Tip on sars-cov-2 spike protein

COVID Booster

Cities encouraging cyclists, with good results

Aside from being cheap and environmentally friendly, a bicycle is one of the least risky ways to commute in terms of COVID-19 transmission. At the start of the COVID crisis, many European cities encouraged cycling by establishing pop-up bike lanes.

Now, a paper published in PNAS shows that the pop-up lanes have been effective, leading to an increase in cycling traffic of between 11% and 48%.

The researchers, based at Clark University in the US, examined 106 European cities that had announced intentions to build pop-up lanes. They found that within four months of the announcement, an average of 11.5km of pop-up bike lanes had been built per city. Bicycle counters in the cities showed that people were cycling more with the establishment of these lanes.

If the cycling habits persist, the researchers point out it could lead to between $1 billion and $7 billion in health benefits per year. The cost of the lanes was fairly low for infrastructure, with Berlin paying €9,500 (approx. AUD $14,600) per kilometre of lane.

New targets for COVID vaccines

A visualisation of the SARS-CoV-2 spike protein, with vulnerable sites in purple and shielding glycan molecules shown in green. Credit: Mateusz Sikora, Sören von Bülow, Florian E. C. Blanc, Michael Gecht, Roberto Covino and Gerhard Hummer

A new model of the SARS-CoV-2 spike protein has located molecules on its surface that could inform further vaccine development.

Researchers from the Max Planck Institute of Biophysics used molecular dynamics simulations to examine how the spike protein moved in a realistic environment. They found that small, sugar-like molecules called glycans flopped back and forth on the spike protein, meaning they covered a wider surface than initially thought. This ‘windshield wiper’ motion allowed the glycans to shield the spike protein from the body’s immune system.

The researchers were able to find spots on the spike protein that weren’t as well protected by the glycans. They suggest that these sites could be more vulnerable, making them suitable targets for vaccines.

“We are in a phase of the pandemic driven by the emergence of new variants of SARS-CoV-2, with mutations concentrated in particular in the spike protein,” says Mateusz Sikora, a researcher at the Max Planck Institute and lead author on a paper describing the research in PLOS.

“Our approach can support the design of vaccines and therapeutic antibodies, especially when established methods struggle.”

Antibodies against variants of concern

A paper published in Nature has shown that immunity to some COVID-19 variants is more effective than others, meaning vaccines should target certain variants.

The study examined antibodies in plasma from 20 people infected in the first and second waves of coronavirus in South Africa, where the second wave was driven by the more infectious 501Y.V2 variant. All 6 patients from the second wave had the 501Y.V2 variant.

Antibodies from the first wave patients were ineffective at neutralizing the 501Y.V2 virus, but antibodies from second-wave patients could neutralize the virus from the first wave.

The researchers conclude that vaccines targeting 501Y.V2 may be more effective against other variants. This comes as vaccine trials from Novavax, Johnson and Johnson and Astrazeneca suggest that their vaccines are not as effective against the new variant.

A fast test for catching variants

A team of scientists led by NTU Singapore has developed a diagnostic test that can detect SARS-CoV-2 even after it has gone through mutations. Credit: NTU Singapore

Researchers at the Nanyang Technological University in Singapore have developed a fast test to spot COVID-19 and its mutations.

The test, called the VaNGuard test, uses CRISPR to detect segments of the SARS-CoV-2 genome. It can deliver a result in 30 minutes, and is sensitive to mutant strains of the virus.

The test operates on a paper strip, showing coloured lines in the case of a positive result.

“Viruses are very smart. They can mutate, edit, or shuffle their genetic material, meaning diagnostic tests may fail to catch them,” says Tan Meng How, an associate professor at NTU Singapore.

“Hence, we spent considerable effort developing a robust and sensitive test that can catch the viruses even when they change their genetic sequences. In addition, frequent testing is essential for helping to break the transmission of viruses within populations, so we have developed our tests to be rapid and affordable, making them deployable in resource-poor settings.”

The test is described in a paper published in Nature Communications.

Smokers want to quit to help others

A survey of 1500 smokers in Australia, New Zealand and the UK has found that many want to quit to avoid stressing the health system further during the COVID-19 pandemic.

The study, run by the George Institute for Global Health and published in Nicotine & Tobacco Research, found that the largest increase in intentions to quit came in response to information about how quitting would reduce pressure on the health system during COVID. This information was more compelling than information about smokers’ personal health or financial wellbeing.

The study also found that smokers deemed messages about quitting during COVID to be acceptable, believable and personally relevant, and 44% of respondents chose to look at more information about their COVID-related risks as smokers.

“There is strong awareness in the community that smoking increases people’s risk of diseases such as stroke and cancer, but COVID is shining a light on how it also affects people’s immunity and their ability to recover from infectious diseases,” says Simone Pettigrew, lead author on the paper and a professor at the George Institute for Global Health.

“We already know that most smokers want to quit, and COVID seems to be providing an additional impetus through smokers’ concerns about the ability of the health system to cope with current demands.”