip, making it faster and far more powerful."

The international team, which was led by Ivo Stassen and Professor Rob Ameloot from the University of Leuven in Belgium, drew on specialist X-ray analysis techniques from CSIRO and the Australian Synchrotron to understand how the vapour process works, and how it can be used to grow the MOF crystals.

According to Dr Styles, the applications for MOFs can only be limited by your imagination. "Another potential use for this technology would be in portable chemical sensing devices that could be used in hazardous environments such as chemical processing plants and underground mines," he said.

Interested?

Read the Nature paper

posted from Bloggeroid

Malaria may soon be detected with a simple breath test

Source: CSIRO. Tests such
as this one, which captures
exhaled breath for chemical
analysis, may soon be used to
detect malaria.

Australian scientists at CSIRO, QIMR Berghofer Medical Research Institute and the Australian National University have made a significant discovery that could lead to a simple and quick "breath test" for malaria. Current malaria diagnosis techniques focus on using microscopes to look for parasites in blood, using a method discovered in 1880. 

The researchers looked at the breath of volunteers who had been given a controlled malaria infection as part of existing studies to develop new treatments, and found that the levels of some normally almost undetectable chemicals increased markedly in the breath of the volunteers during the malaria infection.

"What is exciting is that the increase in these chemicals were present at very early stages of infection, when many other methods would have been unable to detect the parasite in the body of people infected with malaria," Dr Stephen Trowell, Research Group Leader at CSIRO said.

"In addition to its potentially better sensitivity, human breath offers an attractive alternative to blood tests for diagnosing malaria."

The study, published in the Journal of Infectious Diseases, was conducted in two independent studies where experimental drug treatments were being tested in volunteers who had been given a very small dose of infection.

Using a sophisticated analytical instrument, the researchers identified four sulphur-containing compounds whose levels varied across the time course of the malaria infection.

"The sulphur-containing chemicals had not previously been associated with any disease and their concentrations changed in a consistent pattern over the course of the malaria infection," Professor James McCarthy, Senior Scientist in Clinical Tropical Medicine at QIMR Berghofer said. "Their levels were correlated with the severity of the infection and effectively disappeared after they were cured."

"Now we are collaborating with researchers in regions where malaria is endemic, to test whether the same chemicals can be found in the breath of patients," Dr Trowell said.

"We are also working with colleagues to develop very specific, sensitive and cheap 'biosensors' that could be used in the clinic and the field to test breath for malaria."
In 2013, according to the WHO, there were almost 200 million cases and over half a million deaths due to this disease.