In response to the third wave driven by the delta variant, President Cyril Ramaphosa instituted a two-week Level 4 lockdown during a ‘family meeting’ address to the nation.
He warned that the healthcare system was facing a dire situation. “Our health facilities are stretched to the limit… ICU beds are in short supply,” he said.
In a press briefing on Friday, the head of the World Health Organization said the COVID Delta variant, first seen in India, is “the most transmissible of the variants identified so far,” and warned it is now spreading in at least 85 countries.
“We are in the exponential phase of the pandemic with the numbers just growing very, very, extremely fast and (they) will keep growing in the next weeks,” said Tulio de Oliveira, a leading virologist in the country.
The Delta variant first seen in India now appears to be “dominating infections in South Africa,” de Oliveira of the Network for Genomic Surveillance in South Africa told a virtual briefing.
The Delta variant has emerged as dominant in South Africa. Source: Department of Science & Technology
Koleka Mlisana, the head of a government ministerial advisory committee on COVID, told the same briefing that there is “evidence that the Delta variant may actually be taking over”.
Acting Minister of Health, Mmamoloko Kubayi-Ngubane said that due to the prevalence of the Delta variant, infection numbers “are likely to surpass the second wave peak” in January.
Only about 2.4 million people have been immunised since February. Thousands of EFF activists rallied in Pretoria on Friday to demand a faster coronavirus vaccination rollout, including expedited approvals for the Sinovac vaccine from China and Russia’s Sputnik V.
Colorized scanning electron micrograph of an apoptotic cell (purple) heavily infected with SARS-COV-2 virus particles (yellow), isolated from a patient sample. Image captured at the NIAID Integrated Research Facility (IRF) in Fort Detrick, Maryland. Credit: NIAID
A preliminary study has possibly determined why the SARS-CoV-2 Delta variant is more infectious and pathogenic than its ancestor.
Through a series of in vitro experiments, researchers have discovered that variant’s enhanced ability to induce cell-to-cell fusion (syncytia) and reduced susceptibility to vaccine and infection-induced antibodies together help make the Delta variant more infectious than previously circulating variants. The study, which is yet to be peer reviewed, is currently available on the bioRxiv preprint server.
The SARS-CoV-2 virus has undergone more than 12 000 mutations since it was first detected in December 2019, most of which are neutral and do not contribute to viral evolution. However, the acquisition of specific mutations in structural and non-structural proteins has caused the emergence of novel, more virulent SARS-CoV-2 variants.
Spike protein mutations are particularly concerning as they can significantly influence viral infectivity, virulence, and immune evasion ability.
The B.1.617 lineage drove a massive surge in new COVID cases in India. This lineage is further divided into three sub-lineages, namely B.1.617.1, B.1.617.2, and B.1.617.3. Although these emerged first in India, the B.1.617.2 or Delta variant or soon became dominant in many countries, including South Africa where it has driven a new surge of infections, particularly in Gauteng Province. The World Health Organization (WHO) has designated the Delta variant as a ‘Variant of Concern’ (VOC) due to its significantly increased infectivity and pathogenicity.
In the current study, the scientists have evaluated the susceptibility of the Delta variant to neutralisation by vaccine or natural infection-induced antibodies.
Delta variant mutations
The Delta variant’s spike protein contains nine mutations in the S1 subunit and one mutation in the S2 subunit. In the S1 subunit, five mutations are present in the N-terminal domain containing binding sites (epitopes) for neutralising antibodies. In addition, two mutations are present in the receptor-binding domain of the S1 subunit, which is known to influence antibody-mediated neutralisation and infectivity. Among the three remaining mutations, two are known to increase angiotensin-converting enzyme 2 (ACE2) binding, viral replication, and spike protein cleavage at the S1/S2 site.
Delta variant host cell entry
Using African green monkey and human cells, the researchers found that Delta can enter kidney cells of both species with similar efficacy as the wild-type SARS-CoV-2. However, for human colon and lung cells, Delta showed 1.5-fold and 2-fold higher invading ability, respectively, compared to the wild-type virus. Since the Delta variant spike protein did not exhibit increased ACE2 binding, the scientists suggest that increased entry of B.1.617.2 into colon and lung cells is not mediated by enhanced ACE2 binding.
Besides inducing fusion between the viral envelope and host cell membrane, the spike protein triggers the fusion of infected cells with nearby cells to form large multinucleated cells, known as syncytia. Given the fact that spike-induced syncytia formation contributes to COVID pathogenesis, the scientists investigated whether Delta variant infection is associated with increased syncytia formation.
By conducting in vitro experiments on human lung cells expressing high levels of ACE2, they found that Delta spike expression leads to 2.5-fold higher and larger syncytia formation than the wild-type spike expression.
Delta variant’s immune evasion ability less than Beta?
The scientists tested the ability of four therapeutic monoclonal antibodies to neutralise the Delta variant, of which only Bamlanivimab failed. The other three antibodies exhibited similar efficacy in neutralising both wild-type virus and Delta variant.
Antibodies derived from COVID recovered patients, and BNT162b2-vaccinated individuals showed only slightly reduced efficacy in neutralising the Delta variant as compared to the wild-type virus. In contrast, the B.1.315 or Beta variant, first detected in South Africa, showed a significantly higher ability to evade infection- and vaccination-induced immunity.
In summary
The study showed that Delta’s increased ability to invade lung cells may enhance infectivity and pathogenicity. Though it has lower susceptibility to antibody-mediated neutralisation, it is possible that Delta may be effectively controlled by immunity developed in response to natural infection or vaccination.
Journal information: Arora P. 2021. Increased lung cell entry of B.1.617.2 and evasion of antibodies induced by infection and BNT162b2 vaccination. bioRxiv. https://www.biorxiv.org/content/10.1101/2021.06.23.449568v1
SARS-CoV-2 viruses emerging from a human cell. Credit: NIAID
Australian researchers studying SARS-CoV-2 have discovered that the virus is most ideally adapted to infect human cells — instead of bat or pangolin cells, prompting renewed questions about its origin.
The scientists, from Flinders University and La Trobe University, described how they used high-performance computer modelling of SARS-CoV-2’s structure at the beginning of the pandemic to predict its ability to infect humans and a range of 12 domestic and exotic animals.
They were hoping to identify an intermediate animal vector that may have played a role in transmitting a bat virus to humans, and to understand any risk posed by the susceptibilities of pets and livestock.
Using genomic data from 12 animal species, the researchers painstakingly built computer models of the key ACE2 protein receptors for each species. These models were then used to calculate how strongly the SARS-CoV-2 spike protein bound to each species’ ACE2 receptor.
Surprisingly, the results showed that SARS-CoV-2 bound to ACE2 on human cells more tightly than any of the tested animal species, including bats and pangolins. If one of the animal species tested was the origin, it would normally be expected to show the highest binding to the virus.
“Humans showed the strongest spike binding, consistent with the high susceptibility to the virus, but very surprising if an animal was the initial source of the infection in humans,” said Professor David Winkler at La Trobe University.
The findings, originally released on the ArXiv preprint server, have now been peer reviewed and published in Scientific Reports.
“The computer modelling found the virus’s ability to bind to the bat ACE2 protein was poor relative to its ability to bind human cells. This argues against the virus being transmitted directly from bats to humans. Hence, if the virus has a natural source, it could only have come to humans via an intermediary species which has yet to be found,” says Flinders affiliated Professor Nikolai Petrovsky.
The team’s computer modelling also showed fairly strong binding of SARS-CoV-2 to ACE2 from pangolins, which are occasionally used as food or in traditional medicines. Professor Winkler noted that pangolins displayed the highest spike binding energy of all the animals in the study – significantly higher than bats, monkeys and snakes.
“While it was incorrectly suggested early in the pandemic by some scientists that they had found SARS-CoV-2 in pangolins, this was due to a misunderstanding and this claim was rapidly retracted as the pangolin coronavirus they described had less than 90% genetic similarity to SARS-CoV-2 and hence could not be its ancestor,” Prof Petrovsky said.
Similarity in spike proteins
As shown in this and other studies, the specific part of the pangolin coronavirus spike protein that binds to ACE2 was almost identical to its SARS-CoV-2 counterpart.
“This sharing of the almost identical spike protein almost certainly explains why SARS-CoV-2 binds so well to pangolin ACE2. Pangolin and SARS-CoV-2 spike proteins may have evolved similarities through a process of convergent evolution, genetic recombination between viruses, or through genetic engineering, with no current way to distinguish between these possibilities,” Prof Petrovsky said.
“Overall, putting aside the intriguing pangolin ACE2 results, our study showed that the COVID-19 virus was very well adapted to infect humans.”
“We also deduced that some domesticated animals like cats, dogs and cows are likely to be susceptible to SARS-CoV-2 infection too,” Prof Winkler added.
The question of how the virus came to infect humans currently has two main explanations. The virus may have jumped to humans from bats through an intermediary animal which remains to be identified. The other explanation making headlines in the media is an accidental release from a virology lab, where it perhaps was created in ‘gain of function‘ tests, which are carried out around the world to better understand pathogens. A number of organisations and governments, including the World Health Organization and the United States have urged further investigation to find out which of these is correct — though a definitive answer may take years. How and where the SARS-CoV-2 virus adapted to become such an effective human pathogen remains a mystery, the researchers concluded, adding that finding the origins of the disease will help efforts to protect humanity against future coronavirus pandemics.
Journal information: Sakshi Piplani et al, In silico comparison of SARS-CoV-2 spike protein-ACE2 binding affinities across species and implications for virus origin, Scientific Reports (2021). DOI: 10.1038/s41598-021-92388-5
President Cyril Ramaphosa is expected to meet with the National Coronavirus Command Council (NCCC) to discuss the government’s response to the third COVID wave, which includes the possibility of new restrictions.
Several bodies have strongly urged upgrading to a harder lockdown, including the South African Medical Association, the Gauteng Provincial Government, medical professionals, and now the Ministerial Advisory Committee on Covid-19.
Earlier this week Ramaphosa indicated that the government will have to increase its COVID containmant measure – especially in Gauteng province. He noted that the country’s first hard lockdown in March 2020, one of the strictest in the world, did help cut infection rates at the start of the pandemic.
South Africa recorded 17 493 new cases, a new daily high for the third wave, of which 10 806 were in Gauteng. Case positivity rate increased to 24.92%. A report released on Wednesday by the South African Medical Research Council showed that 1349 excess deaths in Gauteng for the week ending 13 June, of which 431 were due to COVID/
Warnings and failure to act
In an interview with The Money Show with Bruce Whitfield this Monday, Netcare CEO Richard Friedland had warned that the numbers of Covid-19 patients “are overwhelming facilities at the moment”.
Since Wednesday last week, Gauteng’s hospitals had been battling with a “mass casualty situation” , not unlike the aftermath of a train accident, or the collapse of a sports stadium, with “injuries on a massive scale”. But, with COVID, he said, the crisis is not over in a couple of hours, but remains ongoing.
With no evidence of a peak in case numbers, Friedland said that, “I’m afraid that these numbers are demonstrating that [without] a Level 5 lockdown in Gauteng, we may not see the end of this surge for some time.”
Professor Koleka Mlisana, co-chairperson of the Ministerial Advisory Committee on Covid-19, says that tighter restrictions are likely needed to help curb infections.
Prof Mlisana said that the other major crisis is making sure that there are sufficient hospital beds in Gauteng. This includes additional facilities, staffing members and beds to ensure the system is not overwhelmed, she said.
Prof Mlisana said that this was down to a lack of preparation by the government, despite warnings from the advisory committees.
The WHO has urged that as air travel is restored, vaccinations should not be a prerequisite for travellers, potentially locking out those in poorer regions, especially Africa.
In a virtual press briefing on Thursday, Dr Matshidiso Moeti, World Health Organization Regional Director for Africa said that the WHO believes that schemes to remove quarantine and entry restrictions for travellers that have been vaccinated, are discriminatory and could deepen already existing inequalities even further.
Meanwhile, she warned that Africa’s third wave, already underway in 12 countries, with cases rising in another 14, threatens to be the worst yet with 5.3 million cases across the continent. It is projected that in three weeks the third wave will surpass the previous wave’s peak.
Public fatigue and new variants are driving this surge across Africa, with Delta the variant detected in 14 countries. She stated that Africa can “blunt this third wave” but “the window of opportunity is closing”.
The WHO aims to strengthen variant surveillance in Africa by reinforcing the regional laboratory hub have a 8 to 10 fold increase in next 6 months for genome sequencing
Though vaccination rates remain low in Africa, there is nevertheless a great demand for vaccines, with 18 countries having used over 80% of the vaccines received through COVAX. Fortunately only mild side effects from the vaccines have been seen in African communities, she said.
Mr Kamil Alawadi, Regional Vice President for Africa and Middle East, International Air Transport Association (IATA) said that inconsistent requirements added additional complications in travel, increasing cost for the passenger and the airline. For travellers, PCR testing can range from $100 up to $400 for a single, one direction trip.
The key requirement for the recovery of the airline industry is the lifting of restrictions, said Alwadi, citing a survey that showed that 84% of passengers will not fly if there were quarantines in place. However, demand still existed for air travel, as evidenced by travel bookings spiking as soon as governments relaxed their border restrictions.
Alawadi said that the IATA agreed with the WHO that only lifting quarantine requirements for vaccine individuals was inequitable, and that “a robust and flexible testing system” was needed in place of quarantine, using systematic testing at the point of departure such as rapid antigen tests which are cheaper, faster and more accessible.
Graphic from Skyscanner.net showing countries with major travel restrictions from South Africa (red, 83 countries), moderate (orange, 29) and low restrictions (green, 42)
The situation was urgent for the African aviation industry as it had lost USD7.8 billion in 2020, with eight airlines filing for bankruptcy, he noted. This was against a background of USD430 billion global loss for the industry, though he noted that some countries are seeing a rebound to 2019 numbers for domestic travel. However, it is projected that losses will only stop by 2023 and return to profit by 2024.
The IATA has developed protocols in concert with the International Civil Aviation Organization (ICAO) and WHO that will be non-discriminatory not require vaccinations, said Alwadi. However the aviation industry is sinking very rapidly without governmental support.
Researchers at Karolinska Institutet in Sweden have developed a technology for cost-effective surveillance of the global spread of new SARS-CoV-2 variants. This could help low- and middle-income countries monitor variants in their own borders.
From the beginning of the pandemic, thousands of viral genomes have been sequenced in order to reconstruct the evolution and global spread of the coronavirus. Dependent on these is the identification of particularly concerning variants.
To achieve global surveillance of the SARS-CoV-2 genome, the sequencing and analysis of numerous samples cost-effectively is key. Therefore, researchers in the Bienko-Crosetto laboratory at Karolinska Institutet and Science for Life Laboratory (SciLifeLab) in Sweden have developed a new method, COVseq, that can be used for surveillance of the viral genome on a massive scale at a low cost.
Multiplex PCR (polymerase chain reaction) is used to make more copies of the virus. The samples are then labeled and pooled together in the same sequencing library, using a previous method developed in their laboratory and now adapted for SARS-CoV-2 analysis.
“By performing reactions in very small volumes and pooling together hundreds of samples into the same sequencing library, we can sequence potentially thousands of viral genomes per week at a cost of less than 15 dollars per sample,” said co-first author Ning Zhang, postdoctoral researcher at the Department of Medical Biochemistry and Biophysics, Karolinska Institutet.
Comparative analyses of 29 SARS-CoV-2 positive samples revealed that COVseq could detect small changes in the genome as well as standard methods. Analysing 245 additional samples, they showed that COVseq could also detect emerging variants of concern well. COVseq’s key advantage over existing methods is cost-effectiveness.
“Our inexpensive method could immediately be used for SARS-CoV-2 genomic surveillance by public health agencies and could also be easily adapted to other RNA viruses, such as influenza and dengue viruses,” said last author Nicola Crosetto, senior researcher at the Department of Medical Biochemistry and Biophysics, Karolinska Institutet.
Journal information: COVseq is a cost-effective workflow for mass-scale SARS-CoV-2 genomic surveillance. Nature Communications, 23 June 2021, DOI: 10.1038/s41467-021-24078-9
South Africa is planning to make vaccines locally using messenger RNA, the breakthrough technology of the global COVID vaccination effort – and once nearly consigned to the dustbin of medical research history.
The World Health Organization (WHO) and its COVAX partners are working with a South African consortium comprising Biovac, Afrigen Biologics and Vaccines, a network of universities and the Africa Centres for Disease Control and Prevention (CDC) to establish its first COVID mRNA vaccine technology transfer hub.
This follows WHO’s global call for Expression of Interest to establish COVID mRNA vaccine technology transfer hubs to scale up production and access to COVID vaccines. The partners will negotiate details with the South African government and public and private partners both local and international.
South African President Cyril Ramaphosa said: “The COVID pandemic has revealed the full extent of the vaccine gap between developed and developing economies, and how that gap can severely undermine global health security. This landmark initiative is a major advance in the international effort to build vaccine development and manufacturing capacity that will put Africa on a path to self determination. South Africa welcomes the opportunity to host a vaccine technology transfer hub and to build on the capacity and expertise that already exists on the continent to contribute to this effort.”
“This is great news, particularly for Africa, which has the least access to vaccines,” said Dr Tedros Adhanom Ghebreyesus, WHO Director-General. “COVID has highlighted the importance of local production to address health emergencies, strengthen regional health security and expand sustainable access to health products.”
The announcement follows the recent visit to South Africa by French President Emmanuel Macron, who gave his country’s commitment to aiding local vaccine production.
“Today is a great day for Africa. It is also a great day for all those who work towards a more equitable access to health products. I am proud for Biovac and our South African partners to have been selected by WHO, as France has been supporting them for years,” said President Macron. “This initiative is the first of a long list to come, that we will keep supporting, with our partners, united in the belief that acting for global public goods is the fight of the century and that it cannot wait.”
Technology transfer hubs are training facilities where the technology is established at industrial scale and clinical development performed. Interested manufacturers from low- and middle-income countries can receive training and any necessary licences to the technology, assisted by the WHO and partners.
Biovac is a bio-pharmaceutical company resulting from a partnership formed with the South African government in 2003 to establish local vaccine manufacturing capability for the provision of vaccines for national health management and security.
Afrigen Biologics and Vaccines is a biotechnology company focuses on product development, bulk adjuvant manufacturing and supply and distribution of key biologicals to address unmet healthcare needs.
The organisations complement one another, and can each take on different roles within the proposed collaboration: Biovac will be the developer while Afrigen is the manufacturer, with a consortium of universities as academic supporters providing mRNA know-how. Africa CDC will provide technical and regional support.
The South African consortium has existing operating facilities with available capacity and experience in technology transfers. It is also a global hub that can start training technology recipients immediately.
The WHO is speaking to a number of pharmaceutical manufacturers about establishing the hub, though the talks are so far mainly with “smaller companies,” said Soumya Swaminathan, WHO’s chief scientist. “We are having discussions with the larger companies with proven mRNA technology,” she added.
The mRNA vaccines may be produced in South Africa within 9 to 12 months, she said. WHO’s call for expressions of interest has so far generated 28 offers to either provide technology for mRNA vaccines or to host a technology hub or both.
It is the first time that messenger RNA technology has been used to make vaccines, which has been used by Moderna and Pfizer/BioNTech. They have proven very effective against the original SARS-CoV-2 strains and even against its more recent variants.
South Korean researchers have found that certain common gut bacteria produce compounds that inhibit SARS-CoV-2.
The research was presented on June 20 at World Microbe Forum, an online meeting of the American Society for Microbiology (ASM), the Federation of European Microbiological Societies (FEMS), and several other societies that taking place online June 20-24.
Previous clinical findings had shown that some patients with moderate to severe COVID experience gastrointestinal symptoms, while others show signs of infection in the lungs only.
“We wondered whether gut resident bacteria could protect the intestine from invasion of the virus,” said Mohammed Ali, a PhD student in Medicine at Yonsei University in South Korea.
To investigate this hypothesis, the researchers screened dominant bacteria inhabiting the gut for activity against SARS-CoV-2. Their efforts revealed that Bifidobacteria, already shown to suppress other bacteria such as H. pylori and have proven active against irritable bowel syndrome, had such activity, said Ali. Bifidobacteria are common in the guts of breast fed infants, which is partly driven by the bifidogenic activities of specific mother milk-derived oligosaccharides
The researchers also searched for potential illness-fighting compounds in databases containing microbially produced molecules, and discovered some that might also be useful against SARS-CoV-2. “To train our model we leveraged previous coronavirus datasets in which several compounds were tested against targets from coronaviruses,” explained Ali. “This approach seems to be significant as those targets share features in common with SARS-CoV-2.”
Ali emphasised the ecological nature of his approach to this work, pointing out that numerous existing antibiotics and cancer therapies are themselves compounds that bacteria use to compete with each other within the gastrointestinal tract, and that these were initially purified from microbial secretions.
“Finding microbes that secrete anti-coronavirus molecules will be a promising method to develop natural or engineered probiotics to expand our therapeutics prevention techniques, to provide a more sustainable way to combat the viral infection,” said Ali.
Brazil’s COVID deaths passed 500 000 in Brazil, days after the US reported passing 600 000 deaths. Experts warn of a worsening outbreak amid slow vaccination and the onset of winter.
President Jair Bolsonaro refuses to back measures like social distancing even as the virus continues to take its toll. With only 11% of adults vaccinated, Brazil’s health institute Fiocruz says the situation is “critical”.
Heavy criticism has been directed at President Bolsonaro for not implementing a co-ordinated national response and for his vaccine scepticism, lockdowns and mask-wearing requirements, which he has sought to loosen.
The country has reported, on average, 70 000 cases and 2 000 deaths daily in the past week. Most new cases were among those aged 20-59, Fiocruz said, warning that the start of winter in the southern hemisphere this week could result in more infections.
Yet governors and mayors have already relaxed nonpharmaceutical interventions. Restaurants, bars and shops have reopened in many cities, while many people in the streets are not wearing face masks or following social distancing.
“People in Brazil are tired and they normalise death now,” Dr Natalia Pasternak Taschner, a microbiologist at the Question of Science Institute, told the BBC, adding that they have a long way to go.
“If we’re not successful in changing the behaviour of people and if we don’t have campaigns for mask wearing, social distancing and vaccinations coming directly from the central government we’re not going to be able to control it.”
On Saturday, protests against President Bolsonaro were held in cities across the country, with demonstrators accusing him of delaying the purchase of vaccines yet prioritising unproven treatments, such as hydroxychloroquine.
More transmissible variants of the virus have driven Brazil’s outbreak, including the one first identified in the Amazon region which is now known as Gamma. Occupancy rate for intensive care unit beds remains at or above 80% in most states, while cities struggle with vaccine supplies.
Faced with a crumbling healthcare system without the relief of lockdowns, a ‘Covid Kit‘ of ivermectin and azithromycin has been touted by the government, and which is widely prescribed. Ironically, its creator, a doctor in Mato Grosso state, died of COVID last September. In a country notorious for its excessive pill-taking, doctors are finding it difficult to recruit people into trials who have not taken ivermectin.
The Brazilian Senate is looking into President Bolsonaro’s handling of the pandemic. The opposition is accusing him of delaying vaccine orders for political reasons, as he has consistently downplayed the pandemic’s severity.
But President Bolsonaro maintains he has done all he can to buy vaccines from several countries, and insists the impacts of a lockdown would be worse than the pandemic.
The president has not commented on the 500 000 deaths although on Twitter, Health Minister Marcelo Queiroga expressed solidarity with relatives of those who had died.
Researchers at the University of Texas Medical Branch have discovered SARS-CoV-2 in the testes of infected hamsters, findings which may explain certain COVID symptoms reported in men.
Clinicians are finding that COVID affects more than just the lungs; some patients have reported testicular pain and some reports have shown decreases in testosterone. Autopsies have also shown evidence of significant disruption of the testes at the cellular level, severe in some cases, and presence of immune cells. Since SARS-CoV-2 has an affinity for ACE-2 receptors, and ACE-2 receptor expression is high in the testes, this could explain why this tissue becomes an infection target for COVID.
“Given the magnitude of the COVID pandemic, it is critical to investigate how this disease can impact the testes, and the potential consequences for disease severity, reproductive health and sexual transmission,” said Dr Rafael Kroon Campos, the study’s lead author and postdoctoral fellow in the laboratory of Dr Shannan Rossi at UTMB.
For a number of years, the Rossi lab had been studying Zika virus infection in the testes and wondered if SARS-CoV-2 could cause a similar disease. Hamsters are common models for COVID since they develop similar signs of disease to humans. Virus was detected in the testes of all infected hamsters during the first week but tapered off. The authors think this may represent what could occur in men with mild to moderate COVID disease.
“These findings are the first step in understanding how COVID impacts the male genital tract and potentially men’s reproductive health,” said Rossi, an associate professor in the Departments of Pathology and Microbiology & Immunology. “We have much more to do before we have the full picture. Moving forward, we will investigate ways to blunt this impact, including using antivirals, antibody therapies and vaccines.”
Future research could also include conditions associated with severe COVID, such as pre-existing conditions like obesity and diabetes and SARS-CoV-2 variants of concern, the study authors said.
