If You’re Worried About Your Child’s Well-Being, Add These Supplements In Their Diet to Boost Their Immunity

As a parent, nothing is more important than your child’s health and well-being. From the time that they’re babies and well after they’ve grown into self-functioning, self-sufficient adults, parents continue to worry about their child’s health.

Consider it a blessing in disguise or light at the end of the tunnel- due to COVID-19, we’ve all been granted a rare opportunity to spend a lot more time with our entire family. Of course, while maintaining social distancing practices. Plus, with the virus outbreak, parents have become even more invested in their child’s health than they were before.

During these times, it is absolutely vital to ensure that your child’s immune system is in perfect shape. To that measure, we’ve taken the liberty of listing some of the best supplements that can help in boosting your child’s immunity, and the best foods you can give them at this time.

1. Vitamin C

Vitamin C? More like the superstar of all the vitamins. It is impossible to overstate the role that this vitamin plays in your child’s well-being. The antioxidant is responsible for many vital functions of the body, including the formation of blood vessels, collagen, and muscle. It is also instrumental in the absorption of iron. Vitamin C is commonly found in berries, citrus fruits, broccoli, and red bell peppers.

2. Zinc

You must have guessed this would be on the list, too. Zinc plays a major role in the development and growth of your child. In fact, it is one of the most vital supplements that your brain needs for its proper growth and development. Zinc also plays an important role in ensuring that your child’s immune system functions properly. The supplement can be found in foods like nuts, legumes, shellfish, seeds, and whole grains.

3. Vitamin D

Also known as the sunshine vitamin due to its biggest source, Vitamin D does magical wonders for your child’s immunity. It helps your child boost their body’s ability to fight off infections. It also ensures that your child can build stronger bones.

So, a little extra playtime under the sun might not be so bad after all. Vitamin D can also be found in certain foods like fish oil or salmon. If your child is unable to get enough Vitamin D through these sources, you can always opt for gummy supplements. Make sure you consult a doctor before doing so.

4. Vitamin A

Vitamin A is absolutely essential for protecting your child’s vision. Apart from that, it also plays a significant role in boosting immunity. It can be foods in many foods, including carrots, sweet potato, cantaloupe, mango, and spinach.

5. Echinacea

If you’re having a hard time pronouncing that, don’t sweat it. Just repeat after us: eh-kuh-nay-shuh. Not so hard anymore, right? If you’re still looking for a simpler word, just go with purple coneflower. This little flower is packed with antioxidants, which will help your child’s body while battling different virals and infections. You can give this to your child in the form of gummies, syrup, or powder.

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Snapshot of COVID-19 vaccine intentions highlights challenges of achieving community immunity goals


Ahead of the first U.S. emergency use authorization for a COVID-19 vaccine, only half of Americans said they were likely to get vaccinated as soon as possible, according to an in-depth study led by researchers at the Johns Hopkins Bloomberg School of Public Health.

The researchers conducted an online survey of 2,525 Americans in a two-week period from late November to early December, asking them about their intentions regarding COVID-19 vaccination as well as other values and beliefs. About 50 percent responded that they intended to get vaccinated as soon as possible. About 10 percent said they intended not to be vaccinated at all. The remaining 40 percent replied that they probably wouldn’t be vaccinated, or probably would be but not as soon as possible.

The findings were published online March 24 in the journal Vaccine.

The authors labeled these groups “intenders” (as soon as possible), “unlikelys” (not at all), and “wait and learn” (maybe not, definitely not as soon as possible). While the numbers may have shifted somewhat as vaccinations rolled out across the U.S. this winter, the authors say outreach should focus on the “wait-and-learn” group, people who expressed an inclination to possibly or eventually get the vaccine, even if it wasn’t as soon as possible.

“Once we get the first 50 percent vaccinated, we’re going to be left with as many as 40 percent that are unsure, so we need to start working with them now,” says study lead author Daniel Salmon, Ph.D., a professor in the Department of International Health and director of the Institute for Vaccine Safety at the Bloomberg School. “With these survey results, we now understand that critical 40-percent group much better.”

Understanding attitudes around vaccines is essential for achieving community or herd immunity which, when enough people have been vaccinated, greatly reduces and controls community transmission and protects even the unvaccinated. Without vaccinating children younger than 16, achieving community immunity for SARS-CoV-2—the virus that causes COVID-19—will require that up to 90 percent of adults get highly effective vaccines. The researchers note that widespread hesitancy about COVID-19 vaccination appears to be a major obstacle to this goal.

Compared to the intenders, those who planned on getting vaccinated as soon as they could, the wait-and-learn group was overall more likely to have lower levels of trust in local, state, and federal public health authorities and health care professionals, along with less confidence in vaccine safety. The wait-and-learn respondents were more likely, for example, to be concerned that governments and drug companies used people “like them” to conduct experiments. “Like them” was intentionally undefined in the survey and could have been interpreted to be age, race, or ethnicity, or a medical condition. They also reported they were more likely to know someone who had a serious reaction to a vaccine.

The survey included 2,525 people, and oversampled African Americans and Hispanics to increase the statistical power of analyses concerning these groups. The results were adjusted to weight different demographic groups according to their true proportions in the U.S. population.

More than half—52 percent—of Black respondents were in the wait-and-learn group, reporting they may not get the vaccine or delay getting it. In comparison, 35 percent of white respondents and 39 percent of Hispanic respondents were in the wait-and-learn group. The data suggest that historical injustices and present-day racism against Black people may be factors in vaccine hesitancy. For example, three quarters of Black respondents in the wait-and-learn group are concerned that the government and drug companies experiment on people like them, compared to just over half of white respondents (54 percent) and two-thirds (69 percent) of Hispanic respondents. Thirty-nine percent of Black respondents in this group were confident that vaccines are safe, compared to over half of white (55 percent) and Hispanic (52 percent) respondents.

Salmon and colleagues conducted the survey in English and Spanish between November 25 and December 7 of last year, using Ipsos KnowledgePanel, a panel of thousands of people in United States households who stand ready to take part in polls and surveys. During this survey period, the first successful phase 3 clinical trial results for COVID-19 vaccines had already been announced, but the Food and Drug Administration had not yet approved any of them for emergency use.

“Everything about the ‘wait-and-learn’ group suggests that there will continue to be challenges,” Salmon says. “A near-term approach we see is for public health to work with community leaders to connect with people with low levels of trust in government. COVID-19 vaccines afford the opportunity to work with local communities to build trust and reduce inequities.”

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Europe can achieve herd immunity by July: EU commissioner


Europe could have herd immunity against COVID-19 by July, a European Union commissioner has said, as incoming jabs are expected to speed up the continent’s sluggish vaccine rollout.

The note of optimism comes even as several European countries have started reimposing restrictions as they contend with surging coronavirus infections, and after mixed messaging on the safety of a key jab.

“Let’s take a symbolic date: by July 14, we have the possibility of achieving immunity across the continent,” Thierry Breton, the EU’s commissioner for the internal market told French broadcaster TF1.

“We’re in the home stretch, because we know that to beat this pandemic there’s just one solution: vaccination. The vaccines are arriving,” he said.

More than a third of France’s population is now under renewed lockdown, while frustrations over virus curbs spilled into weekend demonstrations in Germany, Amsterdam, Bulgaria and Switzerland.

Europe’s battle to prevent a deadly third wave of infections has been complicated by a patchy vaccine drive that included several nations temporarily halting AstraZeneca’s shots in response to isolated cases of blood clots.

Most have since resumed using the vaccine after the European Medicines Agency found it “safe and effective”.

But AstraZeneca has delivered only 30 percent of the 90 million doses it promised the EU for the first quarter.

Breton said he was confident more vaccines will arrive soon, with 300-350 million doses expected between March and June.

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How immunity boosting experiment saved couch potato when he got Covid

A couch potato took part in a TV experiment on boosting immunity – and when he got Covid, it saved him

  • The Truth About Boosting Your Immune System, airs on the BBC on Wednesday
  • Six volunteers will undergo a crash course to turn around their immune systems
  • Exercise-phobic David Richard came down with Covid during the experiment
  • But his symptoms were mild after he took part in the strict exercise regime

It is a perennial health question that has never seemed more relevant: just how can we boost our immune system and give ourselves the best fighting chance against infection?

Thousands of books, articles and blogs have been written on the subject (unsurprisingly, more than ever in the past 12 months), making audacious claims about specific regimes, diets and superfoods, which, they claim, will stave off illness and help us recover faster if we do succumb.

Meanwhile, chemist and supermarket shelves heave with products aimed at ‘supporting the immune system’ and other sufficiently vague yet intriguing promises. The problem is, there’s barely a jot of evidence for any of it.

Now, a timely BBC documentary has put some of the best-known immune-boosting theories to the test and found that, in just six weeks, a few simple lifestyle changes can make a significant difference, giving our body the tools it needs to defeat the common cold and flu. And, yes, perhaps even Covid.

The Truth About… Boosting Your Immune System, which airs on Wednesday, features six volunteers who undergo a six-week crash course designed to turn around their underperforming immune systems.

David Richards is one of the participants in the BBC’s experimental documentary, The Truth About Boosting Your Immune System

Each was picked as they’d admitted to having unhealthy lifestyles, such as boozing, eating too much junk food and doing little or no exercise – and suffering regular coughs and colds.

Blood tests at the start of the experiment confirmed that their immune systems were not functioning as well as they could be. Their new regime was nothing too unusual: a varied, balanced diet, high in fibre (yes, lots of fruit and veg), regular exercise and a good sleep pattern.

At the end of the programme, the participants not only felt better, but further blood tests proved their disease-fighting immune responses had become stronger.

Immunologist Professor Sheena Cruickshank, at the University of Manchester, helped oversee the experiment. She says: ‘The rapid response seen was pretty surprising. Their blood tests revealed the plan led to an increase in cells that produce disease-fighting antibodies.’

The programme also reveals other, perhaps less obvious ways to help boost immunity, from massages to cold showers, which have immediate benefits.

Our immune system is just that – a network of organs, glands, cells and compounds throughout the body, which protect us from attack by viruses, bacteria, parasites and other pathogens. As we age, levels of some immune-system cells naturally wane, which is why we tend to become more vulnerable to infections of all kinds.

But age isn’t the only factor – lifestyle plays a big part too. Alcohol, for instance, seems to have a wholly negative impact, even in relatively small amounts. Clinicians have long known that heavy drinking in the long term is associated with a raised risk of immune-related illness, such a pneumonia, slow recovery from illness and poor healing of wounds. 

But, in fact, the effects can be near-instantaneous. When it enters the gut, alcohol alters the make-up of our gut microbiome – the trillions of microorganisms that live in our gut which play an important role in immunity.

This, in turn, damages immune cells in the blood, including our lymphocytes, which are responsible for sending out antibodies.

Antibodies play a vital role in immunity, attacking and destroying invaders such as viruses.

In an experiment, with blood samples taken before and after drinking, presenter Dr Ronx Ikharia, an emergency medicine specialist, downs three glasses of prosecco and finds it is enough to bring down levels of lymphocyte cells by as much as 50 per cent. 

This could reduce the effectiveness of the body’s immune response – and for this reason Prof Cruickshank says people should avoid alcohol around the time of having the Covid jab.

David Lloyd, 38, pictured doing a dance routine with his daughter for exercise, also took part in the experiment

‘You need to have your immune system working tip-top to have a good response to the vaccine, so if you’re drinking the night before, or shortly afterwards, that’s not going to help.’

Alcohol isn’t the only vice that can impact the body’s immune response either. As the volunteers, all recruited from Crewe, find out, their choices in food and exercise are a major factors too.

Salesman David Lloyd, 38, admits he could be taking better care of his body. ‘I like a bit of McDonald’s, KFC, you know, fast food,’ he says. When asked whether he would class his approach to exercise as relaxed, moderate or vigorous, David quips: ‘What’s exercise?’

Meanwhile, Ruth Minshull, 47, a personal assistant, says her lifestyle has become increasingly sedentary. She says: ‘My diet has got worse, and I wouldn’t even say I do a little exercise these days. I do no exercise, truthfully.’

And couch potato Nadiya Remtulla, 45, a car-leasing manager, suffers from constant colds.

At the start of the six-week experiment, blood samples are taken from the volunteers and measured for the number of two key sets of immune cells – neutrophils and lymphocytes. 

Neutrophils are fast-responding immune cells that attack pathogens that can cause diseases as soon as they enter the body, while lymphocytes help the immune system ‘learn’ about different types of foreign invaders, and send out antibodies to fight them off.

If the levels of neutrophils in the blood are too high, it suggests that the body’s immune system is over-active – sending out cells to fight infection when it is not there. Low levels of lymphocytes suggest that the body’s ability to defend itself is impaired. In five out of six of the volunteers, test showed neutrophil levels were high, while lymphocyte levels were low.

According to Prof Cruickshank, the consequences could become serious. ‘Over time, if the immune system is out of balance, you’ll start to feel more run down. You’ll become more susceptible to infection, such as colds, and infections will stay longer.’ Prof Cruickshank warns: ‘These people could suffer more severe Covid illness.’

The good news is that it’s reversible. Prof Cruickshank’s first step for the participants is to change what they eat. Their new diet is one that aims to build ‘gut diversity’ – the variety within the make-up of the organisms that live in the gut and form part of the immune system. Studies show a diet high in meat, saturated fats and sugar can, as alcohol does, create imbalances in the kinds of bacteria in the gut.

And, as with alcohol, this can lead to weakened or abnormally behaving immune system cells in the blood. Meanwhile, diets rich in fibre – vegetables, wholegrains, beans, pulses such as lentils and cereals – can support good gut diversity, promote the development of antibody-producing lymphocytes, and help balance immune cells in the blood.

To illustrate, an analysis of salesman David Lloyd’s gut bacteria, using a stool test, revealed a shockingly low level of diversity.

Immunologist Professor Sheena Cruickshank, at the University of Manchester, helped oversee the experiment

‘All the participants ate very low-fibre diets, with few fruit or veg,’ says Prof Cruickshank.

‘We put them on a fibre-rich diet, not necessarily designed to make them lose weight, but to expose them to a wider group of foods.’

The volunteers replaced high-sugar snacks such as biscuits and chocolate bars with nuts, and had large helpings of vegetables with all their meals.

Personal assistant Ruth admits her meals often consist mainly of cheese and bread, so, like many of the volunteers, she found the new regime ‘a big change’. But they all found something to enjoy. Biscuit fan Nadiya now loves eating figs.

The volunteers were also given fitness trackers and asked to do either 75 minutes of vigorous exercise or 150 minutes of moderate exercise each week.

Scientists believe that exercise boosts our immune system because it helps regulate the flow of immune cells around the body. As our blood flow increases with the heart rate, immune cells move more rapidly into our veins and are able to roam the body at the higher rate and in higher numbers.

A British study in 2011 found that people who did aerobic exercises five or more days a week were 40 per cent less likely to have a cold, over three months, than those who did one day of exercise a week.

‘Exercise is absolutely brilliant for your immune system,’ says Prof Cruickshank. ‘A good bit of moderate exercise really helps stimulate your immune system to help it work optimally.’

On top of that, the volunteers were instructed to stick to a good sleep schedule – with at least eight hours a night suggested. While asleep, humans produce more lymphocytes than they do while awake. This is because hormones such as adrenaline, which keep us alert, inhibit lymphocyte production. When we are asleep we produce less of these hormones.

One study which followed a group of volunteers for two weeks found those who slept less than seven hours a night were almost three times more likely to develop a cold than those who get more than eight.

While diet, exercise and sleep are the most important areas to focus on to help your body fight off infection, there are other ways to boost your immune system.

In the programme, Dr Ronx learns that stress, in the short term at least, can help bolster our defences. Long-term stress is generally considered harmful – for the same reason a lack of sleep damages the immune system. Stress hormones impact the body’s ability to produce lymphocytes. But, a short, sharp dose of stress has its benefits.

Massages and cold showers can boost your immunity, but you should go teetotal the week of your jab, according to experts

When we perceive danger, it triggers the release of a cascade of hormones and other compounds in the body that make us more alert and ready for physical action.

It also stimulates the production of neutrophils and other basic fighter cells – an evolutionary explanation is that, should we be wounded, which opens the body to potential infection, it would help better protect us.

DURING another experiment, arachnophobe Dr Ronx is asked to hold a tarantula, and blood tests are taken before and after to see if there is a difference in the levels of immune cells. The results are conclusive. There is a ten per cent increase in Dr Ronx’s white blood cells following that frightening experience.

This sort of change would effectively make the body better at fighting off an infection – for a few hours at least. Despite this, few will be prepared to scare themselves silly in a bid to avoid getting the odd cold, or even Covid. But research shows the ‘fright’ doesn’t need to be quite so extreme to be effective.

A Netherlands study found that, over a period of a year, people who had a normal shower and then for the final 30 seconds switched it to cold, were 30 per cent less likely to have sick days from work. Scientists believe this is linked to the body’s stress response.

Dr Ronx also finds out there are relaxing ways to boost the immune system too. In studies of people with HIV – a virus that attacks the immune system – massage appeared to increase the number of lymphocyte cells in patients’ blood. Scientists theorise this is because massage stimulates nerves in the skin that connect to glands which produce certain types of lymphocytes. Through stimulation, these glands release lots of lymphocytes into the blood.

Once again, Dr Ronx puts this to the test, undergoing an intense hour-long massage. It turns out Ronx is a ‘super responder’, with 20 per cent increase in lymphocytes in the blood. Dr Ronx adds: ‘Next time you ask your partner for a foot rub, tell them you’re not being self-indulgent – you’re simply trying to improve your immune system.’

Six weeks after beginning their immune-boosting regime, the volunteers get their results, and for one of them the programme may have had a more dramatic consequence than first intended.

Exercise-phobic David Richard, 48, came down with Covid during the experiment.

Asthmatic and overweight, David was sure that his symptoms would be serious: ‘I’m aware of people my age, who are fitter than me, who have ended up in hospital on the oxygen.’

But, to his surprise, David’s symptoms were mild. He had committed to 150 minutes of moderate exercise a week – including (virtual) dance classes, and brisk walking. And though Dr Ronx and Prof Cruickshank were unable to run a blood test on David because of Covid, he’s sure the regime helped make the difference. ‘I’m convinced that what I’ve done helped me fight this off.’

The rest of the volunteers underwent a lood test to take another look at their neutrophil and lymphocyte levels and the results were staggering. In all but one of them, there was a drop in neutrophils to more normal levels, and a rise in antibody-producing lymphocytes.

And the participant who had no change suffered a cold during the experience, which Prof Cruickshank believes is the reason: ‘A cold can leave your immune cells out of kilter, temporarily. But that’s the immune system doing what it’s designed to do.’

She adds: ‘It was amazing to see these changes in just six weeks.

‘The group adapted well to living healthier lifestyles and their bodies will thank them for it, if they stick to it. Many of them lost weight along the way, too. People take for granted the value of the immune system. The human body is a collection of cells that needs caring for, and the activities we do on a daily basis make a difference.’

  • The Truth About… Boosting Your Immune System is on BBC1 on Wednesday at 9pm

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Medical oddity ushers in discovery of unheard-of ‘immunity gene’ mutations—and a better way to screen them

An infant’s odd case of rare encephalitis not typically found in children led researchers to discover never before seen genetic mutations and a more accurate technique to examine the IRAK4 gene responsible for innate immunity.

The IRAK4 gene instructs the production of a protein that plays a key role in the early recognition and response to invading pathogens. Inherited mutations in this gene can cause an immune system disorder that leaves the body susceptible to recurrent infections of pus-forming pyogenic bacteria. Cases of IRAK4 deficiency are quite rare and only about 10 familial instances were identified so far in Japan.

A Hiroshima University-led research team detected two novel IRAK4 mutations, c.29_30delAT (p.Y10Cfs*9) and c.35G>C (p.R12P), in a 10-month-old boy with anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis and human herpesvirus 6 (HHV6) reactivation. The p.Y10Cfs*9 and p.R12P variations were inherited from his father and mother, respectively. The research team found the mutations by using whole exome sequencing (WES), a method used to exhaustively examine the DNA for genetic disorders.

Anti-NMDAR encephalitis, an inflammation of the brain, happens when the immune system attacks a vital brain receptor, causing psychiatric symptoms, involuntary movement, seizures, autonomic dysfunction, and central hypoventilation. It typically occurs in adult females suffering from ovarian tumor. Only a few cases of anti-NMDAR encephalitis have been so far reported in infants.

The researchers suspect that reactivation of HHV6 may have induced brain damage that triggered the production of anti-NMDAR antibodies.

“It is well known that anti-NMDAR encephalitis is triggered by HSV1 (herpes simplex virus) infection. The post-infectious autoimmune process that follows the HSV-induced brain damage is thought to be the cause of anti-NMDAR encephalitis,” the researchers said in their study published in the Journal of Clinical Immunology.

“The coexistence of anti-NMDAR encephalitis and HHV6 reactivation in this patient may reveal an unknown manifestation associated with IRAK4 deficiency,” they said.

More precise method to analyze IRAK4 mutations

Although the researchers have yet to find direct evidence demonstrating a relationship between IRAK4 deficiency and the development of anti-NMDAR encephalitis or HHV6 reactivation, they were able to establish that mutations p.Y10Cfs*9 and p.R12P are damaging.

The researchers developed a novel NF-κB reporter assay that can precisely evaluate whether an IRAK4 mutation is harmful. The reporter assay allows them to investigate the activation of transcription factor NF-κB which regulates the body’s inflammatory responses.

“Using this system, we confirmed that both novel mutations are deleterious. The current case revealed the possibility that genetics can contribute to characterizing infantile cases with anti-NMDAR encephalitis,” study author Satoshi Okada, a professor at HU’s Graduate School of Biomedical and Health Sciences, said.

They resolved potential issues of misevaluation in a previously developed NF-κB reporter assay by using CRISPR gene-editing technology to remove the IRAK4 naturally expressed in the HEK293 cell—commonly used in studying gene function as it is much easier to transfect than other cell lines.

“HEK293 cells have endogenous IRAK4 expression. Their endogenous IRAK4 prevents the precise evaluation of the activity of introduced WT or mutant IRAK4,” Okada explained.

To date, there are so far 24 known mutations identified in patients with IRAK4 deficiency.

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Could COVID-19 immunity last decades? Here’s the science.

The body builds a protective fleet of immune cells when infected with COVID-19, and in many people, those defenses linger for more than six months after the infection clears, according to a new study.

The immune cells appear so stable, in fact, that immunity to the virus may last at least several years, the study authors said. “That amount of [immune] memory would likely prevent the vast majority of people from getting hospitalized disease, severe disease, for many years,” co-author Shane Crotty, a virologist at the La Jolla Institute of Immunology in California, told The New York Times, which first reported on the study.

That said, making predictions about how long immunity to the coronavirus lasts can be “tricky,” Nicolas Vabret, an assistant professor of medicine at the Mount Sinai Icahn School of Medicine, who was not involved in the study, told Live Science.

“It would be surprising to see the … immune cells build up in patients over six months and suddenly crash after one year,” Vabret said in an email. But “the only way to know whether SARS-CoV-2 immunity will last decades is to study the patients over the same period of time.” 

In other words, we won’t know exactly how long immunity lasts without continuing to study those who have recovered from COVID-19. However, the new study, posted Nov. 16 to the preprint database bioRxiv, does provide strong hints that the protection is long-lived — although clearly not in all people, as there have been several cases of individuals being reinfected with the coronavirus after recovering. 

The research dives into the ranks of the human immune system, assessing how different lines of defense change after a COVID-19 infection. 

These defenses include antibodies, which bind to the virus and either summon immune cells to destroy the bug or neutralize it themselves. Memory B cells, a kind of white blood cell, “remember” the virus after an infection clears and help quickly raise the body’s defenses, should the body be reexposed. Memory T cells, another kind of white blood cell, also learn to recognize the coronavirus and dispose of infected cells. Specifically, the authors looked at T cells called CD8+ and CD4+ cells.

The authors assessed all these immune cells and antibodies in 185 people who had recovered from COVID-19. A small number of participants never developed symptoms of the illness, but most experienced mild infections that did not require hospitalization. And 7% of the participants were hospitalized for severe disease. 

The majority of participants provided one blood sample, sometime between six days and eight months after the onset of their infections. Thirty-eight participants gave several blood samples between those time points, allowing the authors to track their immune response through time.

Ultimately, “one could argue that what they found is not so surprising, as the immune response dynamics they measure look like what you would expect from functioning immune systems,” Vabret said. 

The authors found that antibodies specific to the spike protein — a structure on the surface of the virus — remain stable for months and begin to wane about six to eight months after infection. At five months post-infection, nearly all the participants still carried antibodies. The volume of these antibodies differed widely between people, though, with an up to 200-fold difference between individuals. Antibody counts normally fall after an acute infection, Vabret noted, so the modest drop-off at six to eight months came as no surprise.

By comparison, memory T and B cells that recognize the virus appear extremely stable, the authors noted. “Essentially no decay of … memory B cells was observed between days 50 and 240,” or eight months later, Marc Jenkins, an immunologist at the University of Minnesota Medical School, who was not involved in the study, said in an email.

“Although some decay of memory T cells was observed, the decay was very slow and may flatten out at some point,” Jenkins added. There’s reason to believe that the number of memory T cells may stabilize sometime after infection, because T cells against a related coronavirus, SARS-CoV, have been found in recovered patients up to 17 years later, according to a study published July 15 in the journal Nature

Early in the pandemic, scientists raised concerns that immunity to the virus may wear off in about a year; this trend can be seen with the four coronaviruses that cause the common cold, Live Science previously reported. However, studies suggest that the body’s reaction to common coronaviruses may differ from that to viruses like SAR-CoV and SARS-CoV-2, which hopped from animals to humans. 

“We don’t really know why seasonal coronaviruses do not induce lasting protective immunity,” Vabret said. But the new study, along with other recent evidence, suggests that SARS-CoV-2 immunity may be more robust, said Jason Cyster, a professor of microbiology and immunology at the University of California, San Francisco, who was not involved in the study.

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That said, a few participants in the new study did not mount long-lasting immune responses to the novel virus. Their transient responses may come down to differences in how much virus they were initially exposed to, or genetics may explain the difference, Cyster said. For instance, genes known as human leukocyte antigen (HLA) genes differ widely between individuals and help alert the immune system to foreign invaders, Live Science previously reported

These inherent differences between people may help explain cases of COVID-19 reinfection, which have been relatively rare but are increasing in number, Science Magazine reported.

Again, to really understand how long COVID-19 immunity lasts, scientists need to continue to study recovered patients. “Certainly, we need to look six months down the road,” and see whether the T and B cell counts remain high, Cyster said.

Should immunity be long-term, one big question is whether that durability carries over to vaccines. But natural immunity and vaccine-generated immunity cannot be directly compared, Vabret noted. 

“The mechanisms by which vaccines induce immunity are not necessarily the same as the ones resulting from natural infection,” Vabret said. “So the immune protection resulting from a vaccine could last longer or shorter than the one resulting from natural infection.”

For example, the Pfizer and Moderna vaccines use a molecular messenger called mRNA to train the body to recognize and attack the coronavirus. No mRNA-based vaccine has ever been approved before, so “we practically know nothing about the durability of those responses,” Cyster said.

“I think [that’s] the big unknown for me, among the many,” he said.

But while some unanswered questions remain, the main takeaway from the new study is that “immune memory to SARS-CoV-2 is very stable,” Jenkins said. And — fingers crossed — perhaps those hopeful results will hold well into the future.

Originally published on Live Science. 

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Heterogeneous populations develop herd immunity quicker

In rapidly spreading epidemics such as the current coronavirus pandemic, it is usually expected that a majority of the population will be infected before herd immunity is achieved and the epidemic abates. The estimate of when the threshold for this is reached is usually based on models that assume all individuals in a population are identical. Researchers at the Max Planck Institute for the Physics of Complex Systems in Dresden have used a new model to demonstrate that herd immunity can be achieved at a lower threshold if some individuals are more easily infected than others.

Most epidemics abate before the majority of the population becomes infected. What exactly determines this turning point, and the extent of the epidemic, is not yet well understood. Many epidemic models are based on the assumption that individuals in a population are essentially identical. However, in an actual population, every person is different. For example, some people are less likely to become infected through contact with an infected individual, perhaps due to a more effective immune system, or better hygiene.

A team led by Frank Jülicher from the Max Planck Institute for the Physics of Complex Systems has been investigating the influence of this heterogeneity on the spread of an epidemic. When individuals differ in their susceptibility to an infection, it is primarily the most susceptible who become infected first. This leads to a rapid increase in infection numbers at the beginning of an epidemic. However, this highly susceptible portion of the population soon becomes immune or dies. Therefore, in the uninfected population, the average susceptibility to the virus decreases. This slows the infection rate of the epidemic, and thus the threshold for herd immunity can be lower than previously assumed. A heterogeneous population can thus achieve herd immunity even when only a minority of people are immune. In contrast, in a homogeneous population, herd immunity can only be achieved once a majority is immune.

Different scenarios

According to the Dresden researchers’ model, different scenarios can yield what appears to be the same epidemic course. Specifically, two epidemics, which have different levels of heterogeneities and effectiveness of mitigation measures, can have the same reported time course of infection. In a homogeneous population, immunity only plays a significant role in impacting infection rates when a considerable fraction of the population has been immunized. An early decline in infection rates could therefore only be explained by other factors such as containment measures. In contrast, for a highly heterogeneous population, significant reductions in infections can occur when even a small fraction of the population has been immunized.

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