There’s welcome news in the battle against the Ebola virus, an infectious disease that for years had almost no treatments or remedies.
Outbreaks of the deadly Ebola virus flare up in parts of Africa almost every year, and they’re vicious.
The virus kills about half the people it infects. But a new study published in The Lancet Infectious Diseases shows that a promising vaccine (with the complicated name rVSVΔG-ZEBOV-GP) can cut those mortality numbers in half. The results reveal that vaccination doesn’t just help to reduce infections — it also reduces deaths from the virus. www.npr.org/sections/goatsandsoda/2024/02/15/1231249465/ebola-vaccine-cuts-death-rates-in-half-even-if-its-given-after-infection?
“When I first started working in Ebola, we had little more than palliative care to offer patients,” says Rebecca Coulborn, an epidemiologist with Epicentre, the medical research arm of Doctors Without Borders. “I think Ebola is a really cruel disease because the very moment when you want to care for someone who you love is the moment when you shouldn’t touch them.” That’s because people are infectious once they develop symptoms.
Over time, however, researchers have developed ways to fight back against Ebola, including rVSVΔG-ZEBOV-GP, a single-dose intramuscular vaccine that causes cells to make one of the virus’s proteins. “Later, if the person is exposed to Ebola,” explains Coulborn, “their immune system will recognize the viral protein. And this recognition allows the immune system to be prepared to attack the virus and protect the person from Ebola virus disease.”
The vaccine is typically administered to those at highest risk of exposure to the virus — a strategy called ring vaccination that targets “people who are contacts of an Ebola case, contacts of contacts and health-care workers,” says Coulborn. The vaccine is not yet commercially available.
Researchers showed that rVSVΔG-ZEBOV-GP was highly effective at reducing the risk of infection, but no one knew how capable it was of preventing death in someone who was vaccinated after becoming infected during an epidemic. This is what Coulborn and her colleagues set out to determine.
They focused their efforts on the second-largest Ebola outbreak ever recorded, which took place in the Democratic Republic of Congo between 2018 and 2020. Despite the outbreak flaring up in the midst of an active conflict zone, meticulous records were kept.
“Every single Ebola health facility across the entire Ebola epidemic had a standardized, harmonized and compiled list of all admissions,” says Coulborn. This list included 2,279 confirmed Ebola patients, and it recorded whether or not each person had been vaccinated before they got sick — and if so, when they’d received the vaccine. Coulborn then compared how those two groups fared. The result was striking.
Among the unvaccinated, mortality was 56%. But for those who’d received the vaccine, that rate was cut in half. And this was true no matter when someone got vaccinated before the onset of symptoms, whether just a couple days (27.3% fatality risk) or more than three weeks (17.5% fatality risk).
In addition, those who had been vaccinated had less virus circulating in their bodies than those who hadn’t. Coulborn says this may help explain the “lower risk of dying, and it could also have an impact on transmission, reducing the spread of Ebola during an epidemic.”
“So while getting vaccinated as early as possible is the most beneficial,” explains Coulborn, “we now know that vaccination is better late than never.”
Rebecca Coulborn says she feels buoyed by the results — since they offer clear evidence that people who are at risk of contracting Ebola should be vaccinated as early as possible. It’s an opportunity to cut chains of transmission and hobble an outbreak before it gains speed.
Given how little health workers could do when Ebola first emerged in 1976, Coulborn says the power of this vaccine is remarkable.
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A study in China that builds on evidence linking heavy air pollution to increased suicide risk credits air-quality improvements with preventing more than 45,000 suicides. To distinguish pollution’s effect from that of other risk factors, a research team relied on an unusual indicator, incidences of thermal inversions—when warmer air traps cold air and airborne pollutants close to the ground, increasing people’s exposure. The research team found that inversions, typically lasting 2 to 3 hours, were associated with an increase in suicide rates within 1 week but did not have a longer term impact. The research supports previous findings that airborne particles smaller than 2.5 microns (called PM2.5) not only harm physical health, but also quickly alter brain chemistry and are associated with depression and inability to cope with crises. www.science.org/content/article/news-glance-layoffs-jpl-fossils-ancient-innards-darwins-library?
As in most other countries, China’s suicide rate declined during the past decade, in part because of rising prosperity. The study, published this week in Nature Sustainability, attributed nearly 10% of the overall decline in suicide rates between 2013 and 2017 to a campaign China started in 2013 to reduce air pollution.
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Iovance Biotherapeutics (IOVA.O), said on Friday the U.S. health regulator has granted an accelerated approval for its cell therapy for adult patients with advanced melanoma, the first such treatment to be approved for the deadliest form of skin cancer. www.reuters.com/business/healthcare-pharmaceuticals/us-fda-grants-accelerated-approval-iovances-skin-cancer-cell-therapy-2024-02-16/
The agency’s greenlight for the first cell therapy targeting a solid tumour allows use in patients who have been previously treated with other therapies, but their cancer has spread to other parts of the body, and cannot be removed with surgery.
Lifileucel, branded as Amtagvi, is a tumour derived immunotherapy composed of a patient’s own disease-fighting white blood cells known as T-cells, with a specific type called tumour-infiltrating lymphocytes (TIL).
Amtagvi will be sold in the U.S. at a list price of $515,000 per patient, interim CEO Frederick Vogt said on a conference call.
The accelerated approval of Amtagvi is based on safety and effectiveness data from a global study of 73 patients. The therapy will require confirmatory trials to receive the U.S. Food and Drug Administration’s traditional approval.
“The potential market for TIL therapy is sizable, as 90% of all cancers are solid tumours compared to 10% as blood cancers,” Dr Jason Bock, co-founder and CEO of Cell Therapy Manufacturing Centre, said.
The study data showed the objective response rate, a measure of treatment effectiveness, in patients treated with Amtagvi at the recommended dose, was 31.5%.
The therapy’s label comes with a boxed warning for treatment-related mortality, prolonged severe cytopenia, severe infection, and cardiopulmonary and renal impairment.
Vogt said the company does not see the boxed warning having any impact on sales and expects to begin reporting significant revenue in the second quarter of this year.
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Around the globe, disease-causing microbes are finding ways to thwart the drugs that physicians use to treat them. In 2019 alone, bacteria and other microorganisms that had evolved resistance to antimicrobials were responsible for an estimated 1.27 million deaths worldwide.
Now, scientists hope a new synthetic molecule can help by stopping even the most resilient bacteria in their tracks. Many small-molecule antibiotics, including the commonly prescribed clindamycin, target bacterial ribosomes—tiny molecular machines that play an essential role in translating genetic material into proteins. Since this type of antibiotic was first developed, many bacteria have evolved changes to their ribosomes that prevent the molecules from binding. But this new molecule—dubbed cresomycin—has a unique “preorganized” structure that allows it to reliably fasten itself to many different ribosomes, overcoming molecular strategies that render many other antibiotics ineffective.
After testing cresomycin in human cells and mouse models, the scientists found that the drug was effective against a wide range of infectious bacteria, including strains that had previously demonstrated resistance to multiple antibiotics. “Although that is perhaps a daunting consideration,” the researchers report in Science, “we believe that our findings portend favourably for the future discovery of antibacterial agents broadly effective against [resistant bacteria].”
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An analysis of around 1,500 blood proteins has identified biomarkers that can be used to predict the risk of developing dementia up to 15 years before diagnosis. https://www.nature.com/articles/d41586-024-00418-9?
The findings, reported today in Nature Aging, are a step towards a tool that scientists have been in search of for decades: blood tests that can detect Alzheimer’s disease and other forms of dementia at a very early, pre-symptomatic stage.
Researchers screened blood samples from more than 50,000 healthy adults in the UK Biobank, 1,417 of whom developed dementia in a 14-year period.
They found that high blood levels of four proteins — GFAP, NEFL, GDF15 and LTBP2 — were strongly associated with dementia.
“Studies such as this are required if we are to intervene with disease-modifying therapies at the very earliest stage of dementia,” said Amanda Hazelgrove, a neuroscientist at University College London, in a statement to the Science Media Centre in London.
According to the World Health Organization, more than 55 million people worldwide currently live with dementia.
People are often diagnosed only when they notice memory problems or other symptoms. At that point, the disease might have been progressing for years. “Once we diagnose it, it’s almost too late,” says study co-author Jian-Feng Feng, a computational biologist at Fudan University in Shanghai, China. “And it’s impossible to reverse it.”
By screening 1,463 proteins in blood samples from 52,645 people, the authors found that increased levels of GFAP, NEFL, GDF15 and LTBP2 were associated with dementia and Alzheimer’s disease. For some participants who developed dementia, blood levels of these proteins were outside normal ranges more than ten years before symptom onset.
GFAP, a protein that provides structural support to nerve cells called astrocytes, has already been proposed as a diagnostic marker for Alzheimer’s disease, as has GDF15.
The latest study finds that people with high levels of GFAP in their blood are more than twice as likely as people with normal levels to develop dementia, and are nearly three times as likely to develop Alzheimer’s.
The authors used machine learning to design predictive algorithms, combining levels of the four protein biomarkers with demographic factors such as age, sex, education level and family history. They trained the model on information from two-thirds of the study participants, and tested its performance using data from the remaining 17,549 people.
The model predicted the incidence of three subtypes of dementia, including Alzheimer’s disease, with about 90% accuracy, using data from more than ten years before participants were officially diagnosed.
The authors say their findings could be used to develop blood tests that identify people at risk of developing dementia. Other researchers caution that the new biomarkers need further validation before being used as clinical screening tools.
The study “needs to be replicated and biomarkers that enable us not only to screen for disease risk but also to differentiate between diseases should be a priority”, said Heslegrave.
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Lalita Panicker is Consulting Editor, Views and Editor, Insight, Hindustan Times, New Delhi
