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Expert comment on antibody tests for COVID-19

What do we know about the immune response to COVID-19 and how does this differ by age, gender, co-morbidities or other traits? What are the different tests available? How reliable are they? Do the tests show immunity? And do we even know how long immunity to COVID-19 might last.

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By Professor Georgina Ellison-Hughes, Dr Rocio Martinez-Nunez and Dr Rui Ribeiro Galao
Faculty of Life Sciences & Medicine
King’s College London

With promises of antibody tests being rolled out in the next few days, and retailers told not to send home-testing kits as their accuracy is questioned, it is timely to consider what we do and don’t know about these tests. What do we know about the immune response to COVID-19 and how does this differ by age, gender, co-morbidities or other traits? What are the different tests available?  How reliable are they? Do the tests show immunity? And do we even know how long immunity to COVID-19 might last.

What do we know about the immune response to COVID-19?

The immune response to COVID19 can be split into a healthy antiviral immune response or a defective/overactive immune response, which is often implicated in the resulting damage to the lungs and other organs, and then the person can be severely ill. There is a high percentage of patients that get infected with SARS-CoV-2 and do not develop any symptoms, hence the importance of social distancing to protect others since we do not know who can be carrying the virus.

Initially, viral infection switches on antiviral defences. These include interferons and pro-inflammatory cytokines and chemokines, which kill the virus and attract immune cells (neutrophils, monocytes, macrophages and T cells) to the site of infection. The virus enters cells employing ACE2 as a receptor, a protein that is expressed in many cell types and present in the epithelium in the airways.

In the healthy immune response, the innate antiviral defences fight against the virus and virus-specific T cells can later eliminate the infected cells before the virus spreads. Neutralizing antibodies in these individuals can block viral infection, and phagocytic cells such as alveolar macrophages recognize neutralized viruses and apoptotic cells and clear them by phagocytosis. Altogether, these processes lead to clearance of the virus and minimal lung damage, resulting in recovery.

In a defective immune response, there is a hyperactivation of the immune cells in the lungs causing overproduction of pro-inflammatory cytokines (cytokine storm), which eventually damages the lungs. The resulting cytokine storm circulates to other organs, leading to multiple organ damage. 

In patients that are severely ill there is a combination of multi-organ damage, increased coagulation and lymphopenia. Researchers are trying to elucidate the mechanisms underlying these responses and the causes for the hyperactivation of the immune response.

Longer-term immunity is acquired through antibodies made by the B cells of the immune system, which stick around in the blood post-infection. These antibodies can bind to the virus, either neutralizing it directly or marking it for destruction by other immune cells. Studies have found high levels of neutralizing antibodies to SARS-CoV-2 in recently recovered patients. This is the principle behind new trials such as those at Guy’s and St Thomas’ Hospitals in which severely ill patients receive plasma from recovered donors. Memory T cells are another source of long lasting immunity and are generated when a person gets infected, remaining in the blood and responding rapidly when re-infection occurs.

How does the immune response differ by age, gender, co-morbidities and other traits?

As we have observed, everyone responds differently to the virus with most healthy, infected people under the age of 65 making a full recovery. However, there is increased severity with age, and if you have an underlying health condition i.e. cardiovascular disease or diabetes. Black and ethnic minorities also seem more affected.

A retrospective, multicentre cohort study has shown old age, being male and cardiovascular disease co-morbidity are risk factors for mortality of COVID19 (Zhou et al. 2020, The Lancet). The most common cardiovascular co-morbidity as a risk factor for mortality is hypertension, followed by diabetes. Moreover, prevalence of hypertension is highest in the elderly population and advanced age remains the strongest predictor of COVID-19 related death.

Because disease severity is due to not only the viral infection but also the host response, older individuals suffer because they have a progressive decline in immune function with increasing age, called immunosenescence.

Another risk factor to disease severity and dying from COVID19 is being male. The reasons for this are currently unclear, but it has been suggested that women may naturally have stronger immune defences than men. Another possibility is that comorbidities associated with poorer prognosis are more common in men.

What are the various antibody test being trialled in labs, and being sold to the public? 

With no ‘gold standard’ for antibody testing and an incomplete knowledge of the immunology of COVID-19, it has been problematic to evaluate serologic tests. Several lateral flow immunoassays (similar to a pregnancy test) were initially trialled, with ease of use and affordability weighing heavily in their favour. Several of these have presented high sensitivities and specificities and are available to buy by the public (companies such as Alpha and Blue Horizon). The kits manufactured by Roche and Abbott will shortly be available on the NHS. There is a drive now to test different ELISA platforms including Abbott. ELISA takes longer than lateral flow tests but is quite reliable and is the preferred option for large scale testing.

What are the different ways you administer these tests? 

These are all blood tests, and most of them just use a finger prick of blood. The Roche and Abbott tests must be carried out by a doctor and the blood is sent to a laboratory for evaluation. The most commonly used method is to take a blood sample, spin it down in a centrifuge to obtain the plasma serum content of the blood and analyse the presence of antibodies, including neutralising antibodies. Saliva may be another source for antibodies.

Will the antibody test show that the person is immune? 

The test will detect whether you have the antibodies (immunoglobulins, IgG and IgM) against SARS-CoV-2. However, having antibodies does not automatically mean you are ‘immune’ against SARS-CoV-2. Neutralizing antibodies are more ‘effective’ against SARS-CoV-2 and most commercial tests detect only if there is presence/absence of immunoglobulins (Ig).

How reliable are the various tests?

The reliability can differ depending on what Ig’s are being detected and how long after you perform the test following testing positive for SARS-Cov-2. The antibody tests available are those that detect the presence of IgM and/or IgG and inform about current (likely in the case of IgM) or previous (IgG) infection with SARS-CoV-2. However, to determine presence of SARS-CoV-2, i.e. if a person is ‘infectious’, PCR remains as the gold standard.

Roche and Abbott have said the level of accuracy for its SARS-Cov-2 antibody test is high, and it was able to distinguish the antibodies from those for closely related coronaviruses, which have been known to produce positive results in tests made by other companies.

What are IgM and IgG antibodies and how do they affect the interpretation of the test?

Immunoglobulin M (IgM) antibodies are usually the first antibody produced by the immune system when a pathogen attacks. A positive IgM test indicates that you may have been infected recently (peaking at day 7-10 post-infection) and that your immune system has started responding to the virus.  When IgM is detected you may or may not still be infected.

Immunoglobulin G (IgG) antibodies develop in most patients within 7 to 10 days after symptoms of COVID-19 begin. IgG antibodies remain in the blood after an infection has passed. These antibodies indicate that you may have had COVID-19 in the recent past and have developed antibodies that may protect you from future infection. Therefore, an IgG antibody test is most reliable as a source of information about previous infection. Tests that combine measurement of IgM and IgG, and therefore do not distinguish between the two, cannot guarantee the presence of IgG antibodies, which are the ones that in theory confer longer immunity and remain in the bloodstream to protect from future infections.

How long does immunity last for?

In patients at least 14 days after discharge from hospital, studies show have high levels of antibody which suggests that their immune system is armed against further attack. Because SARS-CoV-2 has only been around for 6 months, how long the immunity lasts for is unclear. However, if SARS-CoV-2 is like other coronaviruses, like 2002’s SARS 1, or 2012 MERS, then immunity could last for several years. We think that we should err on the side caution because a recent study, by the group of Professor Lia van der Hoek from the University of Amsterdam tested 10 male individuals regularly over a time span of 35 years for four types of coronaviruses, which cause the common cold. Results showed an alarmingly short duration of protective immunity with frequent reinfections at 12 months post-infection and a substantial reduction in antibody levels as soon as 6 months post-infection. It is of note that respiratory viruses are not great at triggering long-lasting immunity.

Believing that everyone's perspective is important, Zest Magazine has opted to provide an avenue for these perspectives to be known. care to hear the publication's contributing writers; or better yet, do some contributing yourself by contacting info@zestmag.com.

NewsMakers

How to get the best wedding photos ever

Finding the ‘right’ photographer for your wedding is a bit like dating; you can’t make a decision only after checking someone out online. A photographer’s portfolio might be really polished, but you can’t get a real sense of their personality or emotional intelligence. It’s wise to meet with a few photographers or videographers, either in person or via zoom, before you make a final decision.

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According to The New York Times, 2022 will be the biggest year for the wedding industry since 1984. After two years of delays and cancellations, everyone is going to the proverbial chapel to tie the knot. One of the most important elements for many couples are the photos and videos, preserving this special moment forever.

“In the end, having tangible memories you’ll cherish for years to come is a better investment than party favors or fancy table linen,” said Rachel LaCour Niesen, Head of Market Intelligence

A graduate from the Missouri School of Journalism, LaCour Niesen forged a career as a professional wedding photographer and photojournalist where she developed the first CRM for pro photographers. While still continuing her passion in professional photography, LaCour Niesen also serves as Head of Market Intelligence at ShootProof, a platform used by 300,000 photographers to share, deliver, print, & sell their photos. Just in the last year, Shootproof managed wedding galleries received 2.8 million visits per month – and that number is anticipated to grow in 2022. 

Her advice when shopping for a wedding photographer? “Finding the ‘right’ photographer for your wedding is a bit like dating; you can’t make a decision only after checking someone out online. A photographer’s portfolio might be really polished, but you can’t get a real sense of their personality or emotional intelligence. It’s wise to meet with a few photographers or videographers, either in person or via zoom, before you make a final decision.”

For one of the most important days in someone’s life, Rachel has a few “dos” before you say “I Do”

  • Ask friends and family for recommendations. “Word-of-mouth referrals are a great way to curate a list of prospective photographers and videographers.” says Rachel. “After all, your friends and family know you better than anyone else.”
  • Spend time viewing their online portfolios. According to Rachel, “a lot of people can take a few great photos or videos. To tell a more complete “story” of a wedding celebration requires more skill, patience, and thoroughness.”
  • Look closely to see if the photographers and videographers you are interested in have shot weddings in many types of lighting conditions. “It’s pretty easy to capture stunning photos outdoors during “golden hour,” around sunset,” Rachel remarked. “But it’s much, much harder to capture stunning photos in a dimly-lit event space like a hotel ballroom or dance club.”
  • Ask whether photo products are included in their booking fee and/or package price. “To me, every couple should end up having a wedding album or book–a tangible one, not just an online slideshow,” Rachel said. “I still have copies of my grandparent’s wedding photos hanging in my home. They inspire me and bring back so many memories of our family stories. Plus my son is now curious to hear about his great grandparents too and I can point right to those photos and use them to spark conversation.”

Wedding photography does not just document the union itself, but all the family members and friends who came together to celebrate. “Sometimes, the most cherished photo is not that ‘kiss the bride’ moment but that last family image with a beloved grandparent. Weddings are those precious occasions where people rally together in a grand act of joy.”

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Health

How can the self-employed tackle burnout? Expert shares top tips

Self-employed people such as business owners or freelancers may be more susceptible to burnout due to long working hours and the weight of responsibility that they carry.

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Photo by Nubelson Fernandes from Unsplash.com

With workers returning to the office in their greatest numbers since the pandemic, the number of people suffering from burnout or stress-related illnesses is also on the rise.

Self-employed people such as business owners or freelancers may be more susceptible to burnout due to long working hours and the weight of responsibility that they carry. 

For many work and life have become intertwined, fortunately, Private Rehab Clinic Delamere has shared tips on how you can tackle burnout when self-employed and the common signs.  

How you can tackle burnout

1. Set Goals and Priorities

Having a mountain of work, with no plan in place to move forward can sometimes feel overwhelming. It can help to take a step back to assess which of your tasks need prioritising, and which ones will help you to achieve your goals.  

2. Speak to Your Colleagues or Clients

Being honest with the people that you are working with or for, about your mental health can often make things a lot a lot easier. You may be surprised at how understanding other people are of your situation.

By being open with others, you will have a better understanding of what to expect from each other, meaning that you will have a stronger professional relationship going forward.

3. Ask for Help

Never be afraid to ask for help if you feel that your stress is becoming too much to handle and you start to show signs of burnout. Getting external advice through counselling or therapy can give you a new perspective on a situation to guide you through any problems.

If you do not feel comfortable with counselling, then simply reaching out to friends and family can be enough to help you talk through your problems.

4. Schedule Time-Off

Sometimes when work life is becoming too stressful, all you need to do is take a short break from it all. Returning to work after a much-needed break can give a person a more positive mindset.

Those who are self-employed are often in charge of their own schedule and can over look the need to take holidays. In fact, some surveys have shown that nearly one in ten business owners go up to five years without taking a holiday.

5. Consider Changing Things

If your line of work is causing you constant stress and it feels that there truly is no way out, then it may be worth considering if you are genuinely following the right career path for you.

It may be the case that you do not need to change your career path altogether, but that your daily work routine simply needs to be altered. Consider making small changes such as your place of work. If you are stuck in an office or at home all day, you may benefit from finding a co-working space or coffee shop to work in.

Sometimes changes can be as simple as investing in new equipment or simply taking more regular breaks from your working day. By implementing these small changes you are less likely to burnout from stress.

6. Put Self-Care First

Work-life can be demanding, especially for any self-employed people who are under pressure to meet deadlines for various clients. However, when we demand too much of ourselves, it can be damaging to our physical and mental health.

Remind yourself that you come first. Maintaining a healthy sleeping and eating pattern, while keeping up a rewarding social life and strong relationships is more important to your mental well-being than anything you do while on the clock. 

Spotting the signs of burnout

1. Feeling Tired All The Time

If you are waking up feeling exhausted and find that you are still feeling drained even after you have been awake for a few hours and a cup of coffee in your system, then this may be a sign that you have burnout.

2. Lack of Motivation

During burnout, a person may find themselves completely withdrawn from their workplace or work tasks. Simply going through the motions while at work without any kind of motivation – or taking no joy whatsoever from your accomplishments at work – could indicate that you are experiencing burnout.

3. Recurring Health Problems

A person suffering from burnout may experience frequent and recurring headaches and muscle pains, as well as feelings of indigestion and stomach aches.

4. Feeling Irritable

Finding yourself easily irritated or frustrated, even by small things, and then snapping out at others is a possible sign that you are carrying too much stress from work.

6. Self-Deprecating Feelings

When someone is suffering from burnout it can have serious effects on their mental health. A person can have a heightened sense of self-doubt, feel like a failure and even experience impostor syndrome.

A person with burnout may also experience increased feelings of isolation and detachment from their colleagues, friends and family.

7. Increased Procrastination

When burnout occurs a person may find themselves avoiding their responsibilities, regardless of how small those responsibilities may be. Instead, a person will fill their time with procrastination and indulging in comforting distractions.

8. Coping Mechanisms

During burnout, a person may be more likely to turn to other comforts and coping mechanisms such as comfort eating junk food or even consuming alcohol and/or drugs. Engaging in any habit excessively to cope with stress may be a sign of burnout.

9. Change in Sleeping and Eating Habits

Stress can mess with our natural cycle and someone who is experiencing unnaturally high levels of stress may find that their sleeping habits are altered as they end up staying up late and sleeping in.

A person may also find themselves skipping or avoiding regular meal times, having a loss of appetite at some points in the day, or craving comforting junk food at others.

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Nutrition

Tips for great grilling

Follow these easy tips for even tastier meals.

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Photo by Myles Tan from Unsplash.com

Grilling is so fun and delicious – clearly a high point of any summer.  Follow these easy tips for even tastier meals.

  1. Start with a clean grill. 
    Starting with a clean grill will allow the flavor of whatever you’re cooking to shine through and not mix with flavors left behind from whatever you grilled last. It also helps prevent food from sticking. Clean the grill with a sturdy brush while it’s hot, as it will be much easier to clean.
  2. Oil the grill grates. 
    Oiling the grill grates will help prevent lean meats from sticking to the grill. Pour oil on a paper towel, then use tongs to rub the oil on the grill grates – don’t use cooking spray as it will flare up.  Or try this fun grill hack: cut a potato in half and rub the cut side of the potato on hot grill grates, this will make the grill naturally non-stick!
  3. Always make sure your grill is hot. 
    Adding food to a hot grill will give it a wonderful sear on the outside, while keeping it perfectly juicy in the center. It will prevent food from sticking to the grill, and it’s important for cooking safety. 
  4. Use an instant-read meat thermometer to check for a safe and desired temperature. 
    You always want to make sure that food on the grill is cooked to a safe temperature. Use an instant read thermometer to make sure meat is cooked to the proper temperature. Food safety is extremely important, as undercooked food can cause illness.
  5. Use a grill basket. 
    For foods that might fall through the grates and cause flare-ups, use Basquettes. These are incredibly handy for grilling vegetables, seafood, fish, kabobs, stuffed sliders, cheese and fruit. You can use Basquettes with a top so you can flip a whole basket of food over in one motion.
  6. Always let meat rest after removing it from the grill. 
    Depending on the meat, allow it to rest for at least 5-15 minutes before slicing into it. A large piece of meat, such as a tri tip will need more rest time than a smaller steak, like a tenderloin. Resting the meat allows the juices to redistribute throughout the meat for a juicier, more tender piece of meat and tenting under foil helps keep it warm.
  7. Experiment with different cooking techniques.
    Grills can easily become smokers or rotisseries! Make a flattened foil packet of aromatic hardwood and pierce it a few times. Use your Basquettes with the legs on and slip the foil packet beneath. Or put the baskets together and make a rotisserie cage for delicious chicken!
  8. Know whether to cook your foods directly or indirectly. 
    Smaller pieces of meat, like a New York strip steak, that take 20 minutes or less to cook should be grilled over direct heat. Large pieces of meat, like ribs, that take more than 20 minutes to cook should be grilled over indirect heat.
  9.  Add sauce to meat at the end of the grilling process. 
    Adding a glaze or barbecue sauce, especially one with sugar, too early in the cooking process can cause your meat to burn and stick to the grill. If you plan to baste meat with a sauce or glaze, do it in the last 5 minutes of cooking, if the total cooking time is 30 minutes or less. If the total cooking time is over 30 minutes, baste the meat in the last 15 minutes of cooking time.

Bonus tips!

  • Never flatten meat with a spatula when it’s on the grill. This will release all of the juicy flavor in the middle of the meat.
  • Avoid putting cold foods on the grill. Bringing meat to room temperature for 30 minutes will help it cook more evenly.
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