Despite having 37 new mutations in the viral spike protein, there does not appear to be any deaths associated with Omicron, although it’s spreading rapidly in South Africa.
The jury’s still out on how dangerous and infectious the Omicron variant of SARS-CoV-2 is. Despite 37 new mutations in the viral spike protein, there are no deaths associated with the variant although it’s spreading rapidly in South Africa.
What Omicron Can Show about COVID Evolution
Viruses mutate, and SARS-CoV-2 and its various variants demonstrate that. HIV, for example, quickly mutates, often resulting in resistance to antiviral drugs. Researchers tracking SARS-CoV-2 evolution are looking for two categories of changes: mutations that make it more transmissible and the virus’s ability to overcome a host’s immune response.
Early genome sequencing observed SARS-CoV-2 gaining about two single-letter mutations per month, about half seen with influenza viruses and a quarter of HIV. This is due to enzymes coronaviruses have that correct genomic errors that are rare in other RNA viruses. But earlier mutations didn’t seem to affect the virus’s behavior. It wasn’t until Delta and Alpha that major leaps in transmissibility were observed.
They note, however, that it has been unpredictable. Alpha was one of the most infectious early variants, and many researchers expected an offshoot of Alpha to come along, but instead, Delta emerged.
“That absolutely proved not to be the case,” says Paul Bieniasz, Ph.D., a virologist at Rockefeller University in New York City. “Delta came out of the left field.”
The same researchers expected Delta and its descendants would make up most global COVID-19 cases. Now Omicron has injected another element of unpredictability. How fast it is arising in South Africa suggests it has a survival advantage over Delta. It has some of the mutations that Delta has related to infectivity. But they don’t think that’s the sole reason for its rapid growth. They think it might be because Omicron can infect people immune to Delta via vaccination or previous infections. Still, they don’t know yet. More information is coming in all the time, but it will likely be a couple more weeks before a full picture of Omicron develops.
Some virologists suspect that additional mutations to the spike protein could decrease the virus’s ability to recognize and bind to human host cells. The spike protein attaches to host cells’ ACE2 receptors, and Dr. Jason McLellan, a structural biologist at the University of Texas at Austin, suspects the spike protein may only tolerate so much change before it stops doing its job of attaching to the ACE2 receptors.
Others think it’s possible that with the population being repeatedly exposed to different versions of the spike protein, we will build up “a wall of immunity” against the virus in general.
Prof. Aris Katzourakis, a viral evolutionary specialist at the University of Oxford, points out how a virus evolves and likely how COVID-19 will transition from pandemic to endemic—more common, less deadly, like cold and flu—is not simple. “A lot of people have a flat horizontal line in their head,” he says, “which is not what endemic infections do.”
COVID-19 will likely cause outbreaks and epidemics of different extremes, just like influenza or other respiratory infections.
A Chewing Gum to Decrease COVID-19 Transmission
Researchers at the University of Pennsylvania are working to develop chewing gum that could reduce the risk of COVID-19 transmission. It is mixed with a plant-grown protein that acts as a “trap” for SARS-CoV-2, the virus that causes COVID-19.
“SARS-CoV-2 replicates in the salivary glands, and we know that when someone who is infected sneezes, coughs, or speaks some of that virus can be expelled and reach others,” said Henry Daniell, Ph.D., at Penn. “This gum offers an opportunity to neutralize the virus in the saliva, giving us a simple way to possibly cut down on a source of disease transmission.”
GSK and Medicago Announce Positive Phase III Data from Plant-Based COVID-19 Vaccine
GlaxoSmithKline and Medicago announced positive results from the Phase III trial of Medicago’s plant-based COVID-19 vaccine combined with GSK’s adjuvant. The trial was run by 24,000 participants in six countries. The vaccine also demonstrated efficacy in several variants, which are the ones predominantly circulating. The vaccine rate against all variants was 71%. In people with no previous exposure, it was 75.6%, and 75.3% against Delta, 88.6% against Gamma. No Alpha, Lambda, Mu, or Omicron cases were circulating during the study.
GSK and Vir’s Monoclonal Antibody Effective Against Omicron Variant
GSK also published, along with Vir Biotechnology, preclinical data on bioRxiv on the effectiveness of its monoclonal antibody sotrovimab. The antibody maintained in vitro activity against the full known Omicron spike protein in the study. It was performed via pseudo-virus testing of the combined known mutations of Omicron, which included the 37 known mutations.
“From the outset of our collaboration with Vir, we hypothesized that sotrovimab would have a high barrier to resistance and thus could deliver best-in-class potential for the early treatment of patients with COVID-19,” said Hal Barron, M.D., chief scientific officer and president of Research and Development for GSK. “These preclinical data demonstrate the potential for our monoclonal antibody to be effective against the latest variant, Omicron, plus all other variants of concern defined to date by the WHO, and we look forward to discussing these results with regulatory authorities around the world.”
Mix-and-Match of Pfizer-BioNTech and AstraZeneca-Oxford Vaccines Works Well
Yet another study suggests the effectiveness and safety of mixing and matching different vaccines. A study out of the U.K.. found that mixing vaccines with either the AstraZeneca or Pfizer-BioNTech vaccines was at least as effective as two doses of the same vaccine. The study was published in the Lancet and was conducted by the University of Oxford. They tested vaccine combinations on more than 1,000 volunteers over the age of 50.
They noted that the Moderna and Novavax vaccines increased immunity after the AstraZeneca-Oxford vaccine, compared to a second AstraZeneca-Oxford shot, but the Moderna increased antibodies after the Pfizer-BioNTech vaccine compared to the standard two-shot regiment of Pfizer-BioNTech.
“There’s a great amount of flexibility” with the first two doses, said Matthew Snape, a professor of pediatrics and vaccinology at the University of Oxford. “Especially in low-income countries, that’s very relevant to having a flexible and adaptable immunization program.”
Stainless Steel that Kills COVID-19
Scientists at the University of Hong Kong have developed stainless steel that kills infectious viruses, including COVID-19. The metal has a higher copper content, meaning it “exhibits significant antiviral properties.” The product reduces 99.75% of viable COVID-19 on its surface within three hours, and 99.99% within six hours, and down to no traces after 24 hours. The stainless steel also kills the H1N1 influenza A virus and E. coli bacteria.
U.S. Expands Aid for International Vaccine Access
The U.S. Agency for International Development (USAID) launched a new program, the U.S. Government’s Initiative for Global Vaccine Access (Global VAX). The program will invest $315 million for vaccine readiness programs and $10 million for in-country vaccine manufacturing. It will also invest $75 million to deliver other life-saving resources, such as oxygen. It will focus first on support to countries in sub-Saharan Africa.
Although the U.S. has donated about 1.2 billion vaccine doses worldwide, less than one-quarter have been delivered. Distribution and supply chain remains a problem, and that will be one of the priorities of the Global VAX program.
Court Orders Pennsylvania Court to Administer Ivermectin
Keith Smith is on a ventilator from COVID-19 at the University of Pennsylvania Medical Center Memorial Hospital. His wife, Darla, filed a lawsuit in York County Court, requesting the courts force the hospital to treat her husband with ivermectin. The drug is an anti-parasitic that appears to have some anti-inflammatory characteristics but is not authorized by the U.S. Food and Drug Administration (FDA) to treat COVID-19.
The court order is confusing. York County Judge Clyde Vedder denied Darla Smith’s request for an emergency injection to require UPMC to give the drug. But a paragraph in the court order directed the hospital to let the physician who had prescribed ivermectin, or another doctor or registered nurse, to administer it under the doctor’s “guidance and supervision.”
The man received his first dose of ivermectin on Sunday night.
