Some areas see numbers rise after the government changes the way it records the location of a case.

The menstrual cycle, the pill and their potential impact on sporting performance have long been considered a taboo subject. Yet for most females who undertake any form of exercise or high-performance sport, there are a range of challenges that can affect their athletic performance, including from their menstrual cycle and their use of contraceptive pills.

But a historic lack of scientific research in these areas still means we have very limited knowledge of the specific effect that both have on athletic performance. However, what research we do have on these subjects shows both can have an impact on athletic performance – which may be especially important for elite athletes.

During the average menstrual cycle, levels of the sex hormones oestrogen and progesterone change throughout each phase. These hormonal fluctuations cause changes in body temperature, the storage and use of energy, and the ability of muscles to produce force.

The cycle is divided into three phases. Menses (days one to five of the cycle) is where both oestrogen and progesterone levels are low. This is followed by the follicular phase during which oestrogen concentration rises to a peak (between days 10-14). Immediately preceding is ovulation, where progesterone remains almost unchanged. Thereafter, during the luteal phase, the concentrations of both oestrogen and progesterone are high (days 19-24). If no implantation of a fertilised egg occurs, both oestrogen and progesterone levels fall, and the cycle recommences.

It’s the fluctuations in oestrogen and progesterone which are thought to have an impact on sporting performance. Research shows both oestrogen and progesterone promote the uptake and storage of muscle glycogen. Both hormones also change the ability to use this stored form of carbohydrate for energy – both during exercise and at rest.

Glycogen is the stored form of carbohydrate in the muscle which plays a significant role in supplying energy to the body during exercise. Use of muscle glycogen appears to be more proficient during the luteal phase, when oestrogen and progesterone are high. This suggests that during menses and the folicular phases exercise requires us to use more of our stored glycogen, so may cause more fatigue.

Another common aspect of the menstrual cycle is the fluctuation in body temperature, largely because progesterone induces heat production. Increased progesterone concentrations is associated with an increased core body temperature. When core temperature is raised, blood is directed to the skin in order to remove heat and lower internal temperature. However, this can compromise oxygen delivery to the muscles, resulting in greater perceived effort and potentially earlier onset of fatigue. The luteal phase in particular is characterised by higher core temperature and increased heart rate.

Several studies have also observed that muscular strength is lower during menses compared to the other phases. This time it’s oestrogen causing this effect. Indeed, a number of the key cellular structures involved in generating muscular force are sensitive to fluctuations in oestrogen. Low concentrations of oestrogen circulating during menses may make strength training feel harder, and fatigue likely to occur earlier. Some evidence also suggests that there’s both increased sensations of pain and exertion during the follicular phase as well, making exercise feel more challenging.

However, recent reviews have concluded that despite these biological responses, the impact on sporting performance seems to be minimal. But given that at the elite level differences between winning and losing are themselves minimal, this should potentially be taken into consideration.

The pill

Not only is the pill a common contraceptive method it’s also used by many women to alleviate symptoms of dysmenorrhoea (painful cramps) and menorrhagia (abnormal, heavy, or prolonged bleeding). Many athletes also use the pill to regulate and manipulate their cycles to coincide with training and competition schedules.

In general, pills work by downregulating the production of sex hormones through a constant release of low doses of synthetic oestrogen and progesterone. Throughout the so-called pseudo-cycle, the hormone concentrations for both oestrogen and progesterone stay at levels comparable to the menstruation phase of women who do not take the pill.

Recent research suggests that performance levels while taking the pill remain the same. However, thhere’s potentially a slightly negative impact of suppressing the ovarian hormones while taking the pill on athletic performance compared with non-pill users. This suggests that the consistently elevated concentrations of progesterone and oestrogen, as seen with a mono-phasic pill may impact on energy availability and use.

This could potentially impair both strength and endurance exercise performance. However, pill use (or non-use) should be judged on an individual basis, especially given that the benefits of taking the pill can outweigh possible performance detriments from taking it. But in general, the pill may have less overall impact on athletic performance.

However, researchers still know very little about the impact of the pill on athletic performance, including downsides, because the area is vastly under-researched. Currently, there’s also no research into the impact that other forms of contraception – such as injections, the coil and implants – have on athletic performance.

In the end, the impact a woman’s period or contraceptive use has on her performance is highly subjective. For example, former British tennis player Heather Watson exited the first round of the Australian Open in 2015 due to what she called “girl things” (“dizziness, nausea, low energy levels and spells of feeling light-headed”) – highlighting how the menstrual cycle is still a taboo topic. By contrast, when Paula Radcliffe first broke the marathon world record in Chicago in 2002, she was actually suffering period cramps in the final parts of the race.

But even in this day and age, scientific research on how periods and the pill affect athletic performance is lacking in both quantity and quality – meaning clear solutions and practical recommendations for those affected haven’t really been found yet.

Dan Gordon, Principal Lecturer Sport and Exercise Sciences, Anglia Ruskin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Dan Gordon, Anglia Ruskin University

African traditional medicine and its practices were prohibited under the pretext of witchcraft in South Africa by the British and later the apartheid government. This led to secrecy in the practice and a lack of infrastructural planning to support it.

As a result, traditional healthcare practices are largely informal and unregulated. This raises questions around accessibility and patient safety, as well as the accountability of healers. Traditional health practices make use of symbolic rituals and natural products, including local plants. They also follow certain cultural rules about privacy. And they require specific spatial qualities in terms of scale, sequencing, light and materials.

In 2007 the South African government gazetted the Traditional Health Practitioners Act to officially recognise the practice of traditional medicine. But little has been done to develop formal spaces for traditional healing practices – especially in an urban context. Most healers still practise in their houses where there is little privacy for patients and their families are exposed to ill people. Others use more private backrooms. But these spaces aren’t designed for the practice of traditional medicine.

The spaces where traditional medicine is practised are important because they assist with the healing process. These spaces play an indispensable role in helping patients get better. Different to biomedicine, African traditional healing is holistic: besides the patient’s symptoms it considers the person as a whole and their social relationships. During the consultation, landscapes, buildings and their elements, such as materials and plants, gain symbolic meaning to the patient, through their use by the healer. The setting, the herbal component and the dialogue with the healer provide a physical comfort and a sense of cultural belonging to the patient and all these components combined are responsible for the healing.

For this reason there’s a dire need for architectural design insight into the best qualities for spaces that could house these cultural rituals of healing. Guidelines are needed for the suitable design and construction of landscapes and buildings for traditional health practitioners in South Africa – in the same way as the country has guidelines for clinics and hospitals.

Proper facilities supported by well researched cultural principles for layout and design will go a long way to improving the image and perception of the practice of traditional medicine. Bringing together the perspectives of architectural design and the cultural use of medicinal plants, we are working on research which aims to develop guidelines for the design and construction of landscapes and spaces for traditional health practitioners in South Africa

Traditional healing in South Africa

Eighty percent of South Africans consult traditional healers and there are more than 200,000 traditional healers. Most of them are based in rural areas. Many South Africans still use traditional medicine for their primary healthcare needs. This is because traditional healthcare practitioners are often more accessible and affordable. They are familiar with the community and their cultural practices and beliefs.

Most rural villages in South Africa continue to have resident traditional healers. Some of these villages even have large traditional markets that remain functional, such as Mona Market in Nongoma, KwaZulu-Natal.

But traditional health practice isn’t relegated to rural areas only.

It is widely practised in major cities such as Durban and Johannesburg. Due to demand, some municipalities have donated infrastructure for the healers to practise and sell their traditional medicine. Examples of state-funded infrastructure include the Mai-Mai and Faraday markets in Johannesburg and Warwick Junction in Ethekwini, Durban. In the country’s capital, Pretoria, healers trade and consult freely in informal markets and a few small private businesses such as in Marabastad, near the city centre.

These markets are well established and attract considerable trade.But they are not ideal as they were initially designed for other purposes, such as horse stables in the case of Mai-Mai Market. They lack the basics needed for trade and hygiene, such as water, good lighting and ablutions. In addition, the spaces don’t reflect African cultural identity through their design and material qualities. These qualities, which include elements such as hierarchy, scale, order, use of light, colour and artefacts, are essential design considerations for the healing experience in traditional health practices.

Urban public spaces in South Africa were, and often still are, either Eurocentric in design or designed in a modernist international style. These spaces were not designed for African lifestyles and needs. This can be attributed to the legacy of apartheid ideals and spatial planning: to keep people apart on the basis of race and ethnicity and discourage the permanent presence of black people in cities.

Call for government commitment

Through strong commitment to funding and research, the governments of China, India and Japan have developed and institutionalised their respective traditional healthcare systems. In these countries, the practice and trade of traditional medicine and the design of its buildings and spaces are largely regulated.

This is in sharp contrast to South Africa and sub-Saharan Africa in general, where there is a lack of funding and research into traditional medicine. Since the adoption of the Traditional Health Practitioners Act in 2007, the South African government has not invested resources for funding and research to develop guidelines for the spaces of traditional healers.

It must be borne in mind that biomedicine used to be traditional medicine. But it developed through continued research and funding. The design guidelines of biomedicine facilities, including clinics and hospitals, have been well supported in South Africa. But traditional health practitioners are poorly regulated and thus undermined by the biomedical practitioners.

Properly designed facilities could provide comfortable access to traditional medicine for all members of society. Healers who have been previously marginalised deserve to practise in facilities that embody their world view and identity.

To take rightful ownership of the process, it is important for them to be heard and involved in the development of design guidelines.

John Molebatsi, PhD candidate, University of Pretoria; Christina Breed, Senior Lecturer, University of Pretoria, and Gary Ivan Stafford, Lecturer/researcher, University of Pretoria

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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John Molebatsi, Christina Breed and Gary Ivan Stafford

• Lying awake all night is known to have a negative impact on our mental health
• Researchers found that limited sleep may, however, be even worse
• Limited sleep activates fear in the brain, which can be problematic for people with fear-related disorders

Sleep deprivation is known for causing harm to our mental state, like disrupted learning and memory, which highlights the importance of getting enough sleep for memory retention. 

Fear conditioning is one of the reasons why memory and learning are important. Fear conditioning is a behavioural model which allows humans (and animals) to learn to predict aversive events. Recently, researchers found that getting only a restricted amount of sleep affects the brain’s ability to unlearn fear-related memories. 

Fear conditioning experiments

A team of researchers, led by Anne Germain (from the Department of Psychiatry at University of Pittsburgh), conducted a study which aimed to assess the impact of total and partial sleep loss on fear conditioning and extinction learning (a gradual decrease in conditioned response) in the brain.

The experiment was conducted in a sleep laboratory and involved 150 healthy adults who were divided into three groups: one-third who got to sleep normally throughout the night, one-third who slept only half the night and a third who did not sleep at all.

One of the co-authors, Dr Pace-Schott, explains: “Our team used a three-phase experimental model for the acquisition and overcoming of fearful memories while their brains were scanned using functional magnetic resonance imaging.”

In order to condition participants, they were shown three colours of which two were accompanied by mild shocks. After conditioning, participants partook in the fear extinction part of the experiment, where only one of the colours was shown without any shock. This was done to show participants that it was now safe. 

In the final part of the experiment, researchers examined the brain activity of the subjects when they were presented with the colours they were shown earlier.

Limited sleep worse than no sleep

In people who got normal sleep, brain imaging showed that areas responsible for emotional regulation were activated. Conversely, in people who got restricted sleep, brain imaging showed the least activity in the area of the brain that controls emotion, and that areas associated with fear were triggered instead. 

Interestingly, brain activity in people who were sleep-deprived looked similar to those who were well-rested. This finding indicates that being sleep-deprived may be better than sleeping for a limited time, especially in those who suffer from fear-related disorders such as anxiety and posttraumatic stress disorder. 

Researchers also warned that individuals in professions that are often paired with limited sleep – like medical and military staff – should be aware of the psychological effects of restricted sleep.

Compiled by Virginia Van Wyk

• Many people who work from home regularly engage in video calls 
• Some of these people are unhappy with their appearance on video calls
• This has led to an increase in the number of individuals seeking plastic surgery to improve their looks

A study has revealed that many people are looking into getting plastic surgery because of what they look like on their Zoom video calls.

Many people continue to work from home due to the Covid-19 pandemic and engage in regular video conferencing meetings on various call platforms.

Researchers discovered a recent surge in plastic surgery procedures – and they concluded that people are going under the knife because they are unhappy with their appearance on video calls.

Patients were particularly concerned about their noses, acne, and wrinkles.

Obsession with appearance

Dr Benjamin Marcus, an author of another study that investigated self-observation, self-criticism and narcissism commented on the results of the study: “The Covid-19 pandemic has radically changed the frequency with which we are confronted with our own image. The shift to online work, learning, and even socialising has dramatically increased the time we have to observe ourselves.”

The study was published in the journal Facial Plastic Surgery and Aesthetic Medicine.

READ | ‘Daddy-Do-Overs’: Men increasingly getting plastic surgery

Researchers also noticed that “hair loss” could also be a reason behind the surge in plastic surgery. The role played by hair loss and acne could be attributed to anxiety and depression, which have seen a big increase during periods of lockdown and quarantine.

In a statement, Dr Arianne Shadi Kourosh, along with her co-authors, said, “A life disproportionately spent on Zoom may trigger a self-critical comparative response that leads people to rush to their physicians for treatments they may not have considered before confronting a video screen – a new phenomenon called ‘Zoom Dysmorphia’.”

The phenomenon of Zoom Dysmorphia has been developing for a while. In an Allure article, which looked into plastic surgery during the pandemic, Jessica Weiser – a dermatologist in New York City – noted that people had started finding fault with their appearance on video even before the pandemic.

“No one has ever really looked at themselves in this way – for this long, or this frequently – and I think that’s driving a lot of the demand,” Jessica Weiser told Allure.

‘Snapchat Dysmorphia’

This isn’t the first time that the camera on electronic devices has been a catalyst for some users to become severely self-conscious about their appearance.

A few years ago there was speculation that, following the creation of the social media platform Snapchat, “Snapchat Dysmorphia” became an issue.

A study was conducted to determine if Snapchat Dysmorphia was a real issue.

The research indicates that plastic surgeons receive numerous requests for procedures to recreate the “filtered” appearance created by the social media platform.

The conclusion of the study was that these patients did not require plastic surgery, but rather needed psychological and mental health interventions.

WATCH | How plastic surgery has evolved

^{Image credit: Chris Montgomery, Unsplash}

Compiled by Stefni Herbert

• In early results from a human trial, Moderna’s Covid-19 vaccine candidate was shown to be 94.5% effective.
• Scientists say from the detailed findings released, it may have the edge over another candidate which also shows huge promise.
• Approval for this type of vaccine – an mRNA vaccine – has never been granted before, but the early results are a step in the right direction.

Drugmaker Moderna announced on Monday that its Covid-19 vaccine candidate, named mRNA-1273, was 94.5% effective, based on an early look at the results from its 30 000-person ongoing clinical trial.

The news arrived not long after similar results announced by Pfizer last week, and add to growing confidence that vaccines will help fight the pandemic and might be the best chance for the world to return to normal.

Participants in the trial were randomly given a two-dose regimen of either Moderna’s experimental shot or placebo (saltwater) injections. The company’s announcement states that their first interim analysis was based on the first 95 participants to develop Covid-19.

According to the data, there were 11 cases of severe Covid-19 in the trial, but none happened in participants who were immunised.

Moderna says its next step is to seek regulatory approval in the coming weeks for the use of the vaccine in the US. It expects to have 20 million doses available in the country and “remains on track to manufacture 500 million to 1 billion doses globally in 2021”.

What scientists are saying

Professor Thomas Scriba, deputy director of immunology and laboratory director at the South African Tuberculosis Vaccine Initiative, University of Cape Town, told Health24 Moderna’s results are very similar to that of Pfizer’s, and echoed his previous comments on the latter’s vaccine candidate.

“This is clearly an important and very positive step in a chain of many steps that need to be taken before vaccine vials are available in pharmacies and clinics.

“It is great that two vaccine candidates have shown such high levels of efficacy in interim analyses because the burden of proof from two independent sources is growing. Of course, the same limitations raised in my previous comments still stand – these are results shared is a press statement from a very short period after vaccination.

“The news that the mRNA-1273 Covid-19 vaccine candidate by Moderna is stable for 30 days at 2-8 degrees Celsius and for up to 6 months at -20 degrees Celsius is very important and good news, since these are the kind of transport and storage conditions required for many existing medical products (so they are already in place in many settings).

“Distribution and delivery of a vaccine to those who need it will be easier to achieve under these conditions,” Scriba said.

Some experts contacted by Reuters raised the point that the findings reported on Monday with the Moderna vaccine candidate are more detailed.

Professor Bodo Plachter, deputy director of the Institute of Virology at Mainz University Teaching Hospital in Germany, said: “Moderna has the advantage (over Pfizer) that they can already provide detailed findings on aspects such as severe disease, age and side effects.

“The question remains: What will protection look like after three, six or 12 months. It is fair to assume that it will last at least a year but we can’t be sure at this point.

“The side effects are within a range that would be expected of many other vaccines, such as shingles vaccine Shingrix.”

The severe disease aspect was echoed by Eleanor Riley, professor of immunology and infectious disease at the University of Edinburgh.

She told Reuters: “Although the numbers are small, this trial also gives an indication that vaccination is effective in older and BAME individuals and prevents severe disease, all of which are key to allowing the world to start opening up again.

“The absolute prerequisite for a Covid-19 vaccine is that it stops people becoming ill enough to require hospital treatment and stops people dying. The preliminary data reported here suggest that this vaccine – and by extension, the Pfizer/BioNtech vaccine – will achieve this goal.

“The safety data also look promising. The side effects of vaccination appear to be in line with those typically seen for other adult vaccinations, including the seasonal influenza vaccination which is administered in many millions of doses every year.

“One important unknown is whether this vaccine, or any of the vaccines currently in trials, prevents disease transmission.

“It is likely that vaccines that prevent symptomatic disease will reduce the duration and level of infectiousness, and thus reduce transmission, but we don’t yet know if this effect will be large enough to make any meaningful difference to the spread of the virus within communities.

“But, overall, this is excellent news. Having more than one source of an effective vaccine will increase the global supply and, with luck, help us all to get back to something like normal sometime in 2021.”

Very good news

Most scientists agreed that the news was encouraging, especially on the back of the Pfizer announcement last week.

Professor Trudie Lang said: “It is very good news indeed to see another vaccine coming through with similar efficacy results as were reported last week from Pfizer. This is also an interim analysis, which means that there were enough cases within the vaccinated volunteers to give statistical significance and allow the team to break the blind to determine who had the active vaccine and who had placebo.

“Here they found that of 95 cases of Covid, 90 had received the placebo and five the active vaccine. These early results suggest that there was a representation across different age groups and diverse communities in the protected group. This is really encouraging and it further demonstrates that a vaccine for Covid is a real probability and that having more than one supplier should help assure better and more equitable global availability.

“This vaccine is also an mRNA vaccine, so many of the same questions remain as we have been discussing with the Pfizer vaccine and these will be looked at carefully by the regulators.”

Professor Lang is the director of The Global Health Network, Nuffield Department of Medicine, at the University of Oxford.

Much more data needed

“This announcement from Moderna is a further encouragement that vaccines will be found to not only have an acceptable efficacy, but an efficacy that is much greater than we had anticipated. This press release is more specific than that of others, in that it confirms the numbers in each group, which was able to be guessed at but to have it confirmed is helpful,” Professor Stephen Evans told Reuters.

Evans, professor of pharmacoepidemiology at the London School of Hygiene and Tropical Medicine, added: “The range of minor adverse effects reported are unsurprising and typical of almost any vaccine. These reactions tend to be local to where the injection was given and are rarely long-lasting or severe.

“Although they reported efficacy being over 94%, there is statistical uncertainty in this; but based on these data, the likely efficacy will be better than 85% which would be greater than most scientists would have expected.

“This is the first study to report on severe cases and, while uncertainty remains, the finding of no severe cases with the vaccine and 11 cases with placebo is very strong evidence that the vaccine prevents severe as well as mild disease. It is likely that convincing evidence in respect to deaths will probably only be obtained when the vaccine is in use.

“A wide range of people with illnesses and from minority groups were included in the trials as well as substantial numbers of older patients. We will need much more data and a full report or publication to see if the benefit is consistent across all groups, notably the elderly, but this is definitely encouraging progress.”

Peter Openshaw, professor of experimental medicine at Imperial College London, said more complete details were needed but the announcement added to a general feeling of optimism.

“This news from Moderna is tremendously exciting and considerably boosts optimism that we will have a choice of good vaccines in the next few months.

“This latest press release is based on a study of 30 000 US adults, including many high-risk or elderly persons. This gives us confidence that the results are relevant in the people who are most at risk of Covid-19 and in most need of the vaccines.

“Moderna have also announced that the vaccine can be kept in a conventional freezer (-20 degrees Celsius) for up to 6 months, and that once thawed the vaccine can be kept for up to 30 days at standard refrigerator (2 to 8 degrees centigrade). This makes the vaccine much easier to deliver.

“In terms of side effects, news is also quite good. The first dose caused injection site pain in about 3% of people; the second dose was associated with transient generalised symptoms in about 10% of people with fatigue, muscle aches and flu-like symptoms.

“This seems to indicate that they got the dose about right with acceptable adverse events. These effects are what we would expect with a vaccine that is working and inducing a good immune response.

“We need more complete details than we have in this press release, but this announcement adds to the general feeling of optimism about vaccines for Covid-19. What we still don’t know is how long any protective immunity may last. For that, we will need to wait.”

Pfizer first to announce 90%-plus efficacy

Last week, drug maker Pfizer said data from their Phase 3 experimental Covid-19 vaccine, BNT162b2, showed it was 90% effective in preventing infections in volunteers, Health24 reported.

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”.

mRNA vaccines

Moderna and Pfizer’s vaccines both use messenger RNA, or mRNA, technology that is designed to trigger an immune response without using pathogens, such as actual virus particles.

This is done by injecting part of the coronavirus’ genetic code into the body, which then starts making viral proteins (but not the whole virus).

Should the person who received the vaccine encounter the virus, their antibodies and T-cells (which acts as “natural killers”) will therefore be triggered to fight it, thanks to the viral proteins which trained the body’s immune system to attack the virus.

Moderna explains that mRNA medicines essentially “instruct a patient’s own cells to produce proteins that could prevent, treat or cure disease”.

mRNA vaccines still need to be approved

While many studies of mRNA vaccines have taken place, none have been approved before – but the promising early results from Phase 3 trials for both candidates, as well as both being above 90% effective, put them in a good position.

“If mRNA vaccines against Covid-19 gain regulatory approval, this will be a huge validation of the RNA vaccine production platform technology,” Zoltan Kis, a research associate at The Future Vaccine Manufacturing hub, at Imperial College in London, told Reuters.

“Using this technology, vaccine candidates can be produced substantially faster in the future to combat virtually any infectious disease, by producing vaccines against both existing pathogens and future, currently unknown pathogens.

“Vaccine candidates can be produced against virtually any disease, because this is a platform technology, meaning that the production process, the purification processes and the formulation processes can remain the same no matter what vaccine or vaccine candidate is produced.

“This is a huge advantage in terms of the speed at which vaccine candidates can be developed and produced in the future.

“In the case of conventional vaccine production technologies, each vaccine required the development of a new production process, whereas in the case of the RNA vaccine production platform technology one process can produce vaccines and vaccine candidates against virtually any disease.”

What’s next?

This is still early data as both Pfizer and Moderna announced their trial findings in news releases. Therefore, as Scriba explained, detailed data that will allow outside experts to evaluate their claims (peer-reviewed journals) have yet to occur, so the results cannot be considered conclusive.

More than this, the trials are still ongoing and additional data may affect results.

Logistical challenges

If and when a vaccine becomes available to the public, there are many logistical issues to consider.

Scriba previously explained that once a vaccine is licenced for human use by regulators, it would need to be manufactured in large volumes, and distribution networks needed to be established and vaccination programmes would have to be put in place to deliver the vaccine to those who needed it.

“These are all non-trivial endeavours. We have had highly efficacious vaccines for a number of deadly diseases for decades and yet these diseases are still causing many deaths and cases of disease because these vaccines do not reach all those who need them.

“This result is clearly an important and very positive first step in a chain of many steps that need to be taken before vaccine vials are available in pharmacies and clinics,” Scriba said.

Additional reporting by Bhekisisa also notes that ensuring that a potential Covid-19 vaccine gets to people who need it – and is effective once they get it – will be challenging in the case of Pfizer’s vaccine, for example, especially for countries like South Africa. 

This is because Pfizer’s vaccine needs to be stored below freezing temperatures (minus 70 degrees Celsius).

Moderna said its candidate could be stored at a standard temperature of between two and eight degrees Celsius for up to 30 days – compared to its shelf life of six months when kept frozen. Despite this revised storage temperature, the jab still needs to be shipped and transported at minus 20 degrees Celsius.

Director of Vaccines for Africa at the University of Cape Town, Gregory Hussey, told Bhekisisa that except for a few of the ultra-cold freezers at large research institutions, such as the National Institute for Communicable Diseases (NICD), SA is unlikely to be able to afford to buy enough of these freezers (which cost between R150 000 and R235 000 each) to be able to make the vaccine available at community health centres or clinics, or pay for the cold chain systems that are necessary to maintain the vaccines.

South Africa has also not yet managed to secure any doses of candidate vaccines from Pfizer or any other manufacturer, Spotlight recently reported, adding that the country also missed the first deadline to commit to COVAX – an initiative co-lead by the World Health Organisation that aims to ensure developing countries get access to Covid-19 vaccines.

However, spokesman for the Department of Health, Popo Maja, confirmed to Spotlight that although SA had not concluded any vaccine deal, negotiations with manufacturers and COVAX are underway.

What about other vaccines?

While Pfizer and Moderna were the first to announce early results on large clinical trials, the World Health Organization’s latest draft landscape of Covid-19 vaccine candidates, dated 12 November, indicates that there are over 40 other candidates in the earlier stages of testing.

Another frontrunner is Johnson & Johnson’s Ad26.COV2.S vaccine, which has already commenced its Phase 3 ENSEMBLE trial.

The company announced on Monday that it launched a new late-stage trial in Britain to test a two-dose regimen of their experimental vaccine among thousands of volunteers, Reuters reported.

This trial will run in parallel with its 60 000-person global trial of a single shot of the vaccine, which was launched in September, and is also currently being trialled in South Africa.

*Additional reporting by Reuters, Bhekisisa, and Spotlight.

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

READ | Cold truth: South Africa won’t be able to store these Covid vaccines. Here’s why.

READ | Leading Covid-19 vaccine candidate to be manufactured in SA

^{Image: Getty/Tetra Images}

Compiled by Zakiyah Ebrahim and Bevan Lakay

• Face masks are strongly recommended to prevent the transmission of the coronavirus 
• However, a recent study showed that masks with exhalation valves do not slow the spread of the virus
• The researcher hopes the evidence will encourage people to wear face masks without valves

The Covid-19 pandemic has brought in its wake the compulsory use of face masks as they help to limit the spread of SARS-CoV-2.

Masks with exhalation valves, however, do not slow the spread of the virus, a researcher from the National Institute of Standards and Technology (NIST) has found.

The videos, which show airflow patterns through masks with and without exhalation valves, were created by NIST research engineer Matthew Staymates and were published, along with an accompanying research article, in the journal Physics of Fluids.

“When you compare the videos side by side, the difference is striking,” Staymates said in a news release by NIST.

“These videos show how the valves allow air to leave the mask without filtering it, which defeats the purpose of the mask.”

What is the purpose of masks with exhalation valves?

Exhalation valves make breathing more comfortable for the wearer. This type of mask is commonly worn by construction workers exposed to huge amounts of dust, or by hospital workers.

However, in the context of the pandemic, the Centers for Disease Control and Prevention (CDC) advises people to wear face masks that protect people other than the wearer. This is especially important for those who don’t display symptoms, as studies have consistently shown how asymptomatic cases are driving the spread of the virus.

“I don’t wear a mask to protect myself. I wear it to protect my neighbour, because I might be asymptomatic and spread the virus without even knowing it,” Staymates said. “But if I’m wearing a mask with a valve on it, I’m not helping.”

Staymates, who is an expert in flow visualisation techniques (which involves capturing the movement of air on camera), recently turned his expertise toward face masks to help develop novel ways to measure and improve their performance.

How the study was done

Staymates created two videos using different flow visualisation techniques. The first video used a schlieren imaging system, which causes differences in air density to show up on camera as patterns of shadow and light.

This video only shows the movement of the air itself, not the movement of exhaled droplets in the air.

On the left in this video, Staymates can be seen wearing an N95 respirator mask with a valve. This mask allows exhaled air to stream into the environment unfiltered.

On the right, there is no valve, and the air passes through the mask, which filters out most of the droplets.

The second video

Staymates created the second video using a light-scattering technique.

For this video, he built an apparatus that emits air at the same velocity and tempo as a resting adult. He then connected the device to a mannequin.

In contrast to the schlieren video, the video shows the movement of droplets in the air. On the left, droplets can be seen to escape unfiltered through the valve of an N95 mask.

In the middle, there is no valve and no breath is visible because the mask has filtered out the droplets. On the right, no mask is worn.

Staymates explained that using a mannequin and a mechanical breathing apparatus allowed him to observe airflow patterns while holding steady the breathing rate, air pressure and other variables.

More than one type of valve mask on the market

Staymates cautioned that different types of valved masks are available and may exhibit different results, and that his study involved only one type of this mask.

He also explained that masks that do not include valves, but that are not tight-fitting will allow some air to escape around the mask rather than filtering through it, which can also compromise the performance of the mask.

However, the main effect of valves is visible in the videos of this study, and Staymates hopes it will help people to understand why face masks meant to slow the spread of the new coronavirus should not have valves.

^{Image: Getty/Svetlana-Cherruty}

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Compiled by Zakiyah Ebrahim

• Recently published research reveals yet another reason why Covid-19 seems to spare young children
• In the study, researchers found that children have lower levels of an enzyme that the virus needs to invade cells in the lung
• Drugs that block the enzyme are currently being tested for Covid-19 treatment

Experts have found that children are mostly spared from the effects of Covid-19 – caused by SARS-CoV-2 – and if infected, often present with only mild symptoms.

Some studies have suggested that children’s lung physiology and immune function could serve as protection, while others have suggested that their blood vessels are better able to withstand a viral attack.

In a newly published study, a team of researchers from Vanderbilt University Medical Center (VUMC) in Nashville, Tennessee and their colleagues found another key reason why Covid-19 spares younger children.

According to their findings, published in the Journal of Clinical Investigation, children have lower levels of an enzyme (or co-receptor) that SARS-CoV-2 needs to invade airway epithelial cells in the lungs.

“Our study provides a biologic rationale for why particularly infants and very young children seem to be less likely to either get infected or to have severe disease symptoms,” Jennifer Sucre, MD, assistant professor of Pediatrics (Neonatology), who led the research with Jonathan Kropski, MD, assistant professor of Medicine, said in a news release published in May, when the study was posted online by the preprint server bioRxiv.

The results also support existing efforts to block the enzyme to potentially treat or prevent Covid-19 in older people, the authors noted.

TMPRSS2’s role in shielding children

The enzyme, type II transmembrane serine protease (TMPRSS2), plays a critical role in SARS-CoV-2 infection, in that it enables the virus to fuse into the cell membrane and “break into” the cell, ultimately hijacking the cell’s genetic material to make copies of its RNA.

Sucre and Kropski considered whether TMPRSS2 plays a role in severe Covid-19 cases observed in older people compared to children.

“Our research has always focused on understanding lung development and how infant lungs differ from adult lungs in their vulnerability to injury,” Sucre said. “In this study, we actually took the opposite approach, and were able to see how the developing lung by its differences is protected from SARS-CoV-2 infection.”

Using a technique called single-cell RNA-sequencing, the research team then built a dataset on lung development in mice, which can detect the expression of genes in individual cells of tissues, such as the lung.

Through this method, they were able to track the expression of genes known to be involved in the body’s response to Covid-19 over time.

More TMPRSS2 found in older adults

They found that while the gene for angiotensin-converting enzyme 2s, called ACE2 (the receptors that allow the virus to enter the body’s cells) was expressed at low levels in the lungs of mice. “TMPRSS2 stood out as having a really striking trajectory of increased expression during development,” Schuler said.

Together with VUMC pathologists, the researchers obtained and analysed human lung specimens collected from donors of different ages, and confirmed a similar trajectory in TMPRSS2 expression to what they’d found in mice.

“What we found is that expression of (TMPRSS2) goes up significantly with ageing, and we see that at the level of the gene and at the level of the protein,” Sucre said.

“We see a lot more TMPRSS2 in older individuals, in both humans and mice.”

Enzyme also linked to prostate cancer

The researchers wrote that TMPRSS2 is also well known for its role in the development of prostate cancer.

Drugs that block the enzyme, and which have already been approved for the treatment of advanced prostate cancer, are currently being tested clinically as potential treatments for Covid-19 as well.

“We do think TMPRSS2 could be an attractive target both in treatment and potentially as a prophylaxis (preventing infection) for people at high risk of Covid exposure,” Sucre said.

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READ | More scientific reasons why children are largely sheltered from Covid-19

^{Image: Getty/Volanthevist}

Compiled by Zakiyah Ebrahim

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