by tyler | Apr 5, 2023 | CNN, health
Snoring, snorting, tossing and turning, napping for a long time during the day, waking up during the night, and sleeping too little or even too much all contribute to poor-quality sleep and may raise your risk for stroke, according to a new study.
In fact, researchers found the more sleep problems you have, the greater the risk of stroke.
“Having more than five of these symptoms may lead to five times the risk of stroke compared to those who do not have any sleep problems,” said study author Christine McCarthy of the University of Galway in Ireland in a statement.
“The findings are consistent with prior research linking unhealthy sleep to high blood pressure and to impairments to blood vessels, which are risk factors for stroke,” said sleep specialist Kristen Knutson, an associate professor of neurology and preventive medicine at Northwestern University’s Feinberg School of Medicine in Chicago. She was not involved in the study.
One reason may be the impact of short, fragmented sleep and sleep disorders such as sleep apnea on the body’s ability to regulate metabolism, blood pressure and inflammation, which are all risk factors for stroke, said Dr. Phyllis Zee, director of the Center for Circadian and Sleep Medicine at Northwestern’s medical school, who was not involved in the study.
“Poor sleep can impair the natural blood pressure dipping that occurs during night time sleep and contribute to hypertension — an important risk factor for stroke and cardiovascular disease,” Zee said via email. “In other population based research, similar relationships have been reported between poor sleep health and disorders such as diabetes, heart disease and dementia.”
The study, published Wednesday in the journal Neurology, analyzed data from more than 4,500 people participating in INTERSTROKE, a large international case-control study of patients who have experienced a stroke.
Nearly 1,800 participants in the study had an ischemic stroke, the most common kind, in which a blood clot blocks an artery leading to the brain. Another 439 people had an intracerebral hemorrhage in which arteries or veins in the brain rupture, causing bleeding into brain tissue.
Participants in the study were then matched by age and sex to people who had no history of stroke. Both groups answered questions about their sleep quality and behavior, and the two groups were compared.
Results showed people who slept less than five hours a night on average were three times more likely to have a stroke than those who got seven hours of sleep — the recommended minimum for adults.
On the flip side, sleeping more than nine hours a night on average was associated with a twofold increase in stroke risk, according to a statement on the study.
The results held true even after adjustments to eliminate other issues that can lead to stroke, including depression, alcohol abuse, smoking and a lack of physical activity, according to the study.
Having sleep apnea — a condition in which people stop breathing multiple times per hour — was associated with a threefold increase in stroke risk, the statement said.
“Sleep apnea can alter the pathways involved in the regulation of coagulation factors that can increase the risk of strokes,” Zee said.
Snoring or snorting, which can both be signs of untreated sleep apnea, were also risky. People who snored were 91% more likely to have suffered a stroke, while those who snorted were almost three times as likely to have had a stroke than those who did not.
Napping was also a risk factor, the statement said. People who on average napped more than an hour were 88% more likely to suffer a stroke than those who did not. However, taking a planned nap of less than an hour was not associated with an increased stroke risk, the study said.
It’s important to note that the research could only show an association between sleep problems and stroke, not causation, said Dr. Andrew Freeman, director of cardiovascular prevention and wellness at National Jewish Health in Denver.
“The question remains: Is poor quality sleep causative? Or is it simply associated with a cluster of bad health habits that would lead somebody to have a higher stroke risk?” asked Freeman, who was not involved in the research.
“Are they under a lot of stress? Are they drinking huge amounts of caffeine and then not sleeping? Maybe they’re not exercising very much, and we know that exercise promotes good quality sleep,” Freeman said. “It’s hard to tease out all the factors that might contribute.”
Practicing good sleep hygiene, eating a healthy diet and getting regular exercise are all key ways to reduce the negative impact of sleep disorders and reduce stroke and cardiovascular risk, Freeman said.
“What I always tell people is, you know, getting about seven hours a night of uninterrupted sleep is associated with the least amount of cardiovascular disease,” he said.
It’s important to prioritize getting those seven to eight hours of uninterrupted sleep each night on a regular basis, Zee said. Doing so means going to bed and waking at the same time every day, even on weekends.
“Regular exposure to light in the morning and afternoon can also improve sleep quality,” she said, adding that anyone suffering from snoring, insomnia or excessive sleepiness during the day should talk to a sleep specialist.
The bedroom should be used for sleeping and intimacy only, Freeman added.
“Don’t hang out in there and watch TV or read books or do work in there,” he said. “Keep a notebook next to the bed so if you wake up in the middle of the night you can write down what comes to mind. Diffuse any worries you have by meditating on it and do your best to let things go.”
Don’t drink alcohol or eat at least three hours before bed to avoid gastric distress that might wake you up, Zee suggested.
“It’s also important to exercise, preferably in the morning,” Freeman added. “The one true medicine that works always is improving one’s lifestyle to include healthy behaviors.”
by tyler | Apr 5, 2023 | CNN, health
Alzheimer’s disease strikes women harder than men — over two-thirds of those who descend into dementia’s devastating twilight are female at birth. That’s likely due to biological reasons that remain poorly understood, according to the Alzheimer’s Association.
One key piece of the enigma: Women lose sexual hormones such as estrogen when they undergo menopause, either naturally through the body’s decreased production or by removal of the ovaries via surgery. However, just how the loss of those hormones and the impact of hormone replacement therapy, or HRT, affects dementia risk is also unclear.
A new study may have uncovered a piece or two of the puzzle. Women who underwent early (age 40 to 45) or premature (before age 40) menopause or women who began hormone replacement therapy more than five years after menopause had higher levels of tau in their brains, according to the study published Monday in the journal JAMA Neurology.
Tau tangles, along with plaques made up of beta-amyloid proteins, are hallmark signs of Alzheimer’s disease.
“This is the first study showing a delayed use of hormone therapy seems to be associated with increased levels of Alzheimer’s disease markers in the brain,” said lead author Gillian Coughlan, a research fellow in neurology at Massachusetts General Hospital in Boston.
However, these changes only occurred in women who already had higher levels of beta-amyloid in their brain tissue, Coughlan told CNN.
“Most of the associations we saw between menopause and tau protein occurred in the context of high amyloid,” Coughlan said. “Now a large portion of the older population do accumulate amyloid as they get older — it’s not that uncommon.”
Tau deposits, however, are more uncommon, she said, adding that it takes both tau tangles and beta-amyloid to develop Alzheimer’s disease. “Usually if you’ve a combination of beta-amyloid and tau, then you would typically develop cognitive decline within a few years,” Coughlan said.
“What we found is women who have early menopause or have a very late use of hormone therapy might be at higher risk, but only if they were already on the Alzheimer’s disease continuum, with elevated levels of amyloid,” she said. “Women with very low levels of amyloid and early menopause did not have such an association.”
The study also found that women who began hormone therapy “at the right time, proximal to menopause age, didn’t have higher or lower tau proteins in the brain,” Coughlan said. “This is good as it means we may still be able to use hormone therapy to treat severe menopausal symptoms.”
Dr. Richard Isaacson, an Alzheimer’s preventive neurologist at the Institute for Neurodegenerative Diseases, considered the scientific paper important.
“While it’s not the first time a study has shown that early treatment with hormone replacement therapy may be more protective for a women’s brain, it did suggest for the first time that greater amounts of tau protein may be associated with later initiation of hormone treatment,” said Isaacson, who was not involved in the study.
“This study doesn’t show that hormone therapy causes Alzheimer’s. The researchers didn’t look at whether the participants went on to develop symptoms of dementia and we can’t be sure of cause and effect in this kind of research,” said Sara Imarisio, head of strategic initiatives at Alzheimer’s Research UK, in a statement.
“Hormone therapy provides important benefits to many women, helping to combat the symptoms that menopause can bring,” said Imarisio, who was not involved in the study. “Women who take, or are thinking of taking, hormone therapy should not be put off by these results, and anyone concerned about the effects of this treatment should speak to their doctor.”
The average age of menopause onset — defined as when a woman hasn’t had a period for 12 months in a row — is 51, although women can naturally go into menopause between the ages of 40 and 58, according to the North American Menopause Society. Symptoms such as hot flashes and night sweats can occur years in advance, in what is called perimenopause.
Hormone replacement therapy has been a loaded topic for many women since early, misguided results were published in 2002 from a study called the Women’s Health Initiative clinical trial. That preliminary analysis found an estrogen and progestin combo — the type of HRT prescribed at the time — increased the risk of heart disease as well as stroke, blood clots, dementia and breast cancer. The study was halted early due to the dangers.
Fallout was dramatic. By the end of the year, hormone therapy use dropped 30% when analyzed by insurance claims. By 2009, hormone therapy claims had dropped more than 70%.
Ten years later, the Women’s Health Initiative findings were debunked. Because the original analysis looked at women age 65 and older, who were already at greater risk for heart attacks, blood clots and stroke, the initial 2002 results were flawed because they failed to consider a woman’s age at the start of replacement therapy.
But the damage was done. Even today, many doctors are uncomfortable prescribing the use of hormone therapy, leaving many women to suffer through devastating symptoms without recourse.
Current medical guidelines suggest the benefits of hormone therapy for hot flashes, night sweats, vaginal pain and dryness, urinary issues, and bone loss outweigh the risks for women younger than 60 who are within 10 years of the onset of menopause — and who have no known or suspected history of breast cancer, blood clots, stroke or other contraindications.
It’s a different story for women who are older than 60 or who start hormone therapy more than 10 years after the onset of menopause. “The benefit-risk ratio appears less favorable because of the greater absolute risks of coronary heart disease, stroke, venous thromboembolism, and dementia,” according to the 2022 hormone therapy position statement of The North American Menopause Society.
In the new JAMA Neurology study, a team of researchers from Boston-based Massachusetts General Hospital and Brigham and Women’s Hospital analyzed brain scans of 193 women and 99 men with normal cognitive function for beta-amyloid and tau pathology.
That may sound like a small study, but it isn’t, Coughlan said: “When using brain scans to actually look at disease in the brain, this is considered a large sample size.”
The study found women had more tau buildup in several parts of the brain than men of a similar age, said Tara Spires-Jones, professor of neurodegeneration and deputy director of the Centre for Discovery Brain Sciences at the University of Edinburgh in Scotland. She wasn’t involved in the study.
“Further, females had higher tau burden than males when they also have amyloid pathology in the brain,” Spires-Jones said in a statement.
Women in the new study all used the type of hormone therapy — the estrogen and progestin mix — that was used by the women in the Women’s Health Initiative clinical trial that caused so much controversy, Coughlan said.
“If (our study) is replicated, we may have found a potential biological basis for the results of the Women’s Health Initiative clinical trial, which found women 65 and above were more likely to develop dementia later in life if they took that one type of hormone therapy,” she said.
However, today women have many other options for hormone replacement, depending on their individual needs.
The study had some limitations — most participants were White and the study did not say who then went on to develop dementia, experts said. In addition, there were not enough people in the study with a genetic risk for Alzheimer’s, said Dr. Liz Coulthard, an associate professor in dementia neurology at the University of Bristol in the United Kingdom, who was not involved in the study.
“Recently we found out that HRT might have different effects in people at high genetic risk (apoE4 gene positive), but this is not featured here,” Coulthard said in a statement.
“The results here are scientifically interesting,” she added. “But research into the relationship between HRT, menopause and Alzheimer’s is beset by multiple small studies, all confounded by the different reasons people are prescribed HRT and accuracy of memory for menopause age and HRT use.
“As a result, women are receiving conflicting or poorly justified advice as to whether HRT use may be helpful or not for future brain health,” Coulthard said. “A balanced, well-powered trial of HRT over many years is the only way we will really understand whether HRT is harmful to brain health.”
by tyler | Apr 5, 2023 | CNN, health
A record number of people are dying from firearm injuries in the US, and new research suggests that shootings are becoming more lethal, too.
Most victims of fatal firearm injuries die at the scene of the shooting, before they can be treated in a health care setting. But that has become increasingly common over the past two decades.
About 57% of firearm fatalities in 2021 occurred at the scene of the shooting, up 9% since 1999, according to a research letter published Wednesday in the JAMA Surgery journal. For this analysis, researchers used data from the US Centers for Disease Control and Prevention and excluded suicides and other self-inflicted firearm injuries.
Nearly 49,000 people died from firearm injuries in the US in 2021, CDC data shows – an unprecedented surge of about 23% over two years during the Covid-19 pandemic.
And a shift in the type of firearms that are being bought and used is a key factor making shootings more lethal, experts say.
“It’s leaning more and more towards military-grade, higher velocity, higher lethality type of weapons,” said Dr. Eric Fleegler, an emergency physician at Boston Children’s Hospital.
“That includes larger magazine capacity so they can shoot more bullets, the ability to fire them at faster rates, and quite frankly, just bigger, faster bullets which cause more damage to a human body.”
Federal data shows that handguns are the most common murder weapon, used in more than half of all homicides that involve firearms. But rifles, such as the AR-15, are becoming more frequently used.
Nearly 4% of firearm homicides in 2021 involved a rifle, killing 447 people, according to data from the Federal Bureau of Investigation. That’s more than twice as many deaths and nearly twice as common compared to firearm homicides in 2015.
Other external factors could also play a role in the location where a victim dies, such as increasing demand for ambulances that could affect emergency transportation options.
Still, experts say that more – and better – data on gun violence is needed.
In the CDC data, for example, definitions to help differentiate location of death were lacking and many were coded as “other” or “unknown.”
And the true scope of America’s gun epidemic is far broader than the deaths it causes, experts say.
“Deaths from firearm injuries are horrible tragedies, but they are unfortunately just the tip of the iceberg,” said Fleegler, who has studied gun violence but was not involved in this research.
There are many others who suffer physically from gunshot wounds and a deep emotional toll on families and communities, he said, and more robust data is needed to understand that.
While there are more questions to be answered, experts say that this new research adds to evidence that an important step to reducing gun violence will involve addressing the types of guns that are available.
“It reiterates that maybe there should be a look at solutions which limit the magazine capacity and access to high-caliber weapons, as well,” said Ari Davis, a policy advisor at the Johns Hopkins Bloomberg School of Public Health Center for Gun Violence Solutions.
by tyler | Apr 4, 2023 | CNN, health
The US National Institute on Aging is moving forward with efforts to build a real-world Alzheimer’s disease database as part of its aim to improve, support and conduct more dementia research.
Last month, the agency, part of the National Institutes of Health, posted a notice of the grant for the six-year database project, setting its earliest start date as April 2024.
The NIH confirmed Tuesday that plans are underway to fund the Alzheimer’s disease and Alzheimer’s disease-related dementias’ real-world data platform.
The National Institute on Aging intends to commit $50 million per year, starting in fiscal year 2024, to fund one award.
The nonprofit Alzheimer’s Association is among those planning to apply for the grant.
“The newly-announced NIA funding for a large-scale Alzheimer’s disease research database is truly exciting and a very important step forward for our field, and the Alzheimer’s Association will apply for that grant,” Maria C. Carrillo, Alzheimer’s Association chief science officer, said in an email Tuesday.
“The Association is already leading ALZ-NET, which is a national network of physicians that is collecting data – including measures of cognition, function and safety – for patients treated with new FDA-approved Alzheimer’s treatments,” Carrillo said. “The NIA funding could expand ALZ-NET’s scope to the benefit of all stakeholders.”
She added that the Alzheimer’s Association believes everyone should have access to treatments, regardless of their registration status.
The real-world database “aims to transform” the Alzheimer’s disease research enterprise “by serving as a central hub of research access,” the National Institute on Aging said last week in its announcement of a webinar about the project that’s scheduled for April 19.
According to the announcement, the aim of the data registry is to provide a comprehensive and diverse database that can “improve applicability and generalizability of findings,” be used as a tool for researchers and allow scientific questions to be answered more quickly.
Last year, the National Institute on Aging convened an exploratory workshop to discuss gaps in real-world data and opportunities to expand real-world data sources for dementia research.
Alzheimer’s disease, a brain disorder that affect memory and thinking skills, is the most common type of dementia, the NIH says.
More than 6 million Americans are living with dementia caused by Alzheimer’s disease, according to the Alzheimer’s Association, and the number of people affected is projected to double in the next two decades, rising to 13 million in 2050.
by tyler | Apr 4, 2023 | CNN, health
As we mark Stress Awareness Month in April, I know there’s so much to be stressed out—mass shootings, wars around the world, the pandemic’s long-term effects and the daily stresses of living and working in the 21st century. I’m sure you’ve got your list.
Everyone experiences stress at different points in their life. But when is stress a problem that requires our attention? What symptoms should people be on the lookout for? What are the health impacts of long-term stress? What are healthy and unhealthy coping mechanisms? And what techniques can help in addressing—and preventing—stress?
Fresh from dropping off my kid at school late (sorry, kid, my fault), I was looking forward to this advice from CNN Medical Analyst Dr. Leana Wen. Wen is an emergency physician and professor of health policy and management at the George Washington University Milken Institute School of Public Health. She previously served as Baltimore’s Health Commissioner and as Chair of Behavioral Health Systems Baltimore.
CNN: Let’s start with the basics. What exactly is stress?
Dr. Leana Wen: There is no single definition of stress. The World Health Organization’s definition refers to a state of worry or tension caused by a difficult situation. Many people experience stress as mental or emotional strain. Others also have physical manifestations of stress.
Stress is a natural reaction. It’s a human response that prompts us to respond to challenges and perceived threats. Some stress can be healthy and can prompt us to fulfill obligations. Perceived stress can spur us to study for a test or complete a project by a certain deadline. Virtually everyone experiences that kind of stress to some extent.
CNN: Why can stress be a problem?
Wen: The same human response that motivates us to work hard and finish a project can also lead to other emotions, like not being able to relax and becoming irritable and anxious. Some people develop physical reactions, like headaches, upset stomach and trouble sleeping. Longer-term stress can lead to anxiety and depression, and it can worsen symptoms for people with pre-existing behavioral health conditions, including substance use.
CNN: What are symptoms of stress that people should be on the lookout for?
Wen: In addition to feeling irritable and anxious, people experiencing stress can also feel nervous, uncertain and angry. They often express other symptoms, including feeling a lack of motivation; having trouble concentrating; and being tired, overwhelmed and burnt out. Many times, people in stressful situations will report being sad or depressed.
It’s important to note that depression and anxiety are separate medical diagnoses. Someone with depression and/or anxiety could have their symptoms exacerbated when they are undergoing times in their life with added stress. Long-term stress can also lead to depression and anxiety.
One way to think about the difference between stress versus anxiety and depression is that stress is generally a response to an external issue. The external cause could be good and motivating, like the need to finish a project. It could also be a negative emotional stress, like an argument with a romantic partner, concerns about financial stability or a challenging situation at work. Stress should go away when the situation is resolved.
Anxiety and depression, on the other hand, are generally persistent. Even after a stressful external event has passed, these internal feelings of apprehension, unworthiness and sadness are still there and interfere with your ability to live and enjoy your life.
CNN: What are the health impacts of long-term stress?
Wen: Chronic stress can have long-term consequences. Studies have shown that it can raise the risk of heart disease and stroke. It’s associated with worse immune response and decreased cognitive function.
Individuals experiencing stress are also more likely to endorse unhealthy behaviors, like smoking, excessive drinking, substance use, lack of sleep and physical inactivity. These lifestyle factors in turn can lead to worse health outcomes.
CNN: What techniques can help in addressing stress?
Wen: First, awareness is important. Know your own body and your reaction to stress. Sometimes, anticipating that a situation may be stressful and being prepared to deal with it can reduce stress and anxiety.
Second, identifying symptoms can help. For example, if you know that your stress reaction includes feeling your heart rate increase and getting agitated, then you can detect the symptoms as they occur and become aware of the stressful situation as it’s occurring.
Third, know what stress relief techniques work for you. Some people are big fans of mindfulness meditation. Those, and deep breathing exercises, are good for everyone to try.
For me, nothing beats stress relief like exercise. For me, what helps is exercising, in particular swimming. Aerobic exercise is associated with stress relief, and mixing it up with high-intensity regimens can help, too.
A lot of people have other specific techniques that help them. Some people clean their house, organize their closets or work in their gardens. Others spend time walking in nature, writing in a journal, knitting, playing with their pets or cycling.
I’d advise that you experiment with what works, take stock of existing techniques that help you and incorporate some of those practices into your regular routine. Then, in times of stress, they are good tools to turn to that you know will help you.
CNN: What unhealthy copings strategies should people avoid?
Wen: Definitely. There are things people turn to in an effort to make themselves feel better in the short-term that can actually make things worse. Excessive alcohol intake, using drugs and smoking aren’t healthy coping strategies. It’s the same with staying up all night, binge-eating and taking out your frustration on loved ones. These have wide-ranging consequences, and you should reconsider them if they have been your go-to coping mechanisms in the past.
CNN: When is it time to seek help?
Wen: If the stress you are feeling is consistently interfering with your work, social or personal life or if you are experiencing signs and symptoms of depression, anxiety and other mental health disorders, it’s time to seek help.
Consider speaking with your primary care physician to get a referral to a therapist. Your workplace may have an Employee Assistance Program that you can turn to, too. And the federal mental health crisis hotline number, 988, is another resource.
This April, for Stress Awareness Month, I hope we can all assess our own stress levels as well as our reaction to stress. We should recognize what helps us to reduce and alleviate stress as we aim to improve our physical and emotional well-being.
by tyler | Apr 3, 2023 | CNN, health
Scientists in Germany say they’ve been able to make a nasal vaccine that can shut down a Covid-19 infection in the nose and throat, where the virus gets its first foothold in the body.
In experiments in hamsters, two doses of the vaccine, which is made with a live, but weakened form of the coronavirus that causes Covid-19, blocked the virus from copying itself in the animals’ upper airways—achieving so-called “sterilizing immunity,” and preventing illness, a long sought goal of the pandemic.
While this vaccine has several more hurdles to clear before it gets to a doctor’s office or drug store, other nasal vaccines are already in use, or are nearing the finish line in clinical trials.
China and India both rolled out vaccines given through the nasal tissues last fall, though it’s not clear how well they may be working. Studies on the effectiveness of these vaccines have yet to be published, leaving the world to wonder whether this approach to protection really works in people.
The US has reached something of a stalemate with Covid-19. Even with the darkest days of the pandemic behind us, hundreds of Americans are still dying daily, as the infection continues to simmer in the background of our return to normal life.
As long as the virus continues to spread among people and animals, there’s always the potential for it mutate into a more contagious or more damaging version of itself. And while Covid infections have become manageable for most healthy people, they may still pose a danger to vulnerable groups—such as the elderly and immunocompromised.
Researchers hope next-generation Covid-19 vaccines, which aim to shut down the virus before it ever gets a chance to make us sick, and ultimately – scientists hope – prevent the spread of the infection, could make this our newest resident respiratory infection less of a threat.
One way scientists are trying to do that is by boosting mucosal immunity, beefing up immune defenses in the tissues that line the upper airways, right where the virus would land and begin to infect our cells.
It’s a bit like stationing firefighters underneath the smoke alarm in your house, says study author Emanuel Wyler, a scientist at the Max Delbruck Center for Molecular Medicine in the Helmholtz Association in Berlin.
The immunity that’s created by shots works throughout the body, but it resides primarily in the blood. That means it may take longer to mount a response.
“If they are already on site, they can immediately eliminate the fire, but if they’re like two miles away, they first need to drive there and by that time, one-third of the house is already in full flames,” Wyler said in an interview with CNN.
Mucosal vaccines are also better at priming a different kind of first responder than injections do. They do a better job of summoning IgA antibodies, which have four arms to grab onto invaders instead of just the two arms that the y-shaped IgG antibodies have. Some scientists think IgA antibodies may be less picky about their targets than IgG antibodies, which makes them better equipped to deal with new variants.
The new nasal vaccine takes a new approach to a very old idea – weakening a virus so it’s no longer a threat, then giving it to people so their immune systems can learn to recognize and fight it off. The first vaccines using this approach date back to the 1870s, against anthrax and rabies. Back then, scientists weakened the agents they were using with heat and chemicals.
The researchers manipulated the genetic material in the virus to make it harder for cells to translate. This technique, called codon pair de-optimization, hobbles the virus so it can be shown to the immune system without making the body sick
“You could imagine reading a text… and every letter is a different font, or every letter is a different size, then the text is much harder to read. And this is basically what we do in codon pair deoptimization,” Wyler said in an interview with CNN.
In the hamster studies, which are published today in the journal Nature Microbiology, two doses of the live, but weakened nasal vaccine created a much stronger immune response than either two doses of an mRNA-based vaccine or one that uses an adenovirus to ferry the vaccine instructions into cells.
The researchers think the live, but weakened vaccine probably worked better because it closely mimics the process of a natural infection.
The nasal vaccine also previews the entire coronavirus for the body, not just its spike proteins as current Covid-19 vaccines do, so the hamsters were able to make immune weapons against a wider range of targets.
As promising as all this sounds, vaccine experts say caution is warranted. This vaccine still has to pass more tests before it’s ready for use, but they say the results so far look encouraging.
“They did a very nice job. This is obviously a competent and thoughtful team that did this work, and impressive in the scope of what they did. Now it just needs to be repeated,” perhaps in primates and certainly in humans before it can be widely used, said Dr. Greg Poland, who designs vaccines at the Mayo Clinic. He was not involved in the current research.
The study began in 2021, before Omicron was around, so the vaccine tested in these experiments was made with the original strain of the virus. In the experiments, when they infected animals with Omicron, the live, but weakened nasal vaccine still performed better than the others, but it’s ability to neutralize the virus was diminished. Researchers think it will need an update.
It also needs to be tested in humans, Wyler says they’re working on that. The scientists say they’ve partnered with a Swiss company called RocketVax to start phase one clinical trials.
Other vaccines are further along. But the progress has been “slow and halting,” Poland said. Groups working on these vaccines are struggling to raise the steep costs of getting a new vaccine to market, and they’re doing it in the setting where people think the vaccine race has been won and done.
In reality, Poland said, we’re far from that. All it would take is another Omicron-level shift in the evolution of the virus and we could be back at square one, with no tools against the coronavirus.
“That’s foolish. We should be developing a pan-Coronavirus vaccine that does induce mucosal immunity and that is long lived,” he said.
At least four nasal vaccines for Covid-19 have reached late-stage testing in people, according to the World Health Organization’s vaccine tracker.
The nasal vaccines already in use in China and India rely on harmless adenoviruses to ferry their instructions into cells, though effectiveness data for these has not been published.
Two other nasal vaccines are finishing human studies.
One, a recombinant vaccine that can be produced cheaply in chicken eggs, the same way as many flu vaccines are, is being put through its paces by researchers at Mount Sinai in New York City.
Another, like the German vaccine, uses a live but weakened version of the virus. It’s being developed by a company called Codagenix. Results of those studies, which were carried out in South America and Africa, may come later this year.
The German team says they’re anxiously watching for the Codagenix data.
“They will be very important in order to know where whether this kind of attempt is basically promising or not,” Wyler said.
They have reason to worry. Respiratory infections have proved to be tough targets for inhaled vaccines.
FluMist, a live, but weakened form of the flu virus, works reasonably well in children, but doesn’t help adults as much. The reason is thought to be that adults already have immune memory for the flu, and when the virus is injected into the nose, and so the vaccine mostly boosts what’s already there.
Still, some of the most potent vaccines such as the vaccine against measles, mumps and rubella use live, attenuated viruses, so it’s a promising approach.
Another consideration is that live vaccines can’t be taken by everyone. People with very compromised immunity are often cautioned against using live vaccines because even these very weakened viruses may be risky for them.
“Although it’s strongly attenuated, it’s still a real virus,” Wyler said, so it would have to be used carefully.
