Category: COVID

Keeping an Eye on B.1.621’s Immune Escape Potential

Source: Viktor Forgacs on Unsplash

First detected in Colombia in January, the SARS-CoV-2 variant B.1.621 was recently named a ‘variant of interest’ by the European Centre for Disease Prevention and Control, reports MedPage Today. So far, neither the World Health Organization nor the CDC has elevated it to this status and it hasn’t received a greek letter designation yet.

B.1.621 has been detected in the US, though it (along with version B.1.621.1) currently accounts for just about 1% of all cases in the country. In the state of Florida, though, recent data from the University of Miami showed that 9% of cases in the Jackson Memorial Health System were B.1.621 as of the second week of July.

Last week, seven residents in a Belgian nursing home died after being infected with B.1.621, despite the fact that all of them had been vaccinated (though which vaccine was not disclosed. All of the deceased were in their 80s or 90s, and some were in poor health already, according to virologist Marc Van Ranst, who conducted tests on the virus found in the nursing home, Reuters reported. A total of 21 residents had been infected with the variant, along with several staff members. However, infected staff only had mild symptoms. B.1.621 makes up less than 1% of known cases in Belgium overall, according to Reuters.

Public Health England said that as of 2 August, there have been 32 cases (PDF) of the variant in England, with the majority (19%) being detected in London. This new variant has E484K and K417N mutations, making it similar to the Beta variant (B.1.351), prompting concern that B.1.621 could have similar immune escape properties, the agency noted.

In a recent risk assessment (PDF), Public Health England said that there is lab evidence of a reduction in pseudovirus neutralisation in the serum of vaccinated or previously Delta-infected individuals.
However, the agency noted that the trajectory of this new variant depends on its growth and expansion, and currently there’s no sign that it’s outcompeting Delta and it also seems unlikely that it’s more contagious. Still, its immune escape properties could contribute to future changes in growth, they warned, and other epidemiological events could influence whether it becomes established in the UK.

A recent paper in Lancet Infectious Diseases found two cases of B.1.621 involving community transmission, at a time when 99% of cases were due to the Delta variant. Both of these cases however occurred among unvaccinated individuals.

However, the dominance of Delta seems to be keeping other variants at bay, at least for now.

Source: MedPage Today

SA’s Department of Tourism Aims to Join Vaccine Passport System

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The Department of Tourism says that it wants to introduce a vaccine passport for South Africa, but a number of international and legislative obstacles have to be overcome.

A lack of standardisation around vaccine passports worldwide is a key issue, said tourism director-general Nkhumeleni Victor Tharage in a briefing to Parliament on 17 August.

“Even in some jurisdictions that have opted to apply this (passport), there isn’t yet a sense of uniformity. When we don’t have a single, standardised specimen, it is a little bit difficult to say which one is which.

“If South Africa introduces (a passport), and there is access to information from the National Institute for Communicable Diseases (NICD) that confirms that a person has been vaccinated, the question is if that person arrives Lagos (Nigeria), what resources will they use to verify this information that is stored on a database in South Africa?”

South Africa has the same problem when it comes to verification of incoming tourists, Tharage said. The government was also cautious about introducing a vaccine passport system that is discriminatory against certain groups of people, he noted.

“When we reopen, and when everyone is starting to travel, it should not be discriminatory. And that principle has been reiterated time and time again.”

The vaccine passport could be a requirement for events, and Tharage said he was confident that this is something that the government could introduce with ease on short notice.

“At the end of the day, it’s about being able to get the necessary confidence from consumers, tourists and trade. If we don’t do that, then there will be a negative impact on our recovery.”

However, Department of Health spokesperson Foster Mohale affirmed that South Africa has no immediate plans to require proof of vaccination for any purpose.

Open for tourism
Transport minister Fikile Mbalula has said that his department is working with businesses to ensure that South Africa successfully reopens for international travel. Presenting his departmental budget speech at the end of May, Mbalula said that South Africa must ensure that it joins the increasing number of countries which accept the International Air Transport Association’s (IATA) mobile travel pass.

The travel pass is a mobile app that helps travellers store and manage their verified certifications for COVID tests or vaccines, and is more secure and efficient than current paper processes, IATA said. This is important given the potentially enormous scale of testing or vaccine verifications that the group must securely manage. IATA said it is looking to introduce further changes, such as QR code scanning by immigration officials.

Source: BusinessTech

One in Ten COVID Cases Infected After Hospital Admission

Photo by Gustavo Fring from Pexels

In the UK’s first wave, more than one in ten COVID hospitalised patients acquired the disease in a hospital according to researchers conducting the world’s largest study of severe COVID.

Dr Jonathan Read from Lancaster University with colleagues from other UK universities led the research into hospital-acquired infections (HAIs) which was published in The Lancet.

For the study, researchers analysed records of COVID patients in UK hospitals enrolled in the International Severe Acute Respiratory and Emerging Infections Consortium (ISARIC) Clinical Characterisation Protocol UK (CCP-UK) study, who became ill before 1st August 2020.

The researchers found that at least 11.1% of COVID patients in 314 UK hospitals were infected after admission. The proportion of hospital-acquired infections also rose to between 16% and 20% in mid-May 2020, well after the first wave’s peak in admissions.

“We estimate between 5699 and 11 862 patients admitted in the first wave were infected during their stay in hospital. This is, unfortunately, likely to be an underestimate, as we did not include patients who may have been infected but discharged before they could be diagnosed,” the researchers said.

“Controlling viruses like SARS-CoV-2 has been difficult in the past, so the situation could have been much worse. However, infection control should remain a priority in hospitals and care facilities,” said Dr Read.

Dr Chris Green, University of Birmingham, said: “There are likely to be a number of reasons why many patients were infected in these care settings. These include the large numbers of patients admitted to hospitals with limited facilities for case isolation, limited access to rapid and reliable diagnostic testing in the early stages of the outbreak, the challenges around access to and best use of PPE, our understanding of when patients are most infectious in their illness, some misclassification of cases due to presentation with atypical symptoms, and an under-appreciation of the role of airborne transmission.”

According to the type of care provided, there were notable differences in infections. Lower proportions of hospital-acquired infection were seen in hospitals providing acute and general care (9.7%) than residential community care hospitals (61.9%) and mental health hospitals (67.5%).
Professor Calum Semple, University of Liverpool, said: “The reasons for the variation between settings that provide the same type of care requires urgent investigation to identify and promote best infection control practice. Research has now been commissioned to find out what was done well and what lessons need to be learned to improve patient safety.”

Source: Lancaster University

Molnupiravir Works by Inducing Mutations in SARS-CoV-2

Researchers have shown that the antiviral drug molnupiravir, currently in clinical trials as a COVID treatment, works by inducing mutations in SARS-CoV-2 which prevent the coronavirus from replicating further.

Since the onset of the corona pandemic, researchers have been developing various vaccines and drugs to varying degrees of success. Previous studies have shown why the antiviral drug remdesivir, the first one approved against COVID, has a rather weak effect on the virus. “Remdesivir does interfere with the [viral] polymerase while doing its work, but only after some delay. And the drug does not fully stop the enzyme,” said Max Planck Director Patrick Cramer. 

Molnupiravir was originally developed to treat influenza and in preliminary clinical trials, the compound is promising against SARS-CoV-2. “Knowing that a new drug is working is important and good. However, it is equally important to understand how molnupiravir works at the molecular level in order to gain insights for further antiviral development,” explained Cramer. “According to our results, Molnupiravir acts in two phases.”

Induced RNA mutations halt replication
Molnupiravir, an orally available drug, becomes activated through metabolisation in the body. When it enters the cell, it is converted into RNA-like building blocks. In the first phase, viral RNA polymerase incorporates the building blocks into the virus’ own RNA. However, unlike remdesivir, which merely slows the viral RNA polymerase, molnupiravir does not interfere with its copying functions. Instead, in the second phase, the RNA-like building blocks connect with the building blocks of the viral genetic material. “When the viral RNA then gets replicated to produce new viruses, it contains numerous errors, so-called mutations. As a result, the pathogen can no longer reproduce,” explained Florian Kabinger, a doctoral student in Cramer’s department.
Molnupiravir also appears to do this for other viruses “The compound could potentially be used to treat a whole spectrum of viral diseases,” said Höbartner, a professor of chemistry at the University of Würzburg. “Molnupiravir has a lot of potential.” 
Currently, molnupiravir is in phase III studies, where it is being tested on a large number of patients and is being evaluated for safety. The US government has already secured 1.7 million doses, at a cost of US$1 billion. However, working out at a cost of nearly US$600 per dose, it will not be cheap.

The researchers published their findings in Nature Structural & Molecular Biology.

Source: Max Planck Institute

WHO Urges Support for New COVID Origin Investigation

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The World Health Organization (WHO) has urged all countries “to put differences aside” in order to speed up investigations into the origins of the SARS-CoV-2 virus – including the unproven suggestion that it was accidentally released from laboratory.

This announcement follows a joint report into the origins of the coronavirus issued in March by the WHO and China. The UN agency, noting “insufficient scientific evidence to rule any of the hypotheses out” about the origins of the new coronavirus, insisted that to address the ‘lab hypothesis’, it needed access “to all data” in order to prevent global health threats in future.
“WHO calls for all governments to depoliticise the situation and cooperate to accelerate the origins studies, and importantly to work together to develop a common framework for future emerging pathogens of pandemic potential,” it said.

“We call on all governments to put differences aside and work together to provide all data and access required so that the next series of studies can be commenced as soon as possible.”

In a detailed statement, WHO explained the need for additional studies into “all hypotheses” about how SARS-CoV-2 made the jump from animals to humans.

Transparency call
A new independent advisory group of experts, the International Scientific Advisory Group for Origins of Novel Pathogens (SAGO), will support the project by coordinating the studies recommended in the March report, it said.

Nominations for the panel would be welcomed from all countries, WHO said, whose task would be similar to previous COVID missions to China and those launched to investigate the origins of avian influenza, Lassa virus and Ebola virus.

“This open call aims to ensure that a broad range of scientific skills and expertise are identified to advise WHO on the studies needed to identify the origins of any future emerging or re-emerging pathogen of pandemic potential,” the UN agency said.

Scientific endeavour
Noting how hard it is to identify the origin of any novel pathogen, the agency insisted that the mission “is not and should not be an exercise in attributing blame, finger-pointing or political point-scoring. It is vitally important to know how the COVID pandemic began, to set an example for establishing the origins of all future animal-human spill-over events.”

Access to sensitive information was needed for the success of the operation with “a further examination of the raw data from the earliest cases”, along with blood serum from potentially infected people in 2019, before the pandemic.

Data sharing
Data from “a number of countries” that reported finding the virus in blood samples taken in 2019 has already been shared with WHO, it noted. This included Italy, where WHO coordinated retesting of pre-pandemic blood samples outside the country.

“Sharing raw data and giving permission for the retesting of samples in labs outside of Italy reflects scientific solidarity at its best and is no different from what we encourage all countries, including China, to support so that we can advance the studies of the origins quickly and effectively,” WHO said, and restated that access to data was “critically important for evolving our understanding of science and should not be politicised in any way”.

Source: UN News

Western Cape Plateaus but Still in Grip of Third Wave

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In a digital media briefing, Western Cape Premiere Alan Winde said that the province had still not exited its third wave of COVID infections.

With an R value of 0.9, this was the first time in the third wave that the value was below 1. However, this could be due to testing delays caused by the long weekend. Indeed, a sharp daily increase in national COVID cases has been recorded as of Thursday’s latest data, with the NICD reporting a 90% jump to 14 271. Overall case positivity still hovers above the 20% mark at 22.52%.

Cases continue to spike
While overall cases in the Western Cape are plateauing, spikes in certain areas are seeing higher case rates than in the peak of the second wave. Oxygen is still being used as fast as it can be produced in the province, being supplemented by an additional 22 tonnes per day by truck deliveries from other provinces. A total of 3665 patients are in acute hospitals, with 99% occupancy in Metro areas. The Metro area is seeing a week-on-week case rise of 7%, which points to a plateau.

Vaccines proving effective – even against beta
The Johnson & Johnson vaccine however is proving effective, with 91-95% protection against death and 65-66% protection against hospitalisation. With regard to variants, the vaccine confers 67% protection against hospitalisation when beta is dominant and 71% where delta is dominant.

The Western Cape’s vaccination programme remains on track, with 287 000 doses of Pfizer and 28 800 J&J doses to arrive today, Friday 13th. 

Elsewhere, with 31.2 new cases per 100 000 people, KwaZulu-Natal may be becoming a COVID hotspot. 

A further 473 people have died from COVID, bringing the official death toll to 76 247.

Source: Western Cape Government

New Study Sheds More Light on AstraZeneca Blood Clots

Credit: National Institutes of Health

A UK study has furthered the understanding of the novel blood-clotting condition associated with the Oxford/AstraZeneca vaccine.

Vaccine-induced immune thrombocytopenia and thrombosis (VITT) is characterised by a blockage of veins and a marked platelet reduction. The rare condition was first identified in the UK by Professor Marie Scully (University College of London Institute of Cardiovascular Science), also a Consultant Haematologist at UCLH, and Dr Will Lester from University Hospitals Birmingham NHS Foundation Trust.

In a paper published in the New England Journal of Medicine (NEJM), the first 220 cases of definite and probable VITT in the UK are detailed.

The cases were presented by 182 consultant haematologists, and builds on understanding about the condition outlined in an April 2021 NEJM paper led by Professor Scully.

Meanwhile, a study led by Dr Richard Perry (UCL Queen Square Institute of Neurology and UCLH) published in the Lancet earlier this month provided the most detailed observations so far of cases of cerebral venous thrombosis (CVT). one of the commonest and severest manifestations of VITT.

The overall mortality rate of those presenting to hospitals with definite or probable VITT was 23%, the paper reported. The condition almost entirely manifested between five and 30 days after their first vaccination, with no sex differences seen, and no predisposing prior medical conditions.

The chances of death increased significantly the lower the platelet count and the greater the activation of the blood clotting system, increasing to 73% in patients with a very low platelet count and intracranial haemorrhage following blood clots in the brain.

Overall, 41% of patients had no previous medical diagnoses and 85% were less than 60 years old. Overall incidence in individuals under 50 was estimated to be 1 in 50 000 – in line with reports from other countries.

Though optimal treatment was still uncertain, it was being continually refined in real time, the researchers wrote. For instance, the introduction of the use of plasma exchange in the most severe cases has led to survival rates that were significantly better than would be predicted based on baseline characteristics.

The research adds to evidence for use of non-heparin-based blood thinners to tackle blood clotting in cases of VITT, and that use of intravenous immunoglobin was associated with better outcomes.

Professor Scully said: “As a new condition we are still learning about how best to diagnose and manage VITT, but as time goes on, we have been able to refine our treatment approaches and improve rates of survival and chance of recovery. This continuous learning in real time has been made possible thanks to collaboration between colleagues across the UK.”

Lead author Dr Sue Pavord, at Oxford University Hospitals NHS Foundation Trust, said: “We have worked relentlessly to understand and manage this new condition, so that the hugely successful vaccine roll out can continue, which is the most viable solution to the global pandemic.”

Source: University College London

Are There Different Symptoms for the Delta Variant?

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MedPage Today investigates whether, according to some reports, there is in fact a difference in Delta symptoms compared to earlier variants.

Though hard data are lacking, ZOE study leader Tim Spector, MB, MSc, MD, of King’s College London, said his app’s data suggests the disease is “acting different now. It’s more like a bad cold in this younger population.”

Headache, followed by sore throat, runny nose, and fever were now the most common reported symptoms.

“All those are not the old classic symptoms,” Dr Spector said, adding that cough dropped to fifth place, and “we don’t even see loss of smell coming into the top 10 anymore. This variant seems to be working slightly differently.”

Dr Spector’s data however is only preliminary and comes from self-reports, and has not even been peer reviewed or published. However, other experts also have noticed a change in reported COVID symptoms.

One of those who has heard reports but is cautious about their interpretation is David Kimberlin, MD, a paediatric infectious diseases expert at the University of Alabama at Birmingham.

“I don’t think with what we know right now that we can conclude [Delta] is much different in terms of symptoms,” Dr Kimberlin told MedPage Today. “There have been some reports that it causes more cold-like illness, but so did the original COVID. I think we’ll know more over the next couple of months as we have the opportunity to realise the data.”

Purvi Parikh, MD, of NYU Langone in New York City and a spokesperson for the American College of Allergy, Asthma & Immunology, has also heard of COVID being mistaken for allergies, but allergies do not come with high fever, nausea, vomiting, or diarrhoea.

Other symptoms unlikely in allergy include myalgia and chills, said Alan Goldsobel, MD, of Allergy & Asthma Associates of Northern California, who is also a professor at Stanford University. Allergy indicators include the time of year (for those with seasonal allergy), as well as itching, he added.

Distinguishing COVID from common cold symptoms could be harder, Drs Parikh and Goldsobel noted.

“If you aren’t sure, I do recommend COVID testing,” Dr Parikh said.

Source: MedPage Today

Attaining Herd Immunity for COVID Now Unlikely

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In an article published in the South African Medical Journal, Shabir Madhi, Professor of Vaccinology at Wits, argues that COVID variants have made the initial goal of attaining herd immunity no longer feasible, even for well-resourced countries. However, vaccine protection against severe COVID seems a more realistic path to normalcy.

In low and middle income countries (LMICs), the official COVID case estimates are likely grossly underestimated, Prof Madhi writes, due to a lack of testing coverage. Even in South Africa, the true number of COVID cases is likely in the region of 10 times the 2.39 million recorded through testing. The true number of COVID-related deaths in India is also estimated as 3.4–3.9 million, again 10 times the official count, and in South Africa it is likely three times the official  figure of 70 388 in July 2021.

While New Zealand researchers have suggested that COVID eradication is feasible, it is likely a very long term goal if at all attainable. The herd immunity goal can be considered with the equation (p1 = 1 – 1/R0), where p1 is the proportion of immune individuals who will also no longer transmit the virus, and R0 is the reproduction rate, ie the number of susceptible individuals a single infected person can further infect. However, this ignores key aspects of the virus.

The problem is that the proportion of people that would need to be immunised to achieve herd immunity was initially calculated at 67%, based on an assumed R0 of 3, derived from the Wuhan strain’s R0 of 2.5 to 4. However, the Delta variant has an R0 of 6, meaning that to reach herd immunity, 84% of the population would need to be vaccinated. In South Africa, this would be 100% of the population aged over 12.

The emergence of SARS-CoV-2 variants, especially the Beta variant with the E484K mutation, showed that existing vaccine protection, including the Pfizer variant, can be degraded to an extent.

Studies have strongly suggested that neutralising and antibody titers are associated with mild to moderate COVID protection, while protection from severe COVID may be mediated by T-cell immunity.

Real world data showed that in Israel, with a world best immunisation of 61.6% using the Pfizer vaccine which produces the greatest antibody response, herd immunity appeared to be successful until an outbreak of the more transmissible Delta variant combined with waning vaccine effectiveness. 

However, in the UK, excess death data showed that, even with a resurgence of cases caused by the Delta variant, there was a significant decoupling of deaths from cases. This points to the effectiveness of vaccines in preventing severe illness, as opposed to reaching herd immunity.

Vaccine rollouts have therefore not interrupted COVID transmission. Prof Madhi concludes that, based on an estimated R0 of 6 for the Delta variant, “it is unlikely that any country could have a sustainable strategy for durable high level of protection against infection by the delta variant. Mutations of the SARS-CoV-2 genome are likely to continue resulting in enhanced transmissibility, infectiousness and resistance to neutralising activity.”

He observes that the “UK approach seemingly concedes that the goal of herd immunity, even in a highly resourced setting, is unattainable.”

He adds that aspiring to reach herd immunity by wealthy countries comes at the cost of exacerbating vaccine inequality, which he says “is immoral.”
Antibody dynamics modelling suggests that a booster would be required every 2–3 years to protect against severe COVID, and every 6–9 months to protect against moderate disease. This is a challenging goal, and likely unattainable for most LMICs, especially given the slow rate of vaccination in those settings.

Source: South African Medical Journal

COVID Eradication is Tough but not Impossible, Study Shows

Image by Ivan Diaz on Unsplash
Image by Ivan Diaz on Unsplash

A new analysis shows that the global eradication of COVID is tough but theoretically more feasible than for polio and less so than it was for smallpox.

The article in BMJ Global Health ranked the feasibility of eradicating the three diseases based on technical, socio-political and economic factors.

Smallpox, which was declared eradicated in 1980, had the highest average score for eradication feasibility. It had an average score of 2.7 on a three-point scale across 17 variables.  COVID had an average score of 1.6 which was close to polio’s average score of 1.5.

Professor Nick Wilson from the University of Otago said that their analysis shows COVID’s eradication is feasible.

Vaccination programmes, public health measures and the global interest in combating the disease together contribute to making eradication possible.

“Elimination of COVID-19 at the country level has been achieved and sustained for long periods in various parts of the Asia Pacific region, which suggests that global eradication is possible.”

Vaccination programmes eradicated smallpox and two of the three serotypes of poliovirus, while other diseases are close to eradication. China recently became the 40th country to be certified malaria-free.

In ranking the feasibility of eradication for the three diseases, the researchers incorporated factors including the availability of safe and effective vaccines, the possibility of lifelong immunity, the impact of public health measures, effective infection control messaging by governments, political and public concern about the infection and public acceptance of infection control measures.

While there has been a focus on the need to reach herd immunity to overcome COVID, population immunity may not be essential to combat the disease, as smallpox was eradicated through ring-vaccination programmes which target the contacts of those infected.

The challenges of eradicating COVID relative to smallpox and polio include poor vaccine acceptance in some countries and the emergence of variants of the pandemic virus that may be more transmissible or able to evade the protection from vaccines.

But Professor Wilson said eventually the virus will be reach the limit of more infectious mutations, and so new vaccines will likely be formulated to deal with evolving strains of the disease.

Other obstacles includedthe cost of global vaccination and upgrading health systems, and achieving international cooperation in the face of aggressive anti-science movements and vaccine nationalism.

Professor Wilson says while the virus may infect animal populations, they will note likely hamper eradication.

“Wild animal infections with SARS-CoV-2 appear to be fairly rare to date and when companion animals become infected, they don’t appear to reinfect humans.”

A co-author of the article, Professor Michael Baker from the University’s Department of Public Health, says global concern about the pandemic could be tapped.

“The massive scale of the health, social and economic impacts of COVID-19 in most of the world has generated unprecedented global interest in disease control and massive investment in vaccination programmes.

“Unlike smallpox and polio, control of COVID-19 also benefits from the added impact of public health measures, such as border controls, social distancing, contact tracing and mask wearing, which can be very effective if well deployed.”

Professor Baker says upgrading health systems to target COVID-19 could also help to control other diseases, and could even aid in eradicating measles.

“When all factors are taken into account, it could be that the benefits of eradicating COVID-19 outweigh the costs, even if eradication takes many years and has a significant risk of failure.”

This work is preliminary, the researchers cautioned.

“The World Health Organization or a coalition of national agencies working collaboratively needs to formally review the feasibility and desirability of attempting COVID-19 eradication on a global basis,” Professor Baker says.

The researchers noted it is important to distinguish between eradication of infection, ie the permanent reduction to zero of the worldwide incidence of infection caused by a specific agent as a result of deliberate efforts; and elimination, ie the reduction to zero of the incidence of infection caused by a specific agent in a defined geographical area as a result of deliberate efforts.

COVID elimination has been reached and sustained for long periods in a number of jurisdictions in the Asia-Pacific region (notably China, Hong Kong, Taiwan, Australia and New Zealand), demonstrating that global eradication is technically possible.

Source: EurekAlert!