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Anxiety, Stress, Worry, and Your Body

Stress gets a bad rap for good reason. It can cause physical problems like skin rashes and high blood pressure. It can lead to mental health problems too, like anxiety and depression. But we feel stress for a reason, and sometimes it is good for you.

The stress you feel before a big test or job interview can motivate you to succeed. It can even save your life; stress from a dangerous situation can provoke a fight-or-flight reaction that raises your adrenaline and motivates you to act quickly. Sometimes stress gives you the quick pulse and alert mind you need to stay out of danger.

Whether stress helps or harms your body depends on many factors. One is whether your stress is acute or chronic. You know acute stress when you feel it–the way your heart races right after a car crash, or the sudden jolt of energy you get when you see a snake or spider. Acute stress goes away soon after the stressful cause is gone. But chronic stress is another story. The muscle pain that sets in after months of demanding work, the constant nausea you may feel during a financial crisis, and the uncontrolled weight gain you experience during a long, unhappy relationship can all be signs of chronic stress.

Stress Vs. Anxiety

Stress and anxiety may be related, but they aren't the same thing.

Are you stressed out or anxious? Though we tend to use the words interchangeably, stress and anxiety refer to two different things. Understanding the difference can help you manage both.

Stress

Stress refers to any thought, situation, or event that provokes anger, nervousness, or frustration. Different things stress different people out. For some it could be a traumatic breakup. For others it could be a poor job performance. Still others may feel stress when something reminds them of a trauma.

Anxiety

Anxiety is often provoked by stress, but they’re not the same thing. Anxiety is the uneasiness, fear, or worry you sometimes feel. Stress can bring on anxiety, but anxiety sometimes has no clear cause. Chronic anxiety can lead to several psychological disorders, including:

  • Phobias (like claustrophobia, a fear of tight spaces)
  • Panic disorder (sudden, recurring panic attacks)
  • Generalized anxiety disorder (uncontrolled worry)

Stress and Your Nervous System

Stress starts as a signal in your brain.

When it comes to stress, everything begins in your brain. When you are confronted with danger, like nearly being hit by a car, your brain sends a distress signal to a part of the brain called the hypothalamus. This is where your brain calls the shots for your automatic functions, sending orders to the rest of your body. When you’re stressed, adrenaline signals your body to rev up its heartbeat, blood pressure, and breathing. Your senses become sharper, and your brain becomes more alert.

This all happens in an instant. But stress causes long-term effects too. A hormone called cortisol is released, which keeps your body on high alert until the threat passes. For some situations and some people, though, stress levels remain high even after a perceived threat is gone. This leads to chronic stress.

Cortisol and Weight Gain

If you're stressed out all the time, it can cause you to gain weight.

Chronic stress can add pounds as well as worries. The chemical cortisol acts like a foot on the gas pedal of stress. It is also responsible for some of the physical changes stress can bring on, and some of these are unwanted, especially when stress lingers for weeks or months.

Cortisol puts a high demand on your body’s resources. You need this in the face of danger. But in the modern world stress is more likely to be caused by money problems than dangerous animals. This causes problems that can lead to unwelcome weight gain.

Since cortisol taxes your body’s energy stores, it also makes you hungry–especially for sugary and fatty foods that give you a quick burst of energy. If your stress isn’t prompting physical exercise in response, you’re likely to gain weight. What’s more, cortisol encourages your body to store excess energy as fat.

How much cortisol causes weight gain likely varies from person to person. Tests on sheep show that some are more responsive to cortisol than others. These high-cortisol responders eat more than other sheep when stressed and also gain more weight. Some researchers think this could help identify people who are prone to stress-related obesity.

Stress and Your Muscles

Muscle tension can make exercise difficult, and stress causes muscles to tense up.

Stress makes you tense up. That’s good if you’re facing down an angry predator. But if it persists, muscle tension causes several problems. Tension headaches and migraines can result, for instance. Tense muscles can provoke more serious anxiety disorders, too.

How you respond to stress could help determine how swiftly you recover from injury as well. If you become excessively fearful of reinjuring yourself, this can leave you in a state of chronic pain. Your muscles will seldom relax if you continue to feel fearful. This persistent tension can also lead to muscle atrophy, as it is difficult to move when you are intensely bound up by your own muscles. This is a problem that can get worse, as exercise is one of the most reliable means of relieving stress.

Taking a Breath

If you have asthma or lung disease, stress might make things worse.

Constant worry affects your breathing. People under a lot of stress tend to take deeper breaths and to breathe more often than calm people. This is your body’s way of shoring up the oxygen it needs to respond to a physical stressor. That’s usually fine, but not always. If you have breathing problems like asthma or lung disease, all this breathing can make your problems worse.

How Stress Affects Your Heart

Can stress cause heart attacks? Research says yes.

When your stress is sudden and lasts for a limited time (acute stress), your heart starts pumping faster right away. It’s part of the way your body adjusts to dangerous situations. That isn’t especially hard on your body. But what if your “stress” lever gets stuck and you wind up with ongoing chronic stress?

Chronic stress keeps your heart rate up for long expanses of time. It also causes your blood pressure to increase. These put you at greater risk of major heart disorders such as heart attack and stroke.

The health problems stress brings to your heart don’t end there. Repeated episodes of acute stress or ongoing chronic stress could increase the inflammation in your circulatory system, especially inside your coronary arteries. This could explain how intense stress can bring on heart attacks. In addition, stress may raise cholesterol levels in some people, which affects the circulation and heart as well.

Stress and Diabetes

Being stressed out can be dangerous for people with type 2 diabetes.

Stress carries special risks for those vulnerable to type 2 diabetes. When stress causes your body to release cortisol and epinephrine, these chemicals send a message to your liver. The liver is told to produce more glucose, the sugar that fuels your body for its fight-or-flight response.

For most people, added glucose can be reabsorbed without trouble. But for someone with type 2 diabetes–whether diagnosed or undiagnosed–this can lead to dangerous consequences. This condition causes extra glucose to back up into the bloodstream, causing a variety of problems like blurry vision, extreme fatigue, and infections. Type 2 diabetes is more common for people who are overweight, who are over age 40, or who belong to African, Hispanic, Asian, Pacific Island, and indigenous American ethnicities.

Fighting Off Colds While Stressed

Stress can make fighting a cold easier or tougher depending on what kind of stress you have.

Does stress make it harder to fight off infections? Colds, flus, and other communicable diseases may be fought off more easily if you experience certain kinds of stress. But other forms of stress can make it harder to beat that cold.

Mild, acute stress seems to prepare your body to fight off infections. Studies on lab rats show that as their stress hormones rise, the animals release immune cells to the blood and skin. These are crucial places for immune cells to ward off diseases.

However, if your stress is chronic, lasting for weeks or months, the opposite seems to be true. Chronic stress inhibits some of the body’s most important infection-fighters: T-cells. As a result, someone suffering from chronic stress is left vulnerable to infectious diseases.

Stress and Your Stomach

Vomiting and nausea can be brought on by worry.

Stress affects your digestive system in several ways. Almost everyone has felt “butterflies” in their stomach at the approach of a big test or an important meeting. If you experience more intense stress, though, those butterflies can transform into nausea or even vomiting. Very intense physiological stress, like the kind seen in cases of serious illness, can also cause stomach ulcers.

The stomach isn’t the only place along your digestive tract harmed by stress. Stress can also lead you to eat more and to eat poorly. This can cause heartburn, especially if you eat more fatty foods than normal, as well as acid reflux. These conditions are mostly felt inside your esophagus, which is more sensitive than your stomach. Stress can make the pain from these conditions worse as well.

Stress and Bathroom Habits

Constipation and diarrhea are two potential symptoms of chronic stress.

Stress can change the way your intestines absorb nutrients, and how quickly food moves through your body. In this way stress can lead to either constipation or diarrhea. It doesn’t help that stress provokes you to eat more greasy and sugary foods, often in the form of processed foods. These foods can make your gut leaky, causing additional problems like inflammation.

Chronic stress can change the bacteria in your digestive system as well. Bad bacteria begin to replace the good bacteria, which can be killed off. With different bacteria available, the foods you eat begin to digest differently. One study showed that women with irritable bowel syndrome (IBS) experience worse digestive symptoms when stressed out, and that their stress is strongly associated with anxiety and depression.

The best ways to ward off these problems include exercising and maintaining a healthy diet (especially one containing fiber. However, until you get a handle on your stress, these problems are likely to continue.

How Stress Affects Men

Men and women tend to experience stress differently.

Studies show that stress tends to affect men and women differently. Men are more prone than women to “mental stress,” specifically regarding work. Men dealing with chronic stress are less likely than women to take care of their symptoms. They’re less likely to lean on friends and family for help, and are less likely to prioritize quality sleep. Clearly men could learn a thing or two from women in this regard.

Hormones may be at play. While men and women release stress hormones in similar ways, there’s a big difference in how oxytocin is released in response. Oxytocin promotes nurturing feelings and feelings of well-being. And women receive it in much higher doses when stressed than men do. Oxytocin may encourage women to look for help from others by nurturing and befriending, whereas men are more likely to flee from their stress or lash out in response to it.

Men, Stress, and Sexual Health

Stressed-out men can bring their worried minds into the bedroom, where it causes problems. Men with chronic stress can build up too much cortisol, which can lead to a variety of sexual health problems, such as:

  • Lower testosterone
  • Lower sperm count
  • Erectile dysfunction
  • Lack of arousal
  • Premature ejaculation, and
  • Infections of the testes, urethra, and prostate.

How Stress Affects Women

Stress can make PMS worse.

Women are stressed out in different ways, and from different causes, than men. While men are most likely to report that work causes stress, women are more likely to attribute their stress to financial worries. They’re also far more likely to report high levels of stress than men. In one survey, 28% of women said they experience stress at a level of eight to 10 on a 10-point scale, with only 20% of men reporting the same.

Women also handle their stress differently than men. Perhaps it’s oxytocin as mentioned previously, which women get in higher doses in reaction to stress. Women are more likely to confide in friends and family and to talk about their emotions more freely. That’s a good thing, as one way to cope with stress is to openly address it.

What’s not so good for women, though, is that their stress is more likely to manifest in physical symptoms. Women are significantly more likely to report stress headaches, stomach complaints, and crying provoked by stress than men.

Stress and Sexual Health in Women

Intense stress can cause women and adolescent girls to miss their periods, or to experience irregular cycles. It can also make their periods more painful. PMS symptoms such as bloating, cramping, and mood swings can worsen, too. Sexual desire can wane for stressed out women as well.

For women approaching menopause, hormonal changes can bring on stress. Emotional stress can make the symptoms of menopause worse, too, such as an increase in the frequency and intensity of hot flashes.

Coping With Stress

Therapy, exercise, and diet can help treat chronic stress.

Chronic stress takes its toll on a huge number of people. One survey found that more than 40% of American adults lose sleep with worry. There is good news though. Research shows that this painful and dangerous condition can be treated through behavioral changes, therapy, and sometimes medicine.

Behavior Changes to Reduce Stress

There are several steps you can take to help with stress management. Here are some:

  • Learn how to say no to commitments that will sap your energy.
  • Tell close family and friends you’re having a difficult time, and that you welcome and appreciate their support.
  • Take small, simple steps to improve your health, such as exercising or improving your diet.
  • Make quality sleep a priority.
  • Do your best to look at things positively.
  • Don’t be afraid to reach out for expert therapeutic help.

Medicine

There are several medications available for people suffering from anxiety. These include SSRIs, benzodiazepines, and tricyclic antidepressants.

SSRIs (selective serotonin reuptake inhibitors) stop some of the nerves in your brain from reabsorbing serotonin, which leaves your body with more serotonin and helps improve mood. While generally considered useful for any form of anxiety disorder, SSRIs are also linked with sleep disturbances like insomnia, as well as weight gain and sexual dysfunction.

Benzodiazepines make you less responsive to stress signals. Doing this makes it easier to relax both your muscles and your mind. However, these drugs can lead to addiction.

Tricyclic antidepressants are also effective in treating anxiety and aren’t addictive in the way benzodiazepines can be. They can come with unwanted side effects, though, including blurry vision and constipation.

Diet and Lifestyle

SUPPORTING EXAM STRESS and Kids going back to School.

stress

Tests and exams can be a challenging part of school life for children and young people and their parents or carers. But there are ways to ease the stress.

Watch for signs of stress

Children and young people who are stressed may:

  • worry a lot
  • feel tense
  • have headaches and stomach pains
  • not sleep well
  • be irritable
  • lose interest in food or eat more than normal
  • not enjoy activities they previously enjoyed
  • be negative and have a low mood
  • feel hopeless about the future

Having someone to talk to about their work can help. Support from a parent, tutor or study buddy can help young people share their worries and keep things in perspective.

Encourage your child to talk to a member of school staff who they feel is supportive. If you think your child is not coping, it may also be helpful for you to talk to their teachers.

Try to involve your child as much as possible.

Make sure your child eats well 

A balanced diet is vital for your child’s health, and can help them feel well during exam periods.

Some parents find high-fat, high-sugar and high-caffeine foods and drinks, such as energy drinks, cola, sweets, chocolate, burgers and chips, make their children hyperactive, irritable and moody.

Where possible, involve your child in shopping for food and encourage them to choose some healthy snacks.

Read more about healthy eating for teens.

Help your child get enough sleep 

Good sleep improves thinking and concentration. Most teenagers need 8 to 10 hours’ sleep a night. Learn more about how much sleep children need.

Allow half an hour or so for your child to wind down between studying, watching TV or using a computer and going to bed, to help them get a good night’s sleep.

Cramming all night before an exam is usually a bad idea. Sleep will benefit your child far more than a few hours of panicky last-minute study.

Be flexible during exams

Be flexible around exam time. When your child is revising all day, do not worry about household jobs left undone or untidy bedrooms.

Staying calm yourself can help. Remember, exams do not last forever.

The Family Lives website has more about coping with exam stress.

Help them study

Make sure your child has somewhere comfortable to study. Ask them how you can support them with their revision.

Help them come up with practical ideas that will help them revise, such as drawing up a revision schedule or getting hold of past papers for practice.

To motivate your child, encourage them to think about their goals in life and see how their revision and exams are related to them.

Talk about exam nerves

Remind your child that it’s normal to feel anxious. Nervousness is a natural reaction to exams. The key is to put these nerves to positive use.

If anxiety is getting in the way rather than helping, encourage your child to practise the activities they’ll be doing on the day of the exam. This will help it feel less scary.

For example, this may involve doing practice papers under exam conditions or seeing the exam hall beforehand. School staff should be able to help with this.

Help your child face their fears and see these activities through, rather than avoiding them.  

Encourage them to think about what they know and the time they’ve already put into studying to help them feel more confident.

Encourage exercise during exams

Exercise can help boost energy levels, clear the mind and relieve stress. It does not matter what it is – walking, cycling, swimming, football and dancing are all effective.

Activities that involve other people can be particularly helpful.

Support group Childline says many children who contact them feel that most pressure at exam time comes from their family.

Listen to your child, give them support and avoid criticism.

Before they go in for a test or exam, be reassuring and positive. Let them know that failing is not the end of the world. If things do not go well they may be able to take the exam again.

After each exam, encourage your child to talk it through with you. Discuss the parts that went well rather than focusing on the questions they found difficult. Then move on and focus on the next test, rather than dwelling on things that cannot be changed.

Make time for treats

With your child, think about rewards for doing revision and getting through each exam.

Rewards do not need to be big or expensive. They can include simple things like making their favourite meal or watching TV.

When the exams are over, help your child celebrate by organising an end-of-exams treat.

When to get help

Some young people feel much better when exams are over, but that’s not the case for all young people.

Get help if your child’s anxiety or low mood is severe, persists and interferes with their everyday life. Seeing a GP is a good place to start.

Some basic rules coming up to exam time

A quiet place to study – A suitable environment to study is important to help concentration levels.

A balanced diet – Good nutrition is essential at any time of year, but especially during exam time. Batch cook some healthy meals and stock up on nutritious snacks. Having some of the student’s favourite dinner to hand is important too.

Omega 3 is essential to fuel the hard-working brain at this time. Keep brain and vision in tip top shape by making sure to top up your good fats daily. Consider taking Cleanmarine® Krill Oil High Strength. It contains 590mg of concentrated, high strength Omega 3 Krill Oil. This concentrated formula of EPA, DHA, Astaxanthin and Choline provides the essential fatty acids required for the normal function of the heart, brain and vision. DHA contributes to the maintenance of normal brain function and vision, the beneficial effect is obtained with a daily intake of 250mg. Also eating 2 – 3 portions of oily fish a week will provides more essential fats for your body. Examples include salmon, mackerel and herring. Easy to cook in steam parcels in the oven with garlic, lemon and oil.

A good night’s sleep – Studying all night may seem like a good idea but if your child doesn’t get enough sleep, they are more likely to forget the information or under perform. When your mind is buzzing with exam questions, quotes and scientific theories, having something to help you switch off, relax and support deep sleep is a must. Try melissa-dreams which contains all-natural ingredients including the herbs lemon balm (Melissa officinalis) and Chamomile in combination with selected B-vitamins, Magnesium and the amino acid L-theanine. Magnesium contributes to a reduction of tiredness and fatigue while vitamins B6 and B12 contribute to the normal function of the nervous system. With no drowsiness or side effects the next day, Melissa Dream helps you to wake up rested and full of energy.

Exercise – Even a 20-minute walk will help your child to relax and destress their mind, this will also help oxygenate the entire body.

Stress is the biggest obstacle to overcome. It’s so important to get enough B vitamins in foods like broccoli. Kale, spinach. Getting your 5-a-day is bound to be the least of your worries as exam time approaches; ironically this is when your nutritional and energy needs are at their highest. Make sure you keep your nutrient and energy levels up with One Nutrition® Organic Power Greens. This is a unique combination of nature’s finest green foods including kale, broccoli, spirulina, wheat grass and barley grass juice powders in a handy capsule or powder to add to your morning smoothie.

Take time out to do something you love such as walking your dog, reading a magazine, chat online to your best friend. Journaling is also therapeutic, to put your thoughts and feelings onto paper. Try family time such as playing a board game to distract your mind from the books for a while.

Don’t forget to celebrate – when the exams are over, go out and celebrate together, hopefully everything will be back to normal by then.

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Can vitamin D really prevent Covid-19? Here’s what the evidence says.


Vitamin D supplement sales have soared amid the pandemic as people try to curb their risk of contracting the novel coronavirus—but some experts are urging caution, noting that not enough research has been done to establish a definitive relationship between taking the supplement and fending off Covid-19.

What the research says about vitamin D and Covid-19

According to Sabyasachi Sen, a professor of endocrinology and medicine at George Washington University (GW), deficiencies of vitamin D are “not rare” and are especially common in older adults, obese people, and people with darker skin—some of the same populations most affected by Covid-19.

While vitamin D is known for protecting bone health, it also helps with the immune system, Sen said. It’s believed that vitamin D improves the function of certain cells, including T cells, which fight off pathogens and can assist in modulating inflammatory responses.

In addition, Sen continued, research has found vitamin D deficiencies have been associated with an increased risk of infection. “Now, what is unknown is whether it’s a cause and effect rather than an association,” he said.

According to the Washington Post, researchers studying the relationship between vitamin D and Covid-19 outcomes are interested in precisely that question: whether there’s a cause and effect relationship, or merely an association.

For example, one study, published in JAMA Network Open, looked at the health records of 489 people in Chicago and found patients with a vitamin D deficiency in the year prior to testing for Covid-19 were 77% more likely to test positive for the disease than those with normal vitamin D levels. Taking a converse approach, another study looked at a small group of Covid-19 patients in Italy who had been hospitalized with acute respiratory failure and found that 81% of them had a vitamin D deficiency.

Meanwhile, an experimental study in France at a nursing home with 66 people found that taking vitamin D supplements was “associated with less severe Covid-19 and a better survival rate.” Similarly, a study in South Korea of 200 people found that a deficiency of vitamin D could “decrease the immune defenses against Covid-19 and cause progression to severe disease.” And a small study in Spain involving 76 hospitalized Covid-19 patients found that those treated with calcifediol—an activated version of vitamin D, distinct from the over-the-counter supplement—seemed to curb the severity of the disease.

On the flipside, however, a recent paper considered by the National Institute for Health and Care Excellence in the United Kingdom looked at vitamin D levels from up to 14 years ago and didn’t find any correlation between vitamin D levels and Covid-19 mortality. And while the lead author of that study has in other papers called for further research on the link between vitamin D and Covid-19 outcomes, the researchers concluded, “For now, recommendations for vitamin D supplementation to lessen Covid-19 risks appear premature and, although they may cause little harm, they could provide false reassurance leading to changes in behaviour that increase risk of infections.”

Similarly, a double-blind randomized controlled trial of 240 patients in Brazil, which has yet to be peer-reviewed, found that one large dose of vitamin D didn’t reduce hospital stay length or mortality rates among patients with a severe case of Covid-19 compared with those in a placebo group.

Correlation—not necessarily causation

“We do know that people who have lower blood levels of vitamin D tend to have a higher risk of being infected with Covid-19 and having severe Covid-19 illness,” JoAnn Manson, chief of the Division of Preventive Medicine at Brigham and Women’s Hospital, said. “But as we say in epidemiology, ‘Correlation doesn’t prove causation.’ We don’t know for sure that the low vitamin D level is causing an increased risk of Covid-19.”

According to Natasha Chida, an infectious disease expert and assistant professor of medicine at Johns Hopkins University, people who have a vitamin D deficiency typically have other health factors that could affect how likely they are to develop a severe case of Covid-19—and people who do develop diseases such as Covid-19 often experience a drop in vitamin D levels.

“Unless you take into account all those factors and separate all those out and look at just vitamin D … it’s really hard to make any inferences about what vitamin D is doing here,” she said.

Chida added that there’s “some biologic plausibility” that vitamin D could help Covid-19 patients. “It’s just that despite years of research into the use of vitamin D in respiratory tract infections, there still hasn’t really been a clear, slam-dunk answer that there’s a benefit.”

Research into the relationship is ongoing, however. According to the Washington Times, about 70 clinical trials assessing vitamin D and Covid-19 have been filed in the U.S. National Library of Medicine database.

Should you take vitamin D supplements?

As of now, experts say people who know they have vitamin D deficiencies should continue their treatment, and those thinking about taking supplements should talk to their health care provider first, given there’s no firm evidence that vitamin D supplements curb people’s risk of infection or serious Covid-19 illness.

“People should be wary of taking mega doses of vitamins or unproven interventions specifically for Covid-19, because we don’t have good quality data yet to suggest that this is of any help,” Hana Akselrod, an infectious disease specialist at GW, said.

Instead of supplements, people can add more vitamin D to their lives by being outdoors for 15 or 20 minutes a day, Akselrod added. And some foods, such fatty fish or fortified dairy products, could also improve vitamin D levels, Manson said.

“There are all of the positive confluences around nutrition and outdoor exercise that aren’t just limited to the number of how many units of vitamin D you get every day,” Akselrod said. “And on top of that, people absolutely need to continue all the other safety precautions, like masking and safe distancing and avoiding gatherings, because we’re in the most dangerous phase of the pandemic yet”.

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COVID-19 will likely be with us forever. Here’s how we’ll live with it.

As COVID-19 continues to run its course, the likeliest long-term outcome is that the virus SARS-CoV-2 becomes endemic in large swaths of the world, constantly circulating among the human population but causing fewer cases of severe disease. Eventually—years or even decades in the future—COVID-19 could transition into a mild childhood illness, like the four endemic human coronaviruses that contribute to the common cold.

“My guess is, enough people will get it and enough people will get the vaccine to reduce person-to-person transmission,” says Paul Duplex, director of the University of Pittsburgh’s Center for Vaccine Research. “There will be pockets of people who won’t take [the vaccines], there will be localized outbreaks, but it will become one of the ‘regular’ coronaviruses.”

But this transition won’t happen overnight. Experts say that SARS-CoV-2’s exact post-pandemic trajectory will depend on three major factors: how long humans retain immunity to the virus, how quickly the virus evolves, and how widely older populations become immune during the pandemic itself.

Depending on how these three factors shake out, the world could be facing several years of a halting post-pandemic transition—one marked by continued viral evolution, localized outbreaks, and possibly multiple rounds of updated vaccinations.

“People have got to realize, this is not going to go away,” says Roy Anderson, an infectious disease epidemiologist at Imperial College London. “We’re going to be able to manage it because of modern medicine and vaccines, but it’s not something that will just vanish out of the window.”

The long road to another common cold

One of the essential factors governing the future of COVID-19 is our immunity to the illness. Immunity to any pathogen, including SARS-CoV-2, isn’t binary like a light switch. Instead, it’s more like a dimmer switch: The human immune system can confer varying degrees of partial protection from a pathogen, which can stave off severe illness without necessarily preventing infection or transmission.

In general, the partial protection effect is one of the reasons why the four known endemic human coronaviruses—the ones that cause a common cold—have such mild symptoms. A 2013 study in BMC Infectious Diseases shows that on average, humans are first exposed to all four of these coronaviruses between the ages of three and five-part of the first wave of infections that young children experience.

These initial infections lay the foundation for the body’s future immune response. As new variants of the endemic coronaviruses naturally evolve, the immune system has a head start in fighting them off—not enough to eradicate the virus instantly, but enough to ensure that symptoms don’t progress much beyond the sniffles.

“The virus is also its own enemy. Every time it infects you, it tops up your immunity,” says Marc Veldhoen, an immunologist at the Portugal’s University of Lisbon.

Past studies make clear that partial immunity can keep people from getting seriously ill, even as coronaviruses successfully enter their systems. Long-term, the same is likely to be true for the new coronavirus. Emory University postdoctoral fellow Jennie Lavine modeled SARS-CoV-2’s post-pandemic trajectory based on the 2013 study’s data, and her results—published in Science on January 12—suggest that if SARS-CoV-2 behaves like other coronaviruses, it will likely morph into mild nuisance years to decades from now.

This transition from pandemic to minor ailment, however, depends on how the immune response to SARS-CoV-2 holds up over time. Researchers are actively examining the body’s “immunological memory” of the virus. A study published in Science on January 6 tracked the immune response of 188 COVID-19 patients for five to eight months post-infection, and while individuals are varied, about 95 percent of patients had measurable levels of immunity.

“Immunity is waning, but certainly not gone, and I think this is key,” says Lavine, who wasn’t involved with the study.

In fact, it’s even possible that one of the cold-causing coronaviruses sparked a serious outbreak in the 1800s before fading into the litany of mild, commonplace human pathogens. Based on the spread of its family tree, researchers estimated in 2005 that the endemic coronavirus OC43 entered humans sometime in the late 19th century, likely the early 1890s. The timing has led some researchers to speculate that the original version of OC43 may have caused the “Russian flu” pandemic of 1890, which was noted for its unusually high rate of neurological symptoms—a noted effect of COVID-19.

“There’s no hard proof, but there are a lot of indications that this wasn’t an influenza pandemic but a corona-pandemic,” Veldhoen says.

The crucible of evolution

Though the carnage of past coronaviruses has faded over time, the road to a relatively painless coexistence between humans and SARS-CoV-2 will likely be bumpy. In the medium-term future, the impact of the virus will depend largely on its evolution.

SARS-CoV-2 is spreading uncontrollably around the world, and with every new replication, there’s a chance for mutations that could help the virus more effectively infect human hosts.

The human immune system, while protecting many of us from a serious illness, is also acting as an evolutionary crucible, putting pressure on the virus that selects for mutations that make it bind more effectively to human cells. The coming months and years will reveal how well our immune systems can keep up with these changes.

New SARS-CoV-2 variants also make widespread vaccination and other transmission-blocking measures, such as face masks and distancing, more crucial than ever. The less the virus spreads, the fewer opportunities it has to evolve.

We’re going to be able to manage it because of modern medicine and vaccines, but it’s not something that will just vanish out of the window.

ROY ANDERSONIMPERIAL COLLEGE LONDON

Current vaccines should still work well enough against emerging variants, such as the B.1.1.7 lineage first found in the United Kingdom, to prevent many cases of serious illness. Vaccines and natural infections create diverse swarms of antibodies that glom onto many different parts of SARS-CoV-2’s spike protein, which means that a single mutation can’t make the virus invisible to the human immune system.

Mutations may produce future variants of SARS-CoV-2 that partially resist current vaccines, however. In a preprint posted on November 19 and updated on January 19, Duplex and his colleagues show that mutations that delete parts of the SARS-CoV-2 genome’s spike protein region prevent certain human antibodies from binding.

“What I’ve learned from our own work is how deviously beautiful evolution is,” Duplex says.

Other labs have found that mutations in 501Y.V2, the variant first found in South Africa, are especially effective at helping the virus elude antibodies. Out of 44 recovered COVID-19 patients in South Africa, blood extracts from 21 of the patients didn’t effectively neutralize the 501Y.V2 variant, according to another preprint published on January 19. Those 21 people had mild to moderate cases of COVID-19, however, so their antibody levels were lower, to begin with, perhaps explaining why their blood did not neutralize the 501Y.V2 variant.

So far, currently authorized vaccines—which spur the production of high levels of antibodies—seem to be effective against the most concerning variants. In a third preprint published on January 19, researchers showed that antibodies from 20 people who had received the Pfizer-BioNTech or Moderna vaccines didn’t bind quite as well to viruses with the new mutations as they did to earlier variants—but they still bound, suggesting the vaccines will still protect against severe illness.

The new variants bring other threats as well. Some, such as B.1.1.7, appear to be more transmissible than earlier forms of SARS-CoV-2, and if left to spread uncontrollably, these variants could make many more people severely ill, which risks overwhelming healthcare systems around the world and even higher death tolls. Veldhoen adds that new variants also may pose a greater risk of reinfection to recovered COVID-19 patients.

Researchers are closely monitoring the new variants. If vaccines need to be updated in the future, Anderson says that it could be done quickly—in roughly six weeks for currently authorized mRNA vaccines, such as those made by Pfizer-BioNTech and Moderna. That timetable, though, doesn’t account for the regulatory approvals that updated vaccines would need to go through.

Anderson adds that depending on how the evolution of the virus progresses, lineages of SARS-CoV-2 may arise that are distinct enough that vaccines will need to be tailored to specific regions akin to vaccines for pneumococcus. To successfully guard against SARS-CoV-2 going forward, we will need a global monitoring network similar to the worldwide reference laboratories used to collect, sequence, and study variants of influenza.

“We’re going to have to live with it, we’re going to have to have constant vaccination, and we’re constantly going to have to have a very sophisticated molecular surveillance program to keep track of how the virus is evolving,” Anderson says.

The promise and challenge of widespread vaccination

Experts agree that transitioning beyond a pandemic depends on the prevalence of immunity, especially among older and more vulnerable populations. Younger people, especially children, will build up immunity to SARS-CoV-2 over a lifetime of exposure to the virus. Today’s adults have had no such luxury, leaving their immune systems naive and exposed.

The exact threshold for achieving population-wide immunity that slows down the virus’s spread will depend on how contagious future variants become. But so far, research of early variants of SARS-CoV-2 suggests at least 60 to 70 percent of the human population will need to become immune to end the pandemic phase.

This immunity can be achieved in one of two ways: large-scale vaccination, or recovery from natural infections. But achieving widespread immunity through uncontrolled spread comes at a terrible cost: hundreds of thousands more deaths and hospitalizations around the world. “If we don’t want to push forward vaccines and champion vaccines, we have to decide collectively how many old people we want to die—and I don’t want to be the one making that decision,” Duplex says.

Jeffrey Shaman, an infectious diseases expert at Columbia University, points out that the global push for vaccines also exposes existing inequities in global health. In a widely shared map from December, The Economist Intelligence Unit estimated that rich countries such as the U.S. will have widely accessible vaccines by early 2022, which may not happen for poorer countries in Africa and Asia until as late as 2023.

Efforts to vaccinate the developing world hinge, in part, on vaccines that can be stored with standard refrigeration, such as the vaccines under development by Oxford/AstraZeneca and Johnson & Johnson. (See the latest on COVID-19 vaccine development around the world.)

As of the week of January 18, according to a World Health Organization estimate, some 40 million COVID-19 vaccine doses have been administered around the world, mostly in high-income countries. In Africa, only two countries, Seychelles and Guinea, have started providing vaccines. And in Guinea, a low-income country, only 25 people have received doses.

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