Category: COVID

Categories : COVIDTags :

As COVID Variants Dominate, Better Mask Use is Needed

On By ModernMedia

Evidence is accumulating that COVID is commonly transmitted through small aerosolised droplets emitted during regular speaking and breathing—a problem compounded by the enhanced contagiousness of variants such as 501Y.V2, the strain which dominates in South Africa.

Masks have become ubiquitous in the pandemic-struck world, and even fashionable, with many different types available. However, their effectiveness varies considerably from top-of-the-range N95 masks to a pulled-up shirt which offers very little protection.
“How well a mask works depends on two things: filtration and fit,” said Professor Linsey Marr, who studies airborne disease transmission at Virginia Tech .

“Good filtration removes as many particles as possible, and a good fit means that there are no leaks around the sides of your mask, where air—and viruses—can leak through,” she said, noting that even a small gap could result in a 50% reduction in effectiveness.

We do not recommend wearing more than two masks. Adding more layers proves diminishing returns and can compromise breathability. It must remain easy to breathe through the layers; otherwise, air is more likely to leak in around the sides of the mask.

Wearing a cloth mask over a surgical mask, or ‘double masking’ does improve effectiveness as it serves to tighten the surgical mask’s fit. Air escapes around the corners and edges of the mask, as anyone who has worn glasses and had them fog up in the cold can attest to.

While N95 masks are the best available, there are also equivalents such as KN95 or FFP2.

“They all provide a similar level of filtration, meaning protection of particles going in and out,” said Ranu Dhillon, a global health physician at Brigham and Women’s Hospital and Harvard Medical School. Dhillon is frustrated at the lack of transparency and education for the public about masks.

Health care workers, for example, get their masks tested for fit, something which could be also done by members of the public.

Donald Milton, a professor of environmental health at the University of Maryland, said that the key to understanding the COVID airborne transmission threat is to treat it like cigarette smoke. Ventilation helps, but if you have someone between you and an exhaust vent, then masks will definitely help.

Before the pandemic, Milton and Dhillon courted controversy by demonstrating that most viral transmission was in the form of small droplets emitted when speaking or breathing, and the contribution to transmission by coughing and sneezing was smaller than previously thought. The two researchers are hopeful that their findings will find their way into official COVID policy, and future research may even see masks becoming a common sight during peak flu seasons.

Source: Japan Times

Categories : COVIDTags :

Reckless to Discard AstraZeneca Vaccines, Says Prof Madhi

On By ModernMedia

Professor Shabir Madhi of Wits University says that it would be reckless to simply abandon South Africa’s stock of AstraZeneca vaccine doses, even after a small trial showed it to have minimal effect against the local variant.

One million doses of AstraZeneca vaccine had been scheduled for rollout, but that plan has been put on hold after preliminary results showed that it conferred minimal effectiveness against mild-to-moderate infections by the dominant 501Y.V2 strain in South Africa. 

Madhi said that scientists needed more time to go through the data, said Madhi.

“I think it would be highly reckless for us to discard the vaccine. We paid a high price for it and so the vaccines do have a role in protecting from severe disease. I think an important feature in all the vaccines is that generally, vaccines work much better in preventing severe disease.”

There is already a closing window of opportunity, since it was recently discovered that the first batch of one million doses received from the Serum Institute of India would be expiring in April.

Madhi said that there were other options to put the vaccine to good use.
“If we’re strategic in terms of the rollout, we might still be able to get the vaccine used, not two doses per individual but at least a single dose and we could possibly follow it up then with another vaccine and a few vaccines that might come online in the next two or three months.”

In an interview with the BBC, he said that the disappointing results of the trial had not been able to show the effectiveness against severe COVID, as the sample size was too small and too young, with an average age of 31, but that it might still have a protective effect in different age groups. “There’s still some hope that the AstraZeneca vaccine might well perform as well as the Johnson & Johnson vaccine in a different age group demographic that I address of severe disease,” he said.

Source: Eyewitness News

Categories : COVID General InterestTags :

Drone Company to Start New Rural Vaccine Delivery Service

On By ModernMedia

Zipline, a company that has made its name using drones to deliver medicines to remote locations in countries like Rwanda, has announced that it is to expand its capability to include all COVID vaccines.

In a press release, Zipline said that it is partnering with a COVID vaccine manufacturer, the identity of which was not disclosed, to add on the ability to deliver vaccines that require ultra cold temperatures in specialised refrigerated containers.

For remote rural locations, the Pfizer/BioNTech vaccine is not an option because of  its stringent temperature storage requirements of minus 70 degrees celsius. In such situations, the choice of COVID vaccines is limited to the more expensive Moderna vaccine, which still requires freezing temperatures, or vaccines like those from Johnsons & Johnson or AstraZeneca, which don’t have as high effectiveness but are able to be stored at normal refrigerator temperature ranges.

Zipline is planning to add these ultracold storage refrigerators at all of its drone bases. A clinic in its network would be able to request a few dozen doses of vaccine, and the company’s drones would be able to deliver it in a special refrigerated container.

Zipline operates fixed-wing, battery-powered drones that can make a round trip of up to 80 kilometres. Each base that the drones operate from can service an area of over 22 500 square kilometres, completely ignoring difficult terrain and lack of road access which may endanger drivers. A trip which could take hours in a 4 by 4 can be done in under an hour.
The drones can deliver a 1.75kg payload by parachute at a designated location, and return to base. Since the drone navigates by GPS, it can do so in a range of weather conditions, and by day or night.

Zipline CEO Keller Rinaudo said that his company wants to help rural areas that have been hard hit by COVID. “Where you live shouldn’t determine whether or not you get a COVID-19 vaccine,” he said in the release. “We can help health systems bypass infrastructure and supply chain challenges through instant delivery.”

Source: Bloomberg

Categories : COVIDTags :

UK to Look at Mixing of Different Vaccines

On By ModernMedia

The UK is launching a trial to explore the mixing of vaccines can be combined. Some, like Russia’s Sputnik vaccine, already combine two different types of vaccines, but these were specifically designed and tested to work together. 

Current guidance in the UK says that anyone who receives a Pfizer-BioNTech or Oxford-AstraZeneca vaccine dose should get the second dose of that same vaccine. Only in exceptional circumstances such as not knowing what vaccine was given will a different vaccine be administered.

The main aim was to enhance logistical flexibility. The Oxford/AstraZeneca, Johnson & Johnson and Novavax vaccines can all be stored at normal refrigerator temperatures, while the Moderna vaccine must be stored at -20C, within normal freezer range, and Pfizer/BioNTech’s vaccine needs an ultra-cold -70C. Not requiring a second dose of the same vaccine could ease up storage requirements. 

However, with previous vaccines, mixing different vaccine types worked and even strengthened their overall effectiveness. Some Ebola immunisation programmes, for example, combine two different vaccines to achieve greater protection.

The trial will comprise some 800 participants aged 50 or older, receiving a combination of Oxford/AstraZeneca and Pfizer/BioNTech in either order.

Some vaccines that work by using a virus to deliver the antigens, and there is some evidence to suggest that the immune system starts to focus on the viral delivery system instead of the antigen. Thus, combining vaccines will keep the immune system’s attention on the antigens.

Chief investigator, Prof Matthew Snape from the University of Oxford, said the “tremendously exciting study” would provide critical information for vaccine rollouts.

Animal studies have shown “a better antibody response with a mixed schedule rather than the straight schedule” of vaccine doses, he said.

“It will be really interesting to see if the different delivery methods actually could lead to an enhanced immune response [in humans],” he said, “or at least a response that’s as good as giving the straight schedule of the same doses”.

Source: BBC News

Categories : COVIDTags :

Viral Load Drives the Transmission of COVID

On By ModernMedia

Knowing what factors drive the transmission of COVID is crucial to informing schemes to contain and adapt to its spread.

There is abundant data on location and duration of exposure to COVID, but there is precious little on any other factors, the researchers noted.

The SARS-CoV-2 virus is detectable in respiratory tract samples 1-2 days before symptom onset, and can continue for several weeks afterward. But the detection of viral RNA is not necessarily related to infectiousness, and no studies had established the connection between viral load and COVID transmission, although viral load had been linked to COVID mortality.

The researchers used linked index cases of COVID to determine that viral load was the principle factor behind COVID transmission, and is the largest such study to date. This emphasises the need for initiating proper contact tracing.

The researchers conducted a post-hoc analysis of 314 cases during the initial COVID wave in Spain, of whom 90% (282) had at least one close contact, resulting in a total of 753 contacts. Viral load was the key indicator of COVID transmission.

The overall secondary attack rate (proportion of COVID-positive contacts) during the study period was 17%. However, this rate varied from 12% when the viral load of the index case was lower than 1×10⁶ copies per mL, to 24% when it was 1×10¹⁰ copies per mL or higher.

Running multivariate analyses, the researchers found no association between sex, age, diabetes, cardiovascular disease, or respiratory disease and the risk of or time to developing symptomatic COVID. There was a significant association of incubation time with initial viral load, increasing from five days among patients with a high viral load to seven days among participants with a low viral load.

The researchers wrote: “Taken together, our results indicate that the viral load, rather than symptoms, might be the predominant driver of transmission.”

They conclude that all cases should be considered potential transmitters of the virus. They also suggest viral load assessment in patients with large numbers of contacts, and risk stratification by time to symptom appearance based on viral load. 

Source: News-Medical.Net

Journal information: Marks M, et al. Transmission of COVID-19 in 282 clusters in Catalonia, Spain: a cohort study. The Lancet Infectious Disease, 2021. DOI: https://doi.org/10.1016/S1473-3099(20)30985-3, https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30985-3/fulltext

Categories : COVIDTags :

Pfizer Vaccine 90% Effective After a Single Dose

On By ModernMedia

A study from the University of East Anglia (UEA) reported that the Pfizer vaccine provides “very high” protection after a single dose.

The researchers drew on Israeli data, where the vaccine had been widely administered, and found that the vaccine was 90% effective at 21 days after the initial dose. This supports the plan that the UK and other nations have of delaying a second dose to achieve maximum coverage. However, they also noted that infection rates increased eight days after the first dose, which they attribute to people becoming less cautious as a result of the vaccination. The study is available on the medRxiv preprint server, and has not been peer reviewed, as it is a rapid response to the ongoing COVID pandemic.

Lead researcher and COVID expert Prof Paul Hunter, from UEA’s Norwich Medical School, said: “A second dose of the Pfizer vaccine would normally be given 21 days or more after the first to top up and lengthen the effect of the first dose.

“But here in the UK, the decision was made to delay the timing of the second injection until 12 weeks after the first.

“The logic behind this is to protect more people sooner and so reduce the total number of severe infections, hospitalisations, and deaths.

“But this decision caused criticism from some quarters due in part to a belief that a single injection may not give adequate immunity.”

Prof Hunter explains the motivation for the study was previous flawed research on the Pfizer vaccine, also using Israeli data. But the study did not consider effectiveness past day 18.

The researchers observed that case incidence rose up til day eight by which time it had doubled, then fell. Prof Hunter said: “We found that the vaccine effectiveness was still pretty much zero until about 14 days after people were vaccinated. But then after day 14 immunity rose gradually day by day to about 90 percent at day 21 and then didn’t improve any further. All the observed improvement was before any second injection.

“This shows that a single dose of vaccine is highly protective, although it can take up to 21 days to achieve this.”

Although the vaccine’s effectiveness beyond this is not known, it still supports the UK’s decision to space out vaccine doses, Prof Hunter concluded.

Source: Medical Xpress

Journal information: “Estimating the effectiveness of the Pfizer COVID-19 BNT162b2 vaccine after a single dose. A reanalysis of a study of ‘real-world’ vaccination outcomes from Israel” is published on the medRxiv pre-print server: www.medrxiv.org/content/10.110 … 021.02.01.21250957v1

Categories : COVID HospitalsTags :

UK Teen Awakens from 10 Month Coma, Unaware of Pandemic

On By ModernMedia

A British teenager who has been in a coma for 10 months, has awakened but is still largely unaware of the scale of the COVID pandemic. 

Joseph Flavill, 19, was hit by a car while walking on 1 March 2020, which was three weeks before the UK entered into its first national lockdown. Having suffered a traumatic brain injury, he has since been in a coma but is now making a slow recovery and is responsive. Ironically, he has caught COVID twice while in hospital but had recovered both times.

His aunt, Sally Flavill Smith, told the Guardian: “He won’t know anything about the pandemic as he’s been asleep for 10 months. His awareness is starting to improve now but we just don’t know what he knows.

“I just don’t know where to start with it. A year ago if someone had told me what was going to happen over the last year, I don’t think I would have believed it. I’ve got no idea how Joseph’s going to come to understand what we’ve all been through.”

He is now able to respond to commands, such as touching his left or right ear, respond with yes/no by blinking, and is able to smile.

His family had trained to explain in video calls why they can’t see him in person due to COVID restrictions, but had not tried to convey the scale of the pandemic. She says that they will try to explain it to him when they are able to visit him in person. His mother was able to see him in December, wearing full PPE, but he was not as aware as he is now. The family has put together a fundraiser to help his recovery.

Source: The Guardian

Categories : COVIDTags :

New Single-dose Intranasal Vaccine Shows Promise

On By ModernMedia

A new, single dose intranasal vaccine has shown ability to protect Macaques against COVID, as reported in a preprint article on bioRxiv. If it proves effective and safe in humans, it could be a radically effective and simple to administer vaccine against COVID.

Currently, most COVID vaccines are administered intramuscularly and require two doses. However, after immunisation, an infected person can still shed the virus from the upper airways because they do not have local or mucosal immunity, as demonstrated by intramuscular vaccination in non-human primates.

The SARS-CoV-2 virus enters the target the host cell by the spike (S) protein antigen locking on to the cell’s angiotensin-converting enzyme 2 (ACE2) receptor. Thus, the S protein is a critical target for vaccine development.The researchers developed the new vaccine uses a chimpanzee adenovirus which expresses the S protein (ChAd-SARS-CoV-2-S). The chimpanzee adenovirus (also used in the AstraZeneca vaccine) is ideal as an antigen carrier for vaccines as the prevalence of neutralising antibodies against it is low. 

In the researchers’ previous work, the vaccine had been administered intranasally to mice with expressed human ACE2 receptors, producing a detectable immune response. The researchers then moved experimentation on to macaques, administering a single intranasal dose of vaccine, followed by intranasal and intrabroncheal challenge with SARS-CoV-2.

A detectable immune response was detected by the presence of anti-S, anti-RBD, and neutralising antibodies, as well as T cell responses. Viral RNA loads measured by nasal swabs were lower in immunised animals, with only one having detectable virus presence, compared to four of six control animals. These results suggest that local infection is prevented, with reduced viral RNA levels and faster viral clearing. 

Infection was also measured in broncheal alveolar lavage fluid (BALF)At day seven, immunised animals showed lower viral DNA than controls, corresponding to increased neutralising antibody levels.

Administering the vaccine intranasally could allow protection of the local and surrounding tissues, while reducing disease severity and spread to others. However, the lack of severe pathologies in both sets of animals means that no conclusions can be drawn about the vaccine’s effectiveness in preventing against COVID.

Further research is required to compare the effects of intramuscular and intranasal administration of the vaccine, and the work is yet to be peer reviewed.

Source: News-Medical.Net

Journal information: Hassan, A. O. et al. (2021). A single intranasal dose of chimpanzee adenovirus-vectored vaccine protects against SARS-CoV-2 infection in rhesus macaques. bioRxiv preprint. doi: https://doi.org/10.1101/2021.01.26.428251. https://www.biorxiv.org/content/10.1101/2021.01.26.428251v1

Categories : COVIDTags :

Ramaphosa to Take Delivery of SA’s First Vaccine Doses

On By ModernMedia

President Cyril Ramaphosa will take delivery of the first million doses arrives in South Africa at OR Tambo airport on Monday.

Ramaphosa will be accompanied by Deputy President David Mabuza, Health Minister Zweli Mkhize and the High Commissioner of India. After the vaccine has been received, it will be taken to cold storage for and undergo technical processing and quality testing.

Acting spokesperson for the Presidency, Tyrone Seale, said: “The arrival of the fist consignment at OR Tambo International Airport marks the start of the vaccine roll-out, which President Ramaphosa describes as the largest and most complex logistical vaccine undertaking in South Africa’s history.”

The AstraZeneca doses were produced by the Serum Institute of India, and healthcare workers will be the first to be vaccinated, with essential workers second on the list. However, the Department of Health has suggested that politicians (who are classified as essential workers) may be the first to receive the vaccine, in order to reassure the public and encourage vaccine uptake. An additional 500 000 doses are to be delivered in February.

There are fears that current vaccines are less effective against the B1.351 “South African” variant. The Novovax vaccine has been shown to have slightly less than 50% effectiveness in South African trials, due to the variant and the prevalence of HIV in the population. Johnson & Johnson’s vaccine, which is set to be produced locally by Aspen, is around 57% effective in South Africa. These are about what is achieved with annual flu vaccines, which are 40-60% effective. The AstraZeneca AZD1222 vaccine developed in concert with Oxford University have been shown to be 70% effective in clinical trials, although this was prior to the widespread emergence of COVID variants. However, it is possible to adjust vaccines to to deal with the new variants, with Dr Anthony Fauci saying that this reduced vaccine effectiveness against variants is a “wake-up call”.

The Azstra Zeneca vaccine uses a non replicating viral vector to deliver genetic information to cells, instructing them to produce the spike protein of the SARS-CoV-2 virus to train the immune system to recognise it and build immunity. It requires two doses administered four weeks apart, and unlike many other vaccines, does not require storage at extremely cold temperatures – only requiring normal refrigeration at 2° to 8°C.

Source: Eyewitness News

Categories : COVIDTags : 1 Comment

Ivermectin Approved to Treat COVID in SA on Limited Basis

On By ModernMedia

Ivermectin, which has some reports of high effectiveness in limited studies, has received approval from the SA government to be used under strict control for compassionate use.  

Dr Boitumelo Semete-Makokotlela, head of the South African Health Products Regulatory Authority (SAHPRA), said that practitioners applying to use the drug will be considered case-by-case.

Ivermectin has a long history of use as an antiparasitic treatment in animals, while in humans it’s used as an anthelmintic drug that is usually indicated for filarial and resistant scabies infections. While the World Health Organization has suggested the drug has encouraging effects on coronavirus, although it hasn’t been properly evaluated yet.

“We absolutely share everyone’s desperation at this point,” said Helen Rees, SAHPRA chairwoman. “So the question about ivermectin and self-medication goes back to what everyone in the scientific community is saying. And that is, we don’t know if it works and we don’t know if it doesn’t work. That’s why we need to get data.”

Physicians in Zimbabwe are reportedly treating COVID with ivermectin in combination with silver nanoparticles – normally used as an algaecide – to great success.

Rees, however, warned South Africans that people self-medicating “need to be very careful because we don’t have any information about the quality of what you’re taking.”

Dr Semete-Makokotlela said that clear guidelines for the rollout would be given tomorrow. She added that SAHPRA granted the health department permission to distribute the Oxford/AstraZeneca COVID vaccine, the first one for SA. It is also currently reviewing applications from Johnson & Johnson and Pfizer, but has yet to receive an application from Moderna, she said.

Source: BusinessTech