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Coronavirus immunity: Why a positive antibody test doesn’t mean you’re immune. – Vox.com

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Recently, the World Health Organization put out a buzzkill of a statement: “There is currently no evidence that people who have recovered from Covid-19 and have antibodies are protected from a second infection.”

Ugh, right?

In the United States, nearly a million people have been infected with the SARS-CoV-2 virus that causes Covid-19 as of April 28. Most of those people have recovered from the virus, and want to know if they’re protected going forward. Others who experienced mild symptoms or none at all may want an antibody test to see if they were infected.

At first glance, the WHO statement is confusing: Isn’t the presence of antibodies — the molecules your immune system makes to target and stop a specific virus — a good thing? Aren’t they typically the thing you need to fight off another viral infection?

They’re certainly not a bad sign. But experts in immunology and virology tell me that the WHO is right: The detection of antibodies to Covid-19 is not enough to declare a person immune because we don’t yet know how immunity to this virus works.

“We don’t yet have reliable data about protective immunity,” Angela Rasmussen, a Columbia University virologist, says. Much more scientific work needs to be done to make sure the presence of, and quality of, antibodies detected in a test confers immunity. Scientists also need to figure out how long that immunity lasts. Finally, there are also concerns about the reliability of some of the antibody tests. It’s not helpful if antibody tests have a high rate of false positives and false negatives.

All this doesn’t mean the antibody tests are useless; they may still play a crucial role in helping us understand how to beat this pandemic.

But the WHO doesn’t want anyone who tests positive for antibodies to feel like they’ve acquired a superpower. “There is not enough evidence about the effectiveness of antibody-mediated immunity to guarantee the accuracy of an ‘immunity passport’ or ‘risk-free certificate,’” the WHO says.

Positive antibody tests are certainly suggestive of immunity, but they don’t show the complete picture of immunity. Here’s what will.

First off, antibodies: What are they?

Antibodies are molecules produced by your adaptive immune system. This is the system that creates and mounts an individualized defense to a particular pathogen that enters your body. Antibodies are specific: They target one antigen (i.e., a foreign infectious protein, like those found on a virus) and help clear it from our bodies. There are all sorts of antibodies. There are ones that merely tag a virus and call for other immune cells to react to it. And then there are neutralizing antibodies: These are the molecules that will prevent a virus or pathogen from infecting more of your cells.

“When you first get infected with SARS-Cov-2, it usually takes anywhere from 10 to 14 days to make antibodies that are effective,” says Vineet Menachery, an immunologist who studies coronaviruses at the University of Texas Medical Branch. “That immunity actually peaks between four and eight weeks after you’ve been infected. The antibodies are really powerful at that point.”

Ideally, doctors want to find neutralizing antibodies in someone who has recovered from Covid-19. But that’s trickier than it sounds.

“There are two main types of antibody tests,” Menachery explains. The first just looks for antibodies and can be completed in a few hours. This is called an ELISA test (short for enzyme-linked immunosorbent assay).

How the test works is kind of simple in concept. “The test relies on a plate that is coated with a viral protein of interest,” the Johns Hopkins Center for Health Security explains. Basically, the blood of a person is added to that plate, and the test just looks for whether there are any antibodies that stick to the viral protein. A positive ELISA test tells a doctor there are antibodies in the blood. But, critically, it does not tell them much about their quality.

The second test is more involved, and rarer. It’s called a serum neutralization test, and it takes a few days to process. It not only looks for antibodies, it then exposes those antibodies to a virus in a cell culture to see how effective the antibodies are in stopping the virus.

Ideally, scientists will correlate the two tests and figure out which concentrations of antibodies confer the highest level of immunity. “This work is ongoing,” Menachery says. It’s still not known what levels of antibodies are needed to have lasting, protective immunity. (Scientists are also still working out whether the presence of antibodies also means you can’t give the virus to someone else.)

Serum neutralization studies aren’t the only thing needed to crack the immunity code.

That’s because what happens in a little pool of blood may not always translate to what happens in the vastly complex human body. We also need further studies called “correlate of protection studies.” These are longitudinal studies that track patients over time, “following them to see if they develop reinfection; and comparing the antibody levels and other immune markers between those who are reinfected and those who are not,” Saad Omer, director of the Yale Institute for Global Health, says. “There are other study designs, but this is the overall concept.”

There have been reports of a few patients out of China who had mild symptoms of Covid-19 who did not have detectable neutralizing antibodies after recovery, though they did have another form of antibody that binds to the virus. “It’s unclear whether they have protective immunity,” Nature reports. Tracking these sorts of people long term, for instance, can help us better understand what mix of antibodies is necessary for enduring immunity.

These types of longitudinal studies take a long time to produce data. But in the meantime, researchers can also look at results from convalescent plasma therapy trials to gauge which antibodies, and in what numbers, are most likely to neutralize the virus. Convalescent plasma therapy is when parts of the blood of people who have recovered from the disease are used to treat those still experiencing symptoms. That plasma contains antibodies. And if these trials are effective, “that suggests that antibodies are capable of neutralizing virus,” Rasmussen says.

Even if people do become immune, “one thing we don’t know about still is how long that immunity would last,” Rasmussen says. “And that’s unfortunately not something we can determine until we wait months or years in the future, and test again and see if those antibodies are still there.”

For reasons scientists don’t quite understand, for some infections, someone’s immunity never wanes. People who are immune to smallpox, for example, are immune for life: Antibodies that protect against smallpox have been found as long as 88 years after a vaccination.

Less reassuring here is that scientists have observed antibody levels for other coronaviruses (there are four coronavirus strains that infect people as the common cold) can wane over a period of years. A few weeks after an infection, antibody levels will be at their highest. But “a year from now, that number is likely going to be a little bit lower, and five years from now it’s likely to be potentially a lot lower or a little bit lower, and we don’t know the factors that change that,” Menachery says.

Adding to the pessimism: Just recently, Columbia University researchers published a preliminary study that found that some people got reinfected with a coronavirus (one that causes the common cold) within a year.

However, even if you lose the antibodies, it doesn’t mean you are again completely susceptible to the virus. Yes, none of this is simple.

There have been a few experiments where people were voluntarily exposed to a coronavirus strain that produces a common cold. These studies show it’s common for the antibodies to these other coronavirus strains to decline after a year or so.

“The majority of people that don’t have serum-neutralizing antibodies [i.e., antibodies that take out the virus], they get infected again, but they didn’t get that sick,” Menachery says. You couldn’t do this type of test for Covid-19, he adds; it’s too dangerous

Luckily, even if your antibodies against a coronavirus decline, your body has a backup plan.

Certain types of B-cells (immune system cells that make antibodies) become memory B-cells. These save the instructions for producing a particular antibody, but they aren’t active. Instead, they hide out — in your spleen, in your lymph nodes, perhaps at the original site of your infection — waiting for a signal to start producing antibodies again.

With the memory B-cells in reserve, instead of waiting two weeks or more to get antibody production going, “you’ll only have to wait maybe two or three days,” Menachery says. “So that means, yes, you can get infected again, but you may not even know you’re sick. If you do get sick, maybe it’s a very minor infection.”

Generally, he says, the more severe your infection, the more antibodies your immune system will produce, and the longer they’ll stay in your bloodstream post-infection. So, he says, “there is some concern that if you had a mild infection that your level of protection may not last long.”

All that said, antibody tests are still useful. They help a person understand if they have been exposed to the virus. And they can help our public health understanding of how to beat this pandemic.

Antibody serology (blood) tests “are giving you a snapshot,” Sarah Cobey, a scientist who models epidemiology and immunity at the University of Chicago, says. The snapshot is of how many people have come into contact with the virus. If we compare snapshots, “we can start to try to measure the impacts of different things like school closures versus workplace closures versus shelter in place, and isolation and quarantine.” To sum up: Widespread antibody testing can help us understand which public health measures are working to beat this virus.

But on the individual level, if you get an antibody test back and it’s positive, what should you do?

Well, for one, know that the tests may be of varying quality and accuracy. The Food and Drug Administration “has not reviewed the vast majority of tests on the market, and their validity, particularly point-of-care blood tests that promise rapid results within minutes, isn’t clear,” Kaiser Health News reports. More work needs to be done to validate the tests and make sure the tests can distinguish antibodies for SARS-CoV-2 and antibodies for other viruses in the coronavirus family.

But, overall, a positive antibody test “probably means that the person is likely protected from second infection,” Akiko Iwasaki, an immunobiology professor at the Yale School of Medicine, says. But it does not say whether a person is still infectious. And it does not necessarily mean that person is immune to future Covid-19 infections. Or if they are immune, it’s unclear how long that protective immunity might last.

So what should one do?

“Keeping social distancing behavior until we know better what antibody results mean is a good idea,” Iwasaki says.


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What’s the greatest holiday gift: lips, hair, skin? Give the gift of great skin this holiday season

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Give the gift of great skin this holiday season

Skinstitut Holiday Gift Kits take the stress out of gifting

Toronto, October 31, 2024 – Beauty gifts are at the top of holiday wish lists this year, and Laser Clinics Canada, a leader in advanced beauty treatments and skincare, is taking the pressure out of seasonal shopping. Today, Laser Clincs Canada announces the arrival of its 2024 Holiday Gift Kits, courtesy of Skinstitut, the exclusive skincare line of Laser Clinics Group.

In time for the busy shopping season, the limited-edition Holiday Gifts Kits are available in Laser Clinics locations in the GTA and Ottawa. Clinics are conveniently located in popular shopping centers, including Hillcrest Mall, Square One, CF Sherway Gardens, Scarborough Town Centre, Rideau Centre, Union Station and CF Markville. These limited-edition Kits are available on a first come, first served basis.

“These kits combine our best-selling products, bundled to address the most relevant skin concerns we’re seeing among our clients,” says Christina Ho, Senior Brand & LAM Manager at Laser Clinics Canada. “With several price points available, the kits offer excellent value and suit a variety of gift-giving needs, from those new to cosmeceuticals to those looking to level up their skincare routine. What’s more, these kits are priced with a savings of up to 33 per cent so gift givers can save during the holiday season.

There are two kits to select from, each designed to address key skin concerns and each with a unique theme — Brightening Basics and Hydration Heroes.

Brightening Basics is a mix of everyday essentials for glowing skin for all skin types. The bundle comes in a sleek pink, reusable case and includes three full-sized products: 200ml gentle cleanser, 50ml Moisture Defence (normal skin) and 30ml1% Hyaluronic Complex Serum. The Brightening Basics kit is available at $129, a saving of 33 per cent.

Hydration Heroes is a mix of hydration essentials and active heroes that cater to a wide variety of clients. A perfect stocking stuffer, this bundle includes four deluxe products: Moisture 15 15 ml Defence for normal skin, 10 ml 1% Hyaluronic Complex Serum, 10 ml Retinol Serum and 50 ml Expert Squalane Cleansing Oil. The kit retails at $59.

In addition to the 2024 Holiday Gifts Kits, gift givers can easily add a Laser Clinic Canada gift card to the mix. Offering flexibility, recipients can choose from a wide range of treatments offered by Laser Clinics Canada, or they can expand their collection of exclusive Skinstitut products.

 

Brightening Basics 2024 Holiday Gift Kit by Skinstitut, available exclusively at Laser Clincs Canada clinics and online at skinstitut.ca.

Hydration Heroes 2024 Holiday Gift Kit by Skinstitut – available exclusively at Laser Clincs Canada clinics and online at skinstitut.ca.

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Here is how to prepare your online accounts for when you die

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LONDON (AP) — Most people have accumulated a pile of data — selfies, emails, videos and more — on their social media and digital accounts over their lifetimes. What happens to it when we die?

It’s wise to draft a will spelling out who inherits your physical assets after you’re gone, but don’t forget to take care of your digital estate too. Friends and family might treasure files and posts you’ve left behind, but they could get lost in digital purgatory after you pass away unless you take some simple steps.

Here’s how you can prepare your digital life for your survivors:

Apple

The iPhone maker lets you nominate a “ legacy contact ” who can access your Apple account’s data after you die. The company says it’s a secure way to give trusted people access to photos, files and messages. To set it up you’ll need an Apple device with a fairly recent operating system — iPhones and iPads need iOS or iPadOS 15.2 and MacBooks needs macOS Monterey 12.1.

For iPhones, go to settings, tap Sign-in & Security and then Legacy Contact. You can name one or more people, and they don’t need an Apple ID or device.

You’ll have to share an access key with your contact. It can be a digital version sent electronically, or you can print a copy or save it as a screenshot or PDF.

Take note that there are some types of files you won’t be able to pass on — including digital rights-protected music, movies and passwords stored in Apple’s password manager. Legacy contacts can only access a deceased user’s account for three years before Apple deletes the account.

Google

Google takes a different approach with its Inactive Account Manager, which allows you to share your data with someone if it notices that you’ve stopped using your account.

When setting it up, you need to decide how long Google should wait — from three to 18 months — before considering your account inactive. Once that time is up, Google can notify up to 10 people.

You can write a message informing them you’ve stopped using the account, and, optionally, include a link to download your data. You can choose what types of data they can access — including emails, photos, calendar entries and YouTube videos.

There’s also an option to automatically delete your account after three months of inactivity, so your contacts will have to download any data before that deadline.

Facebook and Instagram

Some social media platforms can preserve accounts for people who have died so that friends and family can honor their memories.

When users of Facebook or Instagram die, parent company Meta says it can memorialize the account if it gets a “valid request” from a friend or family member. Requests can be submitted through an online form.

The social media company strongly recommends Facebook users add a legacy contact to look after their memorial accounts. Legacy contacts can do things like respond to new friend requests and update pinned posts, but they can’t read private messages or remove or alter previous posts. You can only choose one person, who also has to have a Facebook account.

You can also ask Facebook or Instagram to delete a deceased user’s account if you’re a close family member or an executor. You’ll need to send in documents like a death certificate.

TikTok

The video-sharing platform says that if a user has died, people can submit a request to memorialize the account through the settings menu. Go to the Report a Problem section, then Account and profile, then Manage account, where you can report a deceased user.

Once an account has been memorialized, it will be labeled “Remembering.” No one will be able to log into the account, which prevents anyone from editing the profile or using the account to post new content or send messages.

X

It’s not possible to nominate a legacy contact on Elon Musk’s social media site. But family members or an authorized person can submit a request to deactivate a deceased user’s account.

Passwords

Besides the major online services, you’ll probably have dozens if not hundreds of other digital accounts that your survivors might need to access. You could just write all your login credentials down in a notebook and put it somewhere safe. But making a physical copy presents its own vulnerabilities. What if you lose track of it? What if someone finds it?

Instead, consider a password manager that has an emergency access feature. Password managers are digital vaults that you can use to store all your credentials. Some, like Keeper,Bitwarden and NordPass, allow users to nominate one or more trusted contacts who can access their keys in case of an emergency such as a death.

But there are a few catches: Those contacts also need to use the same password manager and you might have to pay for the service.

___

Is there a tech challenge you need help figuring out? Write to us at onetechtip@ap.org with your questions.

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Pediatric group says doctors should regularly screen kids for reading difficulties

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The Canadian Paediatric Society says doctors should regularly screen children for reading difficulties and dyslexia, calling low literacy a “serious public health concern” that can increase the risk of other problems including anxiety, low self-esteem and behavioural issues, with lifelong consequences.

New guidance issued Wednesday says family doctors, nurses, pediatricians and other medical professionals who care for school-aged kids are in a unique position to help struggling readers access educational and specialty supports, noting that identifying problems early couldhelp kids sooner — when it’s more effective — as well as reveal other possible learning or developmental issues.

The 10 recommendations include regular screening for kids aged four to seven, especially if they belong to groups at higher risk of low literacy, including newcomers to Canada, racialized Canadians and Indigenous Peoples. The society says this can be done in a two-to-three-minute office-based assessment.

Other tips encourage doctors to look for conditions often seen among poor readers such as attention-deficit hyperactivity disorder; to advocate for early literacy training for pediatric and family medicine residents; to liaise with schools on behalf of families seeking help; and to push provincial and territorial education ministries to integrate evidence-based phonics instruction into curriculums, starting in kindergarten.

Dr. Scott McLeod, one of the authors and chair of the society’s mental health and developmental disabilities committee, said a key goal is to catch kids who may be falling through the cracks and to better connect families to resources, including quicker targeted help from schools.

“Collaboration in this area is so key because we need to move away from the silos of: everything educational must exist within the educational portfolio,” McLeod said in an interview from Calgary, where he is a developmental pediatrician at Alberta Children’s Hospital.

“Reading, yes, it’s education, but it’s also health because we know that literacy impacts health. So I think that a statement like this opens the window to say: Yes, parents can come to their health-care provider to get advice, get recommendations, hopefully start a collaboration with school teachers.”

McLeod noted that pediatricians already look for signs of low literacy in young children by way of a commonly used tool known as the Rourke Baby Record, which offers a checklist of key topics, such as nutrition and developmental benchmarks, to cover in a well-child appointment.

But he said questions about reading could be “a standing item” in checkups and he hoped the society’s statement to medical professionals who care for children “enhances their confidence in being a strong advocate for the child” while spurring partnerships with others involved in a child’s life such as teachers and psychologists.

The guidance said pediatricians also play a key role in detecting and monitoring conditions that often coexist with difficulty reading such as attention-deficit hyperactivity disorder, but McLeod noted that getting such specific diagnoses typically involves a referral to a specialist, during which time a child continues to struggle.

He also acknowledged that some schools can be slow to act without a specific diagnosis from a specialist, and even then a child may end up on a wait list for school interventions.

“Evidence-based reading instruction shouldn’t have to wait for some of that access to specialized assessments to occur,” he said.

“My hope is that (by) having an existing statement or document written by the Canadian Paediatric Society … we’re able to skip a few steps or have some of the early interventions present,” he said.

McLeod added that obtaining specific assessments from medical specialists is “definitely beneficial and advantageous” to know where a child is at, “but having that sort of clear, thorough assessment shouldn’t be a barrier to intervention starting.”

McLeod said the society was partly spurred to act by 2022’s “Right to Read Inquiry Report” from the Ontario Human Rights Commission, which made 157 recommendations to address inequities related to reading instruction in that province.

He called the new guidelines “a big reminder” to pediatric providers, family doctors, school teachers and psychologists of the importance of literacy.

“Early identification of reading difficulty can truly change the trajectory of a child’s life.”

This report by The Canadian Press was first published Oct. 23, 2024.

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