Category: COVID

Categories : COVID VaccinesTags :

Mechanism Behind AstraZeneca and J&J Vaccine Blood Clots Found

On By ModernMedia
A cloud of platelet factor 4 proteins interacting with the electrostatic surface of the Oxford vaccine, as seen through the computational microscope.
Credit: Chun Kit Chan, Arizona State University

An international team of scientists believe they may have found a molecular mechanism behind the extremely rare blood clots linked to adenovirus vaccines.

Scientists led by a team from Arizona State University, Cardiff University and others worked with AstraZeneca to investigate vaccine-induced immune thrombotic thrombocytopenia (VITT), also known as thrombosis with thrombocytopenia syndrome (TTS), a life-threatening condition seen in a very small number of people after receiving the Oxford-AstraZeneca or Johnson & Johnson vaccines.

“The mechanism which results in this condition, termed vaccine-induced immune thrombotic thrombocytopenia (VITT), was unknown,” said Abhishek Singharoy, an Arizona State University scientist and corresponding author of the study who teamed up to lead an international effort to tease out the details. 

Together, the team worked to solve the structural biology of the vaccine, and see the molecular details that may be at play, utilising state-of-the cryo-EM technology to analyse the AstraZeneca vaccine in minute detail. They sought to understand whether the ultra-rare side effect could be linked to the viral vector which is used in many vaccines, including those from Oxford/AstraZeneca and Johnson & Johnson.

Their findings suggest it is the viral vector – in this case, an adenovirus used to shuttle the coronavirus’ genetic material into cells – and the way it binds to platelet factor 4 (PF4) once injected that could be the potential mechanism.

In very rare cases, the scientists suggest, the viral vector may enter the bloodstream and bind to PF4, where the immune system then views this complex as foreign. They believe this misplaced immunity could result in the release of antibodies against PF4, which bind to and activate platelets, leading to clustering and blood clotting.

“It’s really critical to fully investigate the vector-host interactions of the vaccine at a mechanistic level,” said Singharoy. “This will assist in understanding both how the vaccine generates immunity, and how it may lead to any rare adverse events, such as VITT.”

Their findings were published in Science Advances.

Adenovirus expert Professor Alan Parker said: “VITT only happens in extremely rare cases because a chain of complex events needs to take place to trigger this ultra-rare side effect. Our data confirms PF4 can bind to adenoviruses, an important step in unravelling the mechanism underlying VITT. Establishing a mechanism could help to prevent and treat this disorder.”

“We hope our findings can be used to better understand the rare side effects of these new vaccines – and potentially to design new and improved vaccines to turn the tide on this global pandemic.”

The AstraZeneca and Johnson & Johnson vaccines both use an adenovirus to carry SARS-CoV-2 Spike proteins to trigger an immune response.

Since VITT was seen in both vaccines, scientists wondered whether the viral vector was involved. Additionally, neither the Moderna nor Pfizer vaccines, both mRNA vaccines, showed this effect.

Using cryo-EM technology to flash-freeze preparations of ChAdOx1, the adenovirus used in the AstraZeneca vaccine, they produce microscopic images of the vaccine components.

They were then able to view the viral capsid structure and other critical proteins that allow entry of the virus into the cell.

In particular, the team outlined the details for the structure and receptor of ChAdOx1, which is adapted from chimpanzee adenovirus Y25 – and how it interacts with PF4. They believe it is this specific interaction – and how it is then presented to the immune system – that could cuase the immune system to see it as foreign and release antibodies against this self-protein.

The research team also used computational models to show that one of the ways the two molecules tightly bind is via electrostatic interactions. The group showed that ChAdOx1 is mostly electronegative, attracting other positively charged molecules to its surface.

First author Dr Alexander Baker said: “We found that ChAdOx1 has a strong negative charge. This means the viral vector can act like a magnet and attract proteins with the opposite, positive charge, like PF4.” Baker is a member of ASU’s Biodesign Center for Applied Structural Discovery and an Honorary Research Fellow at Cardiff University School of Medicine.

“We then found that PF4 is just the right size and shape that when it gets close to ChAdOx1 it could bind in between the negatively charged parts of ChAdOx1’s surface, called hexons.”

The research team are hopeful that armed with a better understanding of what may be causing rare VITT they can provide further insights into how vaccines and other therapies, which rely on the same technology, might be altered in the development of the next generation vaccines and therapies.

“With a better understanding of the mechanism by which PF4 and adenoviruses interact there is an opportunity to engineer the shell of the vaccine, the capsid, to prevent this interaction with PF4. Modifying ChAdOx1 to reduce the negative charge may reduce the chance of causing thrombosis with thrombocytopenia syndrome,” said Baker.

The team likened it to the ‘two birds, one stone’ effect. The key contacts of individual amino acids that are essential to the capsid protein’s proteins interaction with PF4 can removed or substituted.

“The modification of the ChAdOx1 hexons to reduce their electronegativity may solve two problems simultaneously: reduce the propensity to cause VITT to even lower levels, and reduce the levels of pre-existing immunity, thus helping to maximize the opportunity to induce robust immune responses, said Singharoy.”

Source: EurekAlert!

Categories : COVIDTags :

Paxlovid Ramped up and No ‘Red Flags’ for Omicron Yet

On By ModernMedia
Image by Quicknews

In the face of a renewed global surge in COVID cases, Pfizer has ramped up production of Paxlovid, even while the efficacy of Merck’s molnupiravir appears to be less than believed.

Pfizer is now expecting to make 80 million courses of Paxlovid by the end of 2022, Pfizer CEO Albert Bourla told CNBC, a significant increase over its earlier planned capacity of 50 million courses.

This news came after Merck reported the risk reduction in hospitalisation and death from its COVID antiviral, molnupiravir, fell from 50% in the interim analysis to 30% in the final analysis. The reduction came after results were updated with participants that became evaluable after the interim analysis. This drop has led to predictions of increased demand for Paxlovid, which has shown an 89% risk reduction in outpatients.

The increase in production comes just in time to fight the Omicron variant, for which South Africa is now better prepared, according to experts.

‘No red flags’
According to Professor Salim Abdool Karim, director of the Centre for the Aids Programme of Research in South Africa, the numbers appear to be on the rise across all continents, but as yet there are “no red flags” he said.

Omicron has been identified by South African scientists as a major driver of the spike in cases in Gauteng.

“We have been amazed at how fast the numbers are going up,” he said. “But we were not caught with our pants down. We expected and prepared for a fourth wave. [The scientists] gave us the best fighting chance by giving us information early. We didn’t know exactly when it would come and what it would look like,” Prof Karim said, speaking to the Daily Maverick.

While a number of mutations enable the variant to escape immunity, a clear picture of Omicron’s nature won’t emerge for two to four weeks, he cautioned.

Speaking about travel bans imposed on South Africa by Mauritius, Rwanda, Egypt and the Seychelles, President Cyril Ramaphosa said ahead of a West African tour: “I am concerned. Out of due respect to them, they have their own reasons. We would like to have a discussion with them in a way we prefer that they do not react like our former colonisers who are very quick to close Africa down,” Ramaphosa told journalists.

EU accelerates child vaccinations
EU President von der Leyen has said that vaccines for children aged five to 11 will be available in the bloc by December 13, a week ahead of schedule and that she is pushing for the consideration of mandatory vaccination. This comes amidst news that Omicron was detected in the Netherlands before its first detection in South Africa. Meanwhile, in Asia, South Korea has reported its first five cases of Omicron.

Categories : COVID HospitalsTags :

How One Hospital Met the COVID Surge Head-on

On By ModernMedia
Photo by Artem Podrez on Unsplash

Since March of 2020, the COVID pandemic has put an unprecedented strain on hospitals as large surges of intensive care unit patients overwhelmed hospitals. To meet this challenge, Beth Israel Deaconess Medical Center (BIDMC) expanded ICU capacity by 93% and maintained surge conditions during the nine weeks in the first quarter of 2020.

In a pair of papers and a guest editorial published in Dimensions of Critical Care Nursing, a team of nurse-scientists at Beth Israel Deaconess Medical Center (BIDMC) report on almost doubling the hospital’s ICU capacity; identifying, training and redeploying staff; and developing and implementing a proning team to manage patients with acute respiratory distress syndrome during the first COVID surge.

“As COVID was sweeping through the nation, we at BIDMC were preparing for the projected influx of highly infectious, critically ill patients,” said lead author Sharon C. O’Donoghue, DNP, RN, a nurse specialist in the medical intensive care units at BIDMC. “It rapidly became apparent that a plan for the arrival of highly infectious critically ill patients as well as a strategy for adequate staffing protecting employees and assuring the public that this could be managed successfully were needed.”

After setting up a hospital incident command structure to clearly define roles, open up lines of communication and develop surge plans, BIDMC’s leadership began planning for the impending influx of COVID patients in February 2020.

BIDMC – a 673 licensed bed teaching hospital affiliated with Harvard Medical School – has nine specialty ICUs located on two campuses for a total of 77 ICU beds. Informed by an epidemic surge drill conducted at BIDMC in 2012, it was determined that the trigger to open extra ICU space would be when 70 ICU beds were occupied. When this milestone was met on March 31, 2020, departmental personnel had a 12-hour window to convert two 36-bed medical-surgical units into additional ICU space, providing an additional 72 beds.

“Because the medical-surgical environment is not designed to deliver an ICU level of care, many modifications needed to be made and the need for distancing only added to the difficulties,” said senior author Susan DeSanto-Madeya, PhD, RN, FAAN, a Beth Israel Hospital Nurses Alumna Association endowed nurse scientist. “Many of these rooms were originally designed for patient privacy and quiet, but a key safety element in critical care is patient visibility, so we modified the spaces to accommodate ICU workflow.”

Modifications included putting windows in all patient room doors, and repositioning beds and monitors so patients and screens could be easily seen without entering the room. Lines of visibility were augmented with mirrors and baby monitor systems as necessary. Care providers were given two-way radios to decrease the number of staff required to enter a room when hands-on patient care was necessary. Mobile supply carts and workstations helped streamline workflow efficiency.

Besides stockpiling and managing medical equipment including PPE, ventilators and oxygen, increasing ICU capacity also required redeploying 150 staff trained in critical care. The hospital developed a recall list for former ICU nurses, as well as medical-surgical nurses that could care for critically ill patients on teams with veteran ICU nurses.

Education and support was provided from . In-person, socially-distanced workshops were developed for each group, after which nurses were assigned to shadow an ICU nurse to reduce anxiety, practice new skills and gain confidence.

“Staff identified the shadow experience as being most beneficial in preparing them for deployment during the COVID surge,” said O’Donoghue. “Historically, BIDMC has had strong collaborative relationships with staff from different areas and these relationships proved to be vital to the success of all the care teams. The social work department played a major role in fostering teams, especially during difficult situations.”

One of the redeployment teams was the ICU proning team. Proning is known to improve oxygenation in patients with acute respiratory distress syndrome is a complex intervention, takes time and is not without its potential dangers to the patient and staff alike. The coalition maximised resources and facilitated more than 160 interventions between March and May of 2020.

“Although the pandemic was an unprecedented occurrence, it has prepared us for potential future crises requiring the collaboration of multidisciplinary teams to ensure optimal outcomes in an overextended environment,” O’Donoghue said. “BIDMC’s staff rose to the challenge, and many positive lessons were learned from this difficult experience.”

“We must continue to be vigilant in our assessment of what worked and what did not work and look for ways to improve health care delivery in all our systems,” said DeSanto-Madeya, who is also an associate professor at the College of Nursing at the University of Rhode Island. “The memories from this past year and a half cannot be forgotten, and we can move forward confidently knowing we provided the best care possible despite all the hardships.”

Source: Beth Israel Deaconess Medical Center

Categories : COVIDTags :

Pharma Giants Draw Their Plans Against Omicron

On By ModernMedia
Image by Ivan Diaz on Unsplash

As world leaders seek to reassure an anxious world about the emergence of Omicron, Moderna’s CEO believes that vaccines will not have the same level of effectiveness against the new variant. Meanwhile, other major vaccine developers such as Oxford University maintain that it is still too early as yet to draw conclusions, and existing vaccines can be updated in a matter of months.

In an interview with the Financial Times, Moderna CEO Stéphane Bancel said that “in no world” would vaccines protect against Omicron at the same level as they did against Delta. He added that he thought it would be “material drop”, though data was still to come. However, the scientists he spoke to had all said “‘This is not going to be good’.” This is because 32 of the variant’s 50 mutations are on the Spike protein, which current vaccines are designed to target.

He noted the reduced effectiveness of existing vaccines against Delta, saying that scientists had not expected such a high level of mutation to emerge for another two to three years. His comments come in stark contrast to others who stress that there is no information yet to suggest that Omicron is any more serious than previous variants, or that vaccines are less effective against it.

Oxford University released a statement saying they were monitoring the situation, but stood ready to produce a new vaccine if necessary.

“Despite the appearance of new variants over the past year, vaccines have continued to provide very high levels of protection against severe disease and there is no evidence so far that Omicron is any different.

“However, we have the necessary tools and processes in place for rapid development of an updated COVID vaccine if it should be necessary.”

Pfizer’s CEO Albert Bourla said in an interview with CNBC that his company had already started work on an updated vaccine, which would be ready in 100 days.

In the Netherlands, scientists from the country’s National Institute of Public Health said that they had detected Omicron on flights that had arrived from Southern Africa before the official announcement of the discovery by South Africa. The country is now trying to locate and isolate some 5000 individuals who arrived in the country from the region. 

Categories : COVID PaediatricsTags :

Kids’ Spit Could be a Great COVID Test

On By ModernMedia
Photo by CDC

Saliva samples are easy to obtain and useful for measuring antibodies to SARS-CoV-2 in children, which could improve epidemiological surveillance in school settings. The study followed over 1500 children who went to summer schools in Barcelona last year. The results were published in BMC Medicine.

One of the pressing questions during this pandemic has been to understand children’s susceptibility to SARS-CoV-2 infection and how they infect others. An obstacle to answer this question is that most infections in children are mild or asymptomatic, and are therefore missed. To establish whether an individual has been exposed to SARS-CoV-2 in the past, virus-specific antibodies in blood need to be detected. Measuring antibody prevalence over time in a cohort of children can provide very valuable epidemiological information. However, this requires techniques that are both sensitive and minimally invasive.

In this study, performed through the Kids Corona platform, the team led by Carlota Dobaño, from the Barcelona Institute for Global Health (ISGlobal), and Iolanda Jordan, from Hospital Sant Joan de Déu (HSJD), used saliva instead of blood to measure virus-specific antibodies in over 1500 children who attended different summer schools in Barcelona in 2020, as well as around 400 adult staff. Two saliva samples per participant were analysed, one at the beginning and one at the end of the camp stay, and different antibody types (IgG, IgA and IgM) targeting different viral antigens were measured.

The study found that 3.2% of the participants developed antibodies between the first and second sample, indicating new infections. This is six times higher than the infection rate estimated by weekly PCR screening. “It has been reported that some children can be positive for antibodies despite being negative by PCR, which suggests that they can generate an immune response that prevents the establishment of SARS-CoV-2 infection,” explained Dobaño, first author of the study. It could also be because asymptomatic children have lower viral loads or that their viral clearance is faster.

Furthermore, the analysis shows that the percentage of new infections was higher in adults (2.94%) than in children (1.3%), suggesting differences in infection and transmission dynamics. Finally, contrary to blood tests, asymptomatic people had higher levels of anti-Spike antibodies in saliva, suggesting these antibodies play a protective role in respiratory mucosae. “This means that anti-Spike antibodies in saliva could be used to measure protective immunity upon vaccination, especially in the case of intranasal vaccines,” said senior study co-author Gemma Moncunill.

“We previously demonstrated in other Kids Corona studies that saliva is useful for detecting virus by PCR. With this study, we demonstrate that it’s also an effective and much friendlier way to measure antibodies, making it the ideal sample for children, instead of the more invasive nasal swab,” said Jordan.

Source: EurekAlert!

Categories : COVID NeurologyTags :

About 1% of Hospitalised COVID Patients Develop Neurological Complications

On By ModernMedia
49-year-old female with past medical history of mitral valve disease and tricuspid valve regurgitation who developed headache followed by cough and fever presented to the ER with right upper eyelid ptosis (drooping). Credit: Radiological Society of North America and Scott H. Faro, M.D.

Approximately one in 100 patients hospitalised with COVID will likely develop complications of the central nervous system, according to a large international study. These can include stroke, haemorrhage, and other potentially fatal complications. The study was presented at the annual meeting of the Radiological Society of North America (RSNA).

“Much has been written about the overall pulmonary problems related to COVID, but we do not often talk about the other organs that can be affected,” said study lead author Scott H. Faro, MD, FASFNR, professor of radiology and neurology at Thomas Jefferson University. “Our study shows that central nervous system complications represent a significant cause of morbidity and mortality in this devastating pandemic.”

Dr Faro initiated the study after finding that only a small number of cases informed existing literature on central nervous system complications in hospitalised COVID patients.

To build a more complete picture, he and his colleagues analysed nearly 40 000 cases of hospitalised COVID patients, admitted between September 2019 and June 2020. Their average age was 66 years old, and two thirds were men.

Confusion and altered mental status were the most common causes of admission followed by fever. Comorbidities such as hypertension, cardiac disease and diabetes were common.

There were 442 acute neuroimaging findings most likely associated with the viral infection, with central nervous system complications in 1.2% of this large patient group.

“Of all the inpatients who had imaging such as MRI or a CT scan of the brain, the exam was positive approximately 10% of the time,” Dr Faro said. “The incidence of 1.2% means that a little more than one in 100 patients admitted to the hospital with COVID are going to have a brain problem of some sort.”

Ischaemic stroke, with an incidence of 6.2%, was the most common complication, followed by intracranial haemorrhage (3.72%) and encephalitis (0.47%).

A small percentage of unusual findings was uncovered, such as acute disseminating encephalomyelitis, an inflammation of the brain and spinal cord, and posterior reversible encephalopathy syndrome, a syndrome that mimics many of the symptoms of a stroke.

“It is important to know an accurate incidence of all the major central nervous system complications,” Dr Faro said. “There should probably be a low threshold to order brain imaging for patients with COVID.”

Source: EurekAlert!

Categories : COVIDTags :

WHO Criticises Omicron Travel Bans as SA Stays at Level 1

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Image by Quicknews

The emergence of the Omicron SARS-CoV-2 variant which has resulted in renewed lockdowns and travel bans around the world, which have been criticised by the WHO. In contrast, South Africa will stick to an adjusted Level 1 lockdown for the time being, though pushing for mandatory vaccinations. Business and civil society groups had warned that increasing restrictions would have provoked backlash as recent election campaign events had effectively ignored them.

Many nations around the world have reacted quickly to the new variant, which has a large number of mutations compared to the Delta variant. The UK’s decision to suspend flights from South Africa as well as nine other African countries has provoked criticism from a number of quarters, including President Cyril Ramaphosa. The sudden move has caught many travellers by surprise, including a Welsh rugby team which had two members test positive, one of which was for Omicron. They will have to self-isolate before they are able to return, depending on flight availability.

Japan and Israel have taken the more extreme steps of closing their borders to foreigners. The first cases of Omicron that were recorded in Botswana were revealed to be in visiting diplomats, although which country they came from has not been revealed. 

The World Health Organization criticised the imposition of travel restrictions, acknowledging that although they may play a role in slightly reducing the spread of COVID, they still place a heavy burden on lives and livelihoods. It pointed out that if restrictions are implemented, they should not be unnecessarily invasive or intrusive, and should be scientifically based, under international law, the International Health Regulations. It notes South Africa followed International Health Regulations, and informed WHO as soon as its national laboratory identified the Omicron variant. 

“The speed and transparency of the South African and Botswana governments in informing the world of the new variant is to be commended. WHO stands with African countries which had the courage to boldly share life-saving public health information, helping protect the world against the spread of COVID,” said Dr Matshidiso Moeti, WHO Regional Director for Africa. “On the eve of a special session on pandemic preparedness I urge all countries to respect their legal obligations and implement scientifically based public health actions. It is critical that countries which are open with their data are supported as this is the only way to ensure we receive important data in a timely manner.”

Although a full picture of the new variant’s severity is still two or three weeks away, Angelique Coetzee, chair of the South African Medical Association, told the AFP she had recently seen around 30 patients at her Pretoria practice who tested positive for COVID but had unfamiliar symptoms.

“What brought them to the surgery was this extreme tiredness,” she said, something she said was unusual for younger patients. Most were men under 40, and just under half were vaccinated. Other symptoms included mild muscle aches, a “scratchy throat” and dry cough, she said. Just a few had a slightly high temperature. These very mild symptoms stand in contrast to other variants, which typically result in more severe symptoms.

Categories : COVIDTags :

Viral RNA Levels Can Predict COVID Mortality

On By ModernMedia
Photo by Mufid Majnun on Unsplash

Viral RNA levels in the blood is a reliable indicator in predicting COVID mortality, according to a study published in Science Advances.

“In our study, we were able to determine which biomarkers are predictors of mortality in the 60 days following the onset of symptoms,” said Université de Montréal medical professor Dr. Daniel Kaufmann, the study’s co-lead author alongside colleagues Nicolas Chomont and Andrés Finzi.

“Thanks to our data, we have successfully developed and validated a statistical model based on one blood biomarker,” viral RNA, Prof Kaufmann said.

Despite advances in COVID management, identifying patients at greater risk of dying of the disease has been difficult. Other studies identified various biomarkers, but assessing so many parameters is not possible in a clinical setting and gets in the way of doctors’ quick clinical decision-making ability.

Using blood samples from 279 patients hospitalised for COVID of differing severity, Kaufmann’s team measured amounts of inflammatory proteins, looking for any that stood out.

At the same time, Chomont’s team measured the amounts of viral RNA and in Finzi’s the levels of antibodies targeting the virus. Samples were collected 11 days after the onset of symptoms and patients were monitored for a minimum of 60 days after that.

The goal: to test the hypothesis that immunological indicators were associated with increased mortality.

“Among all of the biomarkers we evaluated, we showed that the amount of viral RNA in the blood was directly associated with mortality and provided the best predictive response, once our model was adjusted for the age and sex of the patient,” said Elsa Brunet-Ratnasingham, a doctoral student in Kaufmann’s lab and co-first author of the study.

“We even found that including additional biomarkers did not improve predictive quality,” she added.

Prof Kaufmann and Brunet-Ratnasingham tested the model on two independent cohorts of infected patients from Montreal’s Jewish General Hospital (recruited during the first wave of the pandemic) and the CHUM (recruited during the second and third waves).

No matter which hospital the patients were treated at, nor which period of the pandemic they fell into: in all cases, the predictive model worked. Now Prof Kaufmann and his colleagues want to put it to practical use.

“It would be interesting to use the model to monitor patients,” he said, “with the following question in mind: when you administer new treatments that have proven effective, is viral load still a predictive marker of mortality?” 

Source: University of Montreal

Categories : COVIDTags :

A New Variant, B.1.1.529, Emerges in South Africa

On By ModernMedia
Image by Quicknews

The National Institute for Communicable Diseases (NICD), yesterday confirmed that a new COVID variant, B.1.1.529, has been detected in South Africa. Initially detected in Botswana, 22 cases of variant B.1.1.529 have been recorded in the country following genomic sequencing. More cases are being confirmed as sequencing results come out. 

Detected cases and positivity rates are increasing quickly, particularly in Gauteng, North West and Limpopo. The UK government has acted rapidly to temporarily suspend all inbound flights from South Africa and neighbouring countries, and impose quarantines for recent arrivals.

“It is not surprising that a new variant has been detected in South Africa,” commented Prof Adrian Puren, NICD Acting Executive Director, adding that, “Although the data are limited, our experts are working overtime with all the established surveillance systems to understand the new variant and what the potential implications could be. Developments are occurring at a rapid pace and the public has our assurance that we will keep them up to date.”

‘Warp speed’ effort to track and understand variant
Dr Michelle Groome, Head of the Division of Public Health Surveillance and Response at the NICD said that provincial health authorities remain on high alert and are prioritising the sequencing of COVID positive samples.  A top priority is to track the variant more closely as it spreads: it was first identified in Botswana this month and has turned up in travellers to Hong Kong from South Africa. Scientists are also trying to determine the variant’s properties such as vaccine evasion and disease severity.

“We’re flying at warp speed,” said Penny Moore, Wits University virologist, whose lab is gauging the variant’s immunity evasion ability. While there are anecdotal reports of reinfections and cases in vaccinated individuals, “at this stage it’s too early to tell anything,” Moore cautioned.

“There’s a lot we don’t understand about this variant,” Richard Lessells, an infectious disease physician at the University of KwaZulu-Natal, said at a press briefing organised by South Africa’s health department on 25 November. “The mutation profile gives us concern, but now we need to do the work to understand the significance of this variant and what it means for the response to the pandemic.”

The variant’s apparent sharp rise in Gauteng is cause for alarm. Cases increased rapidly in the province in November, particularly in schools and among young people, according to Lessells. Genome sequencing and other genetic analysis found that the B.1.1.529 variant was responsible for all of 77 of the virus samples they analysed from Gauteng, collected between 12 and 20 November. Analysis of hundreds more samples are in the works. A previous variant, C.1.2, appeared in South Africa and had concerning mutations, but ultimately failed to replace Delta over the winter.

Fortunately, the variant has a spike mutation easily detected by fast genotyping tests as opposed to genome sequencing, according to Lessells. Preliminary data from these tests suggest that B.1.1.529 is spreading much wider than Gauteng. “It gives us concern that this variant may already be circulating quite widely in the country,” Lessells said.

Are vaccines effective against it?
As happened with the Beta variant, a similar effort is starting to study B.1.1.529. Moore’s team, which provided some of the initial data on Beta’s immunity-dodging, has begun work on B.1.1.529. They plan to test the virus’s ability to evade infection-blocking antibodies, as well as other immune responses. The variant harbours a high number of mutations in regions of the spike protein that antibodies recognise, potentially dampening their potency.

“Many mutations we know are problematic, but many more look like they are likely contributing to further evasion,” said Moore. There are even hints from computer modelling that B.1.1.529 could evade immunity conferred by T cells, Moore added. Her team hopes to have its first results in two weeks.

“A burning question is does it reduce vaccine effectiveness, because it has so many changes,” said Aris Katzourakis, who studies virus evolution at the University of Oxford, UK.

Researchers in South Africa will also study the disease severity of B.1.1.529, Lessells said, which is “the really key question”.

Sources: NICD, Nature

Categories : COVIDTags :

South Africa Faces Vaccine Glut as Uptake Slows

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Photo by Mat Napo on Unsplash

South Africa has asked Johnson & Johnson and Pfizer to delay delivery of COVID vaccines as it has too much stock now, health ministry officials said, as vaccine hesitancy continues to slow the immunisation campaign.

About 35% of South Africans are fully vaccinated, still only half the government’s target of 70% by year end. In the past 15 days, an average of 106 000 doses a day have been administered. At the beginning of the year, the programme had been beset by a lack of doses for a wide range of reasons, from AstraZeneca’s ineffectiveness against the Beta variant to overseas production delays. 

Deputy director-general of the Health Department, Nicholas Crisp, told Reuters that South Africa had 16.8 million doses in stock and said that deliveries had been deferred.

A spokesman for the Health Ministry said: “We have 158 days’ stock in the country at current use. We have deferred some deliveries.”

Stavros Nicolaou, chief executive of Aspen Pharmacare, which is packaging 25 million doses a month of J&J vaccines in South Africa, said most of the vaccines bound for South Africa would now be diverted to the rest of Africa, and deliveries would likely be deferred until the first quarter of next year.

A Pfizer spokesperson said: “We remain adaptable to individual country’s vaccine requirements whilst continuing to meet our quarterly commitments as per the South Africa supply agreement.”

The government has been trying to boost the rate of daily administered doses, such as with R100 ‘Vooma vouchers’ for registering to vaccinate, but even these have failed to sufficiently stoke uptake.

“There is a fair amount of apathy and hesitancy,” said Wits University’s Professor Shabir Madhi.

On Twitter, he further suggested using the excess stock for booster shots, which would “provide all single dose JJ adult recipients a JJ or Pfizer boost, and  those > 65 or immunosuppressive conditions an additional Pfizer dose if received 2 doses > 5 months ago.” 

Source: U.S. News