First-line immune defences against COVID-19 are short-lived and may explain reinfection
A new study finds that antibodies produced in the nose decline nine months after COVID-19 infection, while antibodies found in the blood last at least a year.
Newswise — A new study finds that antibodies produced in the nose decline nine months after COVID-19 infection, while antibodies found in the blood last at least a year.
Antibodies in the nasal fluid (known as immunoglobulin A, or IgA) provide first-line defence against COVID-19 by blocking SARS-CoV-2 virus when it first enters the respiratory tract. These antibodies are very effective at preventing the virus from entering cells and causing infection.
However, the investigators found that the nasal antibodies were only present in those recently infected and were particularly short-lived against the Omicron variant, compared to earlier variants.
These new findings – which are published in eBioMedicine – may explain why people who have recovered from COVID are at risk of reinfection, and especially with Omicron and its subvariants.
The study also found that vaccination is very effective in creating and boosting antibodies in the blood, which prevent severe disease, but had very little effect on nasal IgA levels.
First author of the study, Dr Felicity Liew, from the National Heart and Lung Institute at Imperial College London, said: “Before our study, it was unclear how long these important nasal antibodies lasted. Our study found durable immune responses after infection and vaccination, but these key nasal antibodies were shorter-lived than those in the blood. While blood antibodies help to protect against disease, nasal antibodies can prevent infection altogether. This might be an important factor behind repeat infections with the SARS-CoV-2 virus and its new variants.”
The researchers note that studies that directly study these nasal antibodies and reinfections are needed to confirm their results.
The research was led by teams from Imperial College London and the University of Liverpool. It studied almost 450 people who had been hospitalised with COVID-19 between February 2020 and March 2021, before the emergence of Omicron variant and prior to vaccine rollout.
The study also found that whilst current vaccines are effective at boosting blood antibody which can prevent serious illness and death, they do not significantly boost nasal IgA antibodies.
The researchers call for the next generation of vaccines to include nasal spray or inhaled vaccines that target these antibodies more effectively. They say that vaccines capable of boosting these antibodies could potentially reduce infections more effectively and prevent transmission.
Co-senior author of the study, Professor Peter Openshaw, from the National Heart and Lung Institute at Imperial College London, said: “Our results highlight a need for nasal spray vaccines that can boost these local antibodies in the nose and lungs. Such vaccines might be able to prevent people from getting infected with the SARS-CoV-2 virus and reduce transmission of the virus between people. This could help us to better control the pandemic and stop new variants emerging.”
He continues: “Our current vaccines are designed to reduce severe disease and death and are dramatically effective in this aim. It’s now essential to also develop nasal spray vaccines that can provide better protection against infection. It’s brilliant that current vaccines mean fewer people are becoming seriously ill, but it would be even better if we could prevent them from getting infected and transmitting the virus.”
The study analysed antibodies of the participants to understand how long nasal antibodies lasted, compared with antibodies found in the blood. They also studied the effect of subsequent COVID-19 vaccines on antibodies in the nose and blood.
Samples were taken when people were hospitalised and at six months and one year after. Since most people were vaccinated during the study, many samples were also taken before and after vaccination.
They measured how well the antibodies neutralised the original SARS-CoV-2 virus, and the Delta and Omicron variants to see how long the antibodies were effective for after infection or vaccination.
The study included 446 people admitted to hospital in the early phase of the pandemic, including 141 who provided samples at the start of the study and six and 12 months later. For participants who only had one sample taken during the 12-month period of study, the researchers used modelling to estimate how the average antibody responses changed over time.
Of those who confirmed whether they had been vaccinated (323 people), 95% (307 people) received their first vaccination during the study follow-up period. This led to increases in all nasal and blood antibodies, but the change in the first-line defence nasal antibodies (IgA) was small and temporary. The researchers found that the participants’ sex, disease severity and age did not impact how long their nasal immunity lasted, but caution that their study was only in people with severe disease that required hospitalisation.
They also found that blood antibody from participants continued to bind the original SARS-CoV-2 virus, and the Delta and Omicron variants a year after infection, but found that booster vaccines are needed to maintain this immunity.
Co-senior author of the study, Dr Lance Turtle, Senior Clinical Lecturer at the University of Liverpool and Consultant in Infectious Diseases at Liverpool University Hospitals, said: “Our study suggests that this first-line defence immunity is separate from other immune responses, and although it is increased by vaccination and infection, it only lasts for about nine months. Nonetheless, booster vaccines can increase it slightly and otherwise have a significant impact on other areas of immunity, protecting against severe disease and death very effectively, so remain very important.”
The researchers note that their study did not screen participants for reinfection, but that this was unlikely to have occurred since the study took place during periods of national restrictions and lockdowns when COVID-19 incidence was low and people were not mixing. In a preliminary analysis, they found only two cases of reinfection in their study, suggesting that the overall trends seen are accurate.
The study was supported by the ISARIC4C, UKCIC and PHOSP-COVID consortia. It was jointly funded by the National Institute for Health and Care Research, UK Research and Innovation and the Medical Research Council.
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(Family Features) Many people don’t think much about whether their blood is clotting properly. However, when you have a bleeding disorder, a condition that affects the way your body controls clots, it’s no small matter.
According to the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health, abnormal clotting can lead to a host of problems, including excessive bleeding after an injury or during surgery.
About 3 million people in the U.S. have bleeding disorders. Some types, such as hemophilia, are inherited, meaning a person who has it is born with it. Inherited bleeding disorders are caused by certain genes passed down from parents to children. These genes contain instructions for how to make proteins in the blood called clotting factors, which help blood clot. If there is a problem with one of these genes, such as a mutation – a change in the gene’s instructions – the body may make a clotting factor incorrectly or not make it at all.
You can also have what’s called an acquired bleeding disorder, meaning you develop it during your lifetime. Acquired bleeding disorders can be caused by medical conditions, medicines or something unknown. Your risk of developing a bleeding disorder depends on your age, family history, genes, sex, or other medical conditions. If bleeding disorders run in your family, you may have a higher risk of developing or inheriting one.
Symptoms of a bleeding disorder may appear soon after birth or develop later in life and can include:
Excessive bleeding or bruising, such as frequent or long nose bleeds (longer than 15 minutes) or frequent or long menstrual periods
Petechiae, which are tiny purple, red, or brown spots caused by bleeding under the skin
Redness, swelling, stiffness, or pain from bleeding into muscles or joints
Blood in urine or stool
Excessive umbilical stump bleeding
Excessive bleeding during surgery or after trauma
If you believe you, or someone you care for, may have a bleeding disorder, talk to a health care provider. Your provider may make a diagnosis based on symptoms, risk factors, family history, a physical exam, and diagnostic tests. Health care providers typically screen for bleeding disorders only if you have known risk factors or before certain surgeries.
How your bleeding disorder is treated depends on its type. If your disorder causes few or no symptoms, you may not need treatment. If you have symptoms, you may need daily treatment to prevent bleeding episodes, or you may need it only on certain occasions, such as when you have an accident or before a planned surgery.
If you have been diagnosed with a bleeding disorder, it’s important to be proactive about your health and follow your treatment plan. To lower your risk of complications:
A Story of Bravery, Balance, and a Bleeding Disorder
There are lots of things that make Mikey White Jr. special. He’s a dedicated athlete. He’s determined, disciplined, and optimistic. He’s also living with hemophilia, a type of bleeding disorder.
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White was diagnosed with hemophilia at age 3 after experiencing several severe bleeding episodes. He had to give up baseball and basketball, his passions, because of the high risk of injuries, but he found competitive swimming – and he’s been breaking records ever since.
“Competitive swimming is a noncontact sport, so it complements my hemophilia while still being an intense and rigorous sport,” White said.
Being an athlete with hemophilia requires support, White admits. He works with his healthcare team and coaching staff to make sure he safely manages his condition and balances it with his training. He hopes his story encourages others living with bleeding disorders to accept and appreciate their bodies the way they are.
(Family Features) Most people don’t want to think about death – let alone talk about it. When the time comes, families often find themselves overwhelmed, not only by grief but by the many decisions that need to be made quickly.
Funeral directors witness this every day. They see the stress and confusion that can come when there is no plan in place and the peace of mind that comes with thoughtful preparation.
After consulting funeral directors nationwide, the National Funeral Directors Association (NFDA) uncovered five things they wish families knew before a death occurs.
It’s Never Too Early to Start Planning
While everyone knows death and taxes are inevitable, conversations about death are often avoided.
Simply documenting your wishes and discussing your preferences with your family can alleviate the difficult decisions your loved ones will have to make in the future. Speak with a funeral director to explore the many options for planning a meaningful funeral.
Legal and Financial Details Can Cause Unexpected Issues
Families often don’t realize power of attorney ends at death, meaning a designated person can no longer make decisions or access bank accounts once an individual dies.
To avoid complications, consider adding a trusted loved one to your bank account and ensure life insurance beneficiaries are up to date. Too often, deceased individuals leave minor children, deceased spouses or former partners as beneficiaries, leading to legal and financial challenges.
Final Wishes Shouldn’t Be In Your Will
Many people believe the best place to document their final wishes is in their will. However, wills are often not read until after funeral services take place, making them an unreliable way to communicate last requests. Instead, discuss and document your wishes with family members or a trusted funeral professional who can keep your wishes on file until there is a need.
There Are a Variety of Memorialization Options
End-of-life planning offers more choices than many realize. While burial remains a common preference, cremation is an increasingly popular choice and can even include a viewing and funeral service. Additionally, eco-friendly options, such as alkaline hydrolysis, natural burial and natural organic reduction are becoming more widely available for those seeking green memorialization. In fact, according to NFDA’s 2024 Consumer Awareness and Preferences Study, 68% of respondents expressed interest in green funeral options.
Exploring these possibilities with a funeral professional can help ensure your final arrangements reflect your values, traditions and personal wishes.
Funeral Directors Don’t Just Manage Funerals – They’re Trusted Guides In Honoring Life
Funeral directors play a vital role in helping families create meaningful services that reflect their loved one’s life, values and traditions. Whether planning ahead or facing a recent loss, funeral professionals provide expertise, compassionate care and personalized guidance during one of life’s most difficult moments.
Choosing the right funeral director is an important decision and finding someone who understands your needs can make all the difference in honoring your loved one in a personal and meaningful way.
Start the conversation today by talking about end-of-life planning. It isn’t easy, but it’s one of the most important conversations you can have with your loved ones. A little planning today can make a world of difference tomorrow.
Use comprehensive resources like RememberingALife.com, which is designed to guide families through every stage of the journey, including planning, funeral options and grief resources. The site offers valuable tools and support, such as the “Find a Funeral Home” tool to connect families with compassionate, local funeral directors and much more.
Photo courtesy of Shutterstock
SOURCE:National Funeral Directors Association
Workers who are in frequent contact with potentially sick animals are at high risk of bird flu infection.
Costfoto/NurPhoto via Getty ImagesRon Barrett, Macalester College
Disease forecasts are like weather forecasts: We cannot predict the finer details of a particular outbreak or a particular storm, but we can often identify when these threats are emerging and prepare accordingly.
The viruses that cause avian influenza are potential threats to global health. Recent animal outbreaks from a subtype called H5N1 have been especially troubling to scientists. Although human infections from H5N1 have been relatively rare, there have been a little more than 900 known cases globally since 2003 – nearly 50% of these cases have been fatal – a mortality rate about 20 times higher than that of the 1918 flu pandemic. If the worst of these rare infections ever became common among people, the results could be devastating.
Approaching potential disease threats from an anthropological perspective, my colleagues and I recently published a book called “Emerging Infections: Three Epidemiological Transitions from Prehistory to the Present” to examine the ways human behaviors have shaped the evolution of infectious diseases, beginning with their first major emergence in the Neolithic period and continuing for 10,000 years to the present day.
Viewed from this deep time perspective, it becomes evident that H5N1 is displaying a common pattern of stepwise invasion from animal to human populations. Like many emerging viruses, H5N1 is making incremental evolutionary changes that could allow it to transmit between people. The periods between these evolutionary steps present opportunities to slow this process and possibly avert a global disaster.
Spillover and viral chatter
When a disease-causing pathogen such as a flu virus is already adapted to infect a particular animal species, it may eventually evolve the ability to infect a new species, such as humans, through a process called spillover.
Spillover is a tricky enterprise. To be successful, the pathogen must have the right set of molecular “keys” compatible with the host’s molecular “locks” so it can break in and out of host cells and hijack their replication machinery. Because these locks often vary between species, the pathogen may have to try many different keys before it can infect an entirely new host species. For instance, the keys a virus successfully uses to infect chickens and ducks may not work on cattle and humans. And because new keys can be made only through random mutation, the odds of obtaining all the right ones are very slim.
Given these evolutionary challenges, it is not surprising that pathogens often get stuck partway into the spillover process. A new variant of the pathogen might be transmissible from an animal only to a person who is either more susceptible due to preexisting illness or more likely to be infected because of extended exposure to the pathogen.
Even then, the pathogen might not be able to break out of its human host and transmit to another person. This is the current situation with H5N1. For the past year, there have been many animal outbreaks in a variety of wild and domestic animals, especially among birds and cattle. But there have also been a small number of human cases, most of which have occurred among poultry and dairy workers who worked closely with large numbers of infected animals.
Pathogen transmission can be modeled in three stages. In Stage 1, the pathogen can be transmitted only between nonhuman animals. In stage 2, the pathogen can also be transmitted to humans, but it is not yet adapted for human-to-human transmission. In Stage 3, the pathogen is fully capable of human-to-human transmission.Ron Barrett, CC BY-SA
Epidemiologists call this situation viral chatter: when human infections occur only in small, sporadic outbreaks that appear like the chattering signals of coded radio communications – tiny bursts of unclear information that may add up to a very ominous message. In the case of viral chatter, the message would be a human pandemic.
Sporadic, individual cases of H5N1 among people suggest that human-to-human transmission may likely occur at some point. But even so, no one knows how long or how many steps it would take for this to happen.
Influenza viruses evolve rapidly. This is partly because two or more flu varieties can infect the same host simultaneously, allowing them to reshuffle their genetic material with one another to produce entirely new varieties.
Genetic reshuffling – aka antigenic shift – between a highly pathogenic strain of avian influenza and a strain of human influenza could create a new strain that’s even more infectious among people.Eunsun Yoo/Biomolecules & Therapeutics, CC BY-NC
These reshuffling events are more likely to occur when there is a diverse range of host species. So it is particularly concerning that H5N1 is known to have infected at least 450 different animal species. It may not be long before the viral chatter gives way to larger human epidemics.
Reshaping the trajectory
The good news is that people can take basic measures to slow down the evolution of H5N1 and potentially reduce the lethality of avian influenza should it ever become a common human infection. But governments and businesses will need to act.
People can start by taking better care of food animals. The total weight of the world’s poultry is greater than all wild bird species combined. So it is not surprising that the geography of most H5N1 outbreaks track more closely with large-scale housing and international transfers of live poultry than with the nesting and migration patterns of wild aquatic birds. Reducing these agricultural practices could help curb the evolution and spread of H5N1.
Large-scale commercial transport of domesticated animals is associated with the evolution and spread of new influenza varieties.ben/Flickr, CC BY-SA
People can also take better care of themselves. At the individual level, most people can vaccinate against the common, seasonal influenza viruses that circulate every year. At first glance this practice may not seem connected to the emergence of avian influenza. But in addition to preventing seasonal illness, vaccination against common human varieties of the virus will reduce the odds of it mixing with avian varieties and giving them the traits they need for human-to-human transmission.
At the population level, societies can work together to improve nutrition and sanitation in the world’s poorest populations. History has shown that better nutrition increases overall resistance to new infections, and better sanitation reduces how much and how often people are exposed to new pathogens. And in today’s interconnected world, the disease problems of any society will eventually spread to every society.
For more than 10,000 years, human behaviors have shaped the evolutionary trajectories of infectious diseases. Knowing this, people can reshape these trajectories for the better.Ron Barrett, Professor of Anthropology, Macalester College
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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(Family Features) Most people don’t want to think about death – let alone talk about it. When the time comes, families often find themselves overwhelmed, not only by grief but by the many decisions that need to be made quickly.
Funeral directors witness this every day. They see the stress and confusion that can come when there is no plan in place and the peace of mind that comes with thoughtful preparation.
After consulting funeral directors nationwide, the National Funeral Directors Association (NFDA) uncovered five things they wish families knew before a death occurs.
Ron Barrett, Professor of Anthropology, Macalester College
This article is republished from The Conversation under a Creative Commons license. Read the original article.
