Coronavirus science | Week in review: Latest on vaccines, and researchers develop new face mask



READ | Covid-19: Should people be paid to get vaccinated?

Global surveys have been showing worrying signs of Covid-19 vaccine hesitancy – the reluctance or refusal to be vaccinated due to safety concerns.

For scientists, this only adds to the existing stress of trying to control the pandemic, given that the safest way to reach herd immunity, or “herd protection”, is through an effective vaccine.

However, according to leading ethicist, Professor Julian Savulescu from the Oxford Uehiro Centre for Practical Ethics, University of Oxford, incentivising people to be vaccinated, if one becomes available, may be the solution.

Savulescu, whose opinion piece was peer-reviewed and published in the Journal of Medical Ethics, says that to obtain the necessary level of herd immunity – which could be just over 80% of the population – an incentive (either financial or "payment in kind"), must therefore be considered by governments worldwide.

An incentive in kind, for instance, is allowing people the “freedom to travel, to not wear a mask in public places if you carried a vaccination certificate, and not to physically distance", he writes.

Herd immunity, as explained by Nature, occurs when a virus can’t spread as it keeps encountering people who are protected against infection. The form of protection is typically discussed as a result of widescale vaccination programmes.

READ | Coronavirus: Different antibodies produced in response to coronavirus in children, study finds

The new coronavirus spares most children, and researchers of a study may know why. According to their findings, children and adults produce different types and amounts of antibodies in response to infection.

The researchers from Columbia University Vagelos College of Physicians and Surgeons wrote that the differences in antibodies suggest the period of infection, as well as the immune response, is distinct in children. They also found that most children easily clear the virus from their bodies.

"Our study provides an in-depth examination of SARS-CoV-2 antibodies in kids, revealing a stark contrast with adults," Dr Donna Farber, Columbia University immunologist and co-author of the study, said in a news release.

Dr Matteo Porotto, associate professor of viral molecular pathogenesis in Columbia's Department of Pediatrics, led the study with Farber and commented that because children may clear the virus more efficiently than adults, they may not need a strong antibody immune response to get rid of it.

They also wrote that, since children's cells express fewer proteins the virus needs to infect human cells, it could explain why the virus is less able to infect children's cells compared to adults.

Their findings were published in the journal Nature Immunology.

READ | The latest news on a leading Covid vaccine candidate is promising, but how optimistic should we be?

Drug maker Pfizer said on Monday data from their Phase 3 experimental Covid-19 vaccine, BNT162b2, showed it was 90% effective in preventing infections in volunteers.

The company and its collaborator, BioNTech, stated no serious safety concerns were found during their large-scale global clinical trials, and they expected to seek US authorisation this month for emergency use of the vaccine.

The data released was based on global data that included the trial site in South Africa, a Pfizer spokesperson told Health24.

"We are pleased to share that the trial in South Africa is going as planned, having already completed recruitment of participants across four sites in Gauteng, Limpopo and the Western Cape," the company said.

While there are still some unanswered questions, such as how long the vaccine will provide protection, international scientists have welcomed the news saying it "is an excellent result for a first generation vaccine".

Health24 asked two local experts, Professor Wolfgang Preiser, head of the division of medical virology at the University of Stellenbosch, and Professor Thomas Scriba, deputy director of immunology and laboratory director at the South African Tuberculosis Vaccine Initiative, University of Cape Town, whether this was finally a light at the end of the tunnel of the Covid-19 pandemic.

READ | 'Hidden' gene discovered in Covid-19 virus could give more insight into its ability to spread

Researchers from the American Museum of Natural History have identified a new "hidden" gene in SARS-CoV-2, the virus that causes Covid-19, and say this may explain why it is so highly infectious.

The discovery of the “overlapping gene”, named ORF3d, could have a significant impact on how we combat the virus, the research team wrote. Overlapping genes (OLGs) are a type of 'gene within a gene', effectively concealed in a string of nucleotides, ScienceAlert explains.

"Overlapping genes may be one of an arsenal of ways in which coronaviruses have evolved to replicate efficiently, thwart host immunity, or get themselves transmitted," said lead author Chase Nelson, a postdoctoral researcher at Academia Sinica in Taiwan and a visiting scientist at the American Museum of Natural History.

"Knowing that overlapping genes exist and how they function may reveal new avenues for coronavirus control, for example through antiviral drugs."

Their findings were published in the journal eLife.

According to the team’s findings, the newly discovered gene is present in a previously discovered pangolin coronavirus. This, they say, possibly reveals repeated loss or gain of this gene during the evolution of the new coronavirus, as well as related viruses.

READ | Researchers develop special cotton face mask that can be disinfected by the sun

It's been proven in several studies that face masks help to limit the spread of the new coronavirus as the virus is mainly transmitted through respiratory droplets (when people cough, sneeze, or talk) and personal contact.

Although masks protect the people wearing them by reducing the number of droplets from others reaching their respiratory tract, evidence suggests that different types of masks yield different results.

More than this, live bacteria and viruses can easily stick to the surfaces of masks, and be transferred elsewhere as soon as the wearer touches or removes it.

Taking this into consideration, researchers from the American Chemical Society developed a special kind of cotton face mask that kills up to 99.9999% of bacteria and viruses within 60 minutes of daylight exposure.

Their findings were recently published in the journal ACS Applied Materials & Interfaces.

Peixin Tang, Gang Sun, Nitin Nitin, and colleagues aimed to develop a new cotton fabric that would release reactive oxygen species (ROS) when exposed to daylight, killing microbes attached to the fabric's surface.

They also wanted the fabric to be washable, reusable, and safe to wear.

This invention would also be convenient as wearers could disinfect the mask during their lunch hour outside in the sun. The same effect could also be achieved by spending longer periods of time under office or building lights, which are much less intense than sunlight.


SA cases update: 

The latest number of confirmed cases is 751 024.

According to the latest update, 20 241 deaths have been recorded in the country.

There have been 693 467 recoveries.

Global cases update:

For the latest global data, follow this interactive map from Johns Hopkins University & Medicine.

Early on Monday morning, positive cases worldwide were more than 54.25 million, while deaths were more than 1.31 million.

The United States had the most cases in the world - more than 11 million, as well as the most deaths - more than 246 000.


Latest news:

HEALTH TIPS (as recommended by the NICD and WHO)

• Maintain physical distancing – stay at least one metre away from somebody who is coughing or sneezing

• Practise frequent hand-washing, especially after direct contact with ill people or their environment

• Avoid touching your eyes, nose and mouth, as your hands touch many surfaces and could potentially transfer the virus

• Practise respiratory hygiene – cover your mouth with your bent elbow or tissue when you cough or sneeze. Remember to dispose the tissue immediately after use.

Image credit: Getty Images

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