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<ul class="summary-list"><li>A leading <keyword id="8966876" type="UNKNOWN" weightage="60" keywordseo="antibody-test">antibody test</keyword> was approved for use in Europe on Wednesday.</li><li>Medical diagnostics firm <keyword id="48168" type="COMPANY" weightage="60" keywordseo="Abbott">Abbott</keyword> says it will distribute millions of "IgG" tests in Europe by the end of May.</li><li>These tests will likely be useful to governments trying trace the spread, but critically — like all other antibody tests in use — it does not show if a person has immunity.</li><li>The tests were first <a href="https://www.businessinsider.com/abbott-to-make-millions-antibody-tests-coronavirus-by-june-2020-4?r=US&amp;IR=TIR=T">rolled out in the US on April 15</a>, with 4 million units already circulated there in April, Abbott said.</li><li>The test works by locating the antibody protein IgG, which show if a person has had COVID-19. The antibody can last in the body for years after the original infection, the company said.</li><li><a href="https://www.businessinsider.com/?hprecirc-bullet">Visit Business Insider's homepage for more stories</a>.</li></ul>An antibody test claiming 99% accuracy in seeing if people have contracted the <a href="https://www.businessinsider.com/coronavirus-live-updates-latest-news">novel coronavirus</a> has been approved in Europe.Medical diagnostics firm Abbott announced Wednesday that its IgG serology blood test was awarded a CE mark, meaning it complies with EU safety requirements.In a statement shared with Business Insider, Abbott said its test identified with 99% accuracy the presence of COVID-19 in 73 coronavirus-positive patients who took the test 14 days after they showed symptoms.The test works by locating the antibody protein IgG, which show if a person has had COVID-19. The antibody can last in the body for years after the original infection.Tests on 1,070 samples without the <keyword id="1754604" type="PERSON" weightage="60" keywordseo="coronavirus">coronavirus</keyword> also came back with 99% accuracy, the company said.While the test shows if someone has contracted the virus, it does not show if that person has immunity. There is not yet a test in existence that can.The presence of antibodies in the blood does also not guarantee immunity to a virus. It also takes time for antibodies to breed within the human body, meaning the test may not work on someone who is in the early stage of infection. <div type="image" title="The Abbott COVID-19 antibody test in use in a lab." height="1453" width="2907" msid="75473149" hostid="261"></div>Abbott plans to produce and circulate millions of tests for use across Europe, it said. The company already has a number of COVID-19 tests in use in the UK.The same blood test was <a href="https://www.businessinsider.com/abbott-to-make-millions-antibody-tests-coronavirus-by-june-2020-4?r=US&amp;IR=TIR=T">rolled out in the US on April 15</a>, with some 4 million to be produced by the end of the month there, the company said.The antibody tests can only be run through one of Abbott's two widespread laboratory testing machines, which process as many as 200 tests per hour. There are 2,000 machines in the US and 250 in the UK.The test is useful as <a href="https://www.navytimes.com/news/coronavirus/2020/04/16/secdef-majority-of-roosevelt-sailors-with-covid-19-are-asymptomatic-flattop-still-wartime-ready/">some studies have shown that as many as 50% of those carrying the coronavirus show no symptoms</a> at all.The test will likely be useful to governments seeking to trace the spread of the virus and slow the spread of infections.Read the original article on <a href="https://www.businessinsider.com/abbott-coronavirus-antibody-test-99-percent-effective-europe-approved-2020-4">Business Insider</a>

A leading antibody test which claims 99% accuracy has been approved for use in Europe after success in the US

People exposed to higher levels of <keyword id="55910" type="General" weightage="20" keywordseo="air-pollution" source="Orion">air pollution</keyword> before the pandemic are likely to have lower antibody responses to Covid-19 vaccines, suggests a study. In particular, exposure to fine particulate matter (PM2.5), nitrogen dioxide (NO2) and blank carbon (BC) was associated with about a 10 per cent decrease in IgM and IgG antibody responses in people without prior infection, said researchers from the Barcelona Institute for Global Health (ISGlobal), and the Germans Trias i Pujol Research Institute (IGTP) in Spain. The fact that previous infections lead to higher vaccine responses could explain why the effect of pollutants was only observed in people without a prior infection. However, the role of long-term exposure to air pollution on hybrid immunity (infection plus vaccination) deserves further investigation, the researchers warned, in the study published in Environmental Health Perspectives. "Air pollution can induce chronic inflammation, which has been associated with a negative effect on vaccine efficacy," said Carlota Dobano, researcher from ISGlobal. "Our findings are consistent with evidence that persistent organic pollutants reduce vaccine responses in children," she added. Air pollutants have been shown to affect immune responses. Previously it has been linked to adverse health outcomes, including lung cancer, cardiovascular and respiratory disease, and diabetes. The team analysed data from 927 participants (aged 40 to 65 years), who answered questionnaires and gave blood samples in the summer of 2020 (right after the first lockdown) and in 2021 (after the start of Covid-19 vaccination). All had received one or two doses of the main Covid-19 vaccines administered in Spain (made by AstraZeneca, Pfizer or Moderna). The research team measured IgM, IgG and IgA antibodies to five viral antigens (three of them on the Spike protein contained in the vaccine). Exposure to fine particulate matter (PM2.5), black carbon (BC), nitrogen dioxide (NO2) and ozone (O3) was estimated for each participant based on his or her address before the pandemic. The results show that in uninfected individuals, pre-pandemic exposure to PM2.5, NO2 and BC was associated with a 5 per cent to 10 per cent reduction in vaccine-induced Spike antibodies. The decrease in antibodies was shown both for early IgM responses and late responses measured by IgG. The IgG response after the first dose peaked later in participants exposed to higher air pollution levels, and lower IgG levels persisted for several months after vaccination. Results were similar for the three vaccines. The study did not look at whether the reduction in antibody responses led to an increased risk of breakthrough infections and their severity. However, the findings add to the growing body of evidence on the adverse effects of air pollution even at the relatively low levels observed in Western Europe, the researchers said, while calling for stricter air pollution limits. SEE ALSO: <a href="https://www.businessinsider.in/business/news/ipl-2023-to-drive-fantasy-sports-companies-to-2900-3100-crore-revenue/articleshow/99285556.cms">IPL 2023 to drive fantasy sports companies to ₹2,900-3,100 crore revenue, fueled by Tier-2 cities and exciting prizes</a> <a href="https://www.businessinsider.in/tech/news/google-makes-it-easier-for-users-to-delete-their-account-and-data-from-applications/articleshow/99289621.cms">Google makes it easier for users to delete their account and data from applications</a> <a href="https://www.businessinsider.in/tech/news/9-out-10-tvs-sold-in-india-in-2022-were-smart-tvs-and-nearly-all-of-these-tvs-are-assembled-locally/articleshow/99262205.cms">9 out 10 TVs sold in India in 2022 were smart TVs, and nearly all of these TVs are assembled locally</a>

Air pollution can affect your Covid vaccine efficacy: Study

<ul class="summary-list"><li><keyword id="1754604" type="PERSON" weightage="60" keywordseo="coronavirus">Coronavirus</keyword> <keyword id="102007" type="TECHNOLOGY" weightage="60" keywordseo="Antibodies">antibodies</keyword> dwindled to undetectable levels after just two or three months for 40% of asymptomatic people and 13% of symptomatic people, according to a new study.</li><li>Overall, asymptomatic people showed "a weaker immune response" in the months after they were exposed to the coronavirus.</li><li>A poor immune response in people who recover from the virus may not bode well for the development of an effective <keyword id="24209" type="PERSON" weightage="60" keywordseo="vaccine">vaccine</keyword>.</li></ul>People who develop coronavirus-fighting antibodies might not keep them very long, especially if they didn't have symptoms.After just a few months, recovered coronavirus patients may rapidly lose antibodies — blood proteins that fight off the virus and can prevent reinfection — according to a <a href="https://www.nature.com/articles/s41591-020-0965-6">study</a> published Thursday in the journal Nature Medicine. The finding raises new questions about the idea of <a href="https://www.businessinsider.com/coronavirus-immunity-passport-data-gdpr-covid-19-2020-5">immunity passports</a> and could be cause for concern about the development of an effective vaccine.The researchers tested for antibodies in 37 people who had fallen ill and recovered from the virus in the Wanzhou district of China. They also tested 37 others who had tested positive for the virus but never showed symptoms.The study was meant to address two key questions that will inform how the world responds to the pandemic in the coming months: Do most people develop <keyword id="48619" type="PERSON" weightage="60" keywordseo="Immunity">immunity</keyword> after infection? And how long does that protection last?<div type="image" title="A man, who visited Beijing recently, is tested for the COVID-19 coronavirus in Nanjing in China's eastern Jiangsu province on June 15, 2020. - China's capital city raced on June 15 to control a fresh coronavirus outbreak, with 75 cases linked to a single wholesale food market in Beijing where authorities have locked down neighbourhoods and launched a massive test and trace programme. (Photo by STR / AFP) / China OUT (Photo by STR/AFP via Getty Images)" height="2667" width="3556" msid="76454979" hostid="261"></div>For many of the participants in the study, however, antibodies only seemed to last a couple months. About eight weeks after recovery, antibodies dropped to undetectable levels in 40% of the asymptomatic people and in 13% of those who had symptoms.The asymptomatic people overall had "a weaker immune response," the study authors wrote. Their research is some of the first into the immune response among asymptomatic people; previous studies have found that most people who show <keyword id="8763838" type="UNKNOWN" weightage="60" keywordseo="covid-19">COVID-19</keyword> symptoms develop antibodies.It's unclear if low levels of antibodies, even undetectable levels, are enough to confer immunity. Some <a href="https://www.nature.com/articles/s41586-020-2456-9">research</a> has suggested that even low antibody counts could still be enough to prevent reinfection.The Wanzhou study's sample size was small, though, and antibody tests can be <a href="https://www.businessinsider.com/companies-making-coronavirus-immunity-tests-serology-blood-2020-4">unreliable</a> on a person-to-person basis.<h2>Different types of immunity</h2><div type="image" title="antibody test" height="1151" width="1534" msid="76454980" hostid="261"></div>The Wanzhou researchers tested for two types of antibodies: immunoglobulin G (IgG) and immunoglobulin M (IgM). In general, our bodies make IgM first in response to a viral infection, whereas IgG develops over a longer period of time. That means IgG is usually a better indicator of long-term immunity."Even though we don't know what's going on with this disease yet, if IgG confers immunity, that's the more important one that has implications for going back to work," Ania Wajnberg, the director of clinical <keyword id="9037219" type="UNKNOWN" weightage="60" keywordseo="antibody-testing">antibody testing</keyword> at Mount Sinai Hospital in New York, <a href="https://www.businessinsider.com/when-should-i-get-tested-for-coronavirus-antibodies-results-2020-5">previously</a> told Business Insider.Seven people from the new study's asymptomatic group and six from the symptomatic group did not test positive for IgG antibodies three to four weeks after they were exposed to the virus. Even more participants did not have detectable levels of IgM.After just eight weeks, IgG levels had declined in all but three of the people who started out with detectable levels. The drop was steep: a median decrease of 71% for the asymptomatic group and 76% for the symptomatic group. Some participants no longer had detectable IgG at all. The symptomatic people started out with "significantly higher" levels, according to the research.However, all the participants still had another type of antibody that neutralizes the coronavirus's spike protein, though its levels decreased, too.Still, antibodies are not the only way the human body can fight off a virus. It also uses T cells to kill the virus and B cells to rapidly produce new antibodies. Neither of those were measured in the new study. <h2>Vaccines may not protect everybody equally</h2><div type="image" title="coronavirus vaccine trial participant clinical" height="2867" width="3823" msid="76454981" hostid="261"></div>Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, <a href="http://ja.ma/fauci62">said in a livestreamed conversation</a> earlier this month that immune responses to the coronavirus are inconsistent between different patients."I have examples of people who were clearly infected, who are antibody-negative," Fauci said, adding that those people likely have antibodies — just not enough for the test to detect. Other recovered patients, meanwhile, show high antibody counts."It isn't a uniformly robust antibody response," Fauci added.Other coronaviruses — the kind that cause common cold — produce immunity that lasts less than a year, and in some cases just a few months."It may be completely different with this coronavirus," Fauci said. "We don't know."Learning more about humans' natural immune responses to the new coronavirus is crucial, since it informs how a vaccine might work."If the body is capable of making an immune response to clear the virus in natural infection, that's a pretty good proof of concept to say that you're going to make an immune response in response to a vaccine," Fauci said.But he added: "There's never a guarantee, ever, that you're going to get an effective vaccine."If people who get infected and recover on their own don't develop a strong immune reponse, that may not bode well for <a href="https://www.businessinsider.com/fauci-offers-coronavirus-vaccine-timeline-phase-3-trial-2020-6">vaccine development</a>. Still, the Wanzhou study is small, so further research could give scientists a better picture of how immune systems respond to COVID-19.

Coronavirus antibodies may disappear 2 to 3 months after people recover, a new study found

<ul class="summary-list"><li>A woman in Singapore who had COVID-19 in March just gave birth to a baby who has <keyword id="102007" type="TECHNOLOGY" weightage="60" keywordseo="Antibodies">antibodies</keyword> that seem to be protective against the virus, she told a local paper. </li><li>Past research has suggested antibodies against COVID-19 cross the placenta in utero, but little is known about how long the presumed immunity may last and how the timing of infection during <keyword id="6357793" type="UNKNOWN" weightage="60" keywordseo="pregnancy">pregnancy</keyword> plays a role. </li><li>Breast milk also has detectable antibodies against COVID-19 and there's no evidence it transmits the virus, leading health organizations to encourage moms with the illness to breastfeed while taking precautions. </li></ul>When Celine Ng-Chan was 10 weeks pregnant, she was diagnosed with COVID-19. Back then, in March, even less was known about how the coronavirus affected pregnant women and their future children.But now that Ng-Chan, a private tutor in Singapore, gave birth to her son Aldrin in early November, the news is encouraging both for Ng-Chan and other women who have or contract COVID-19 when pregnant. Aldrin is COVID-19-free and appears to have acquired protective antibodies at least temporarily from his mother's illness, Ng-Chan <a href="https://www.straitstimes.com/singapore/infected-after-holiday-to-europe-pregnant-mum-gives-birth-to-baby-with-covid-19-antibodies">told the Straits Times. </a> Ng-Chan wasn't COVID-19 positive during delivery. "My pregnancy and birth was smooth sailing despite being diagnosed with COVID-19 in my first trimester, which is the most unstable stage of the pregnancy. I'm very blessed to have Aldrin and he came out very healthy," Ng-Chan said. "I feel relieved my COVID-19 journey is finally over now."Her story adds a face to research suggesting that mother-to-infant COVID-19 transmission is rare, and that babies born to women who've had the illness may be somewhat protected, Dr. Jessica Madden, a pediatrician and neonatologist who serves as medical director of <a href="http://aeroflowbreastpumps.com/">Aeroflow Breastpumps, </a>told Insider. <h2>Some COVID-19 antibodies seem to cross the placenta </h2>Small studies have suggested that COVID-positive mothers pass on IgG antibodies — the type that indicate recovery — against the virus to their fetuses in utero. One <a href="https://jamanetwork.com/journals/jama/fullarticle/2763854">March paper</a> of six women who tested positive for the virus at delivery, for instance, found five had elevated levels of IgG antibodies even though none had COVID-19. All of the women wore masks, delivered their babies via C-section in negative-pressure isolation rooms, and were isolated from their children immediately after delivery — something <a href="https://www.businessinsider.com/new-moms-covid-very-low-risk-transmission-to-babies-study-2020-10">more recent research has suggested is unnecessary</a>.An <a href="https://pubmed.ncbi.nlm.nih.gov/33073377/">October case report</a> also describes an infant born to a mom with asymptomatic COVID-19 who had IgG antibodies but a negative COVID test, demonstrating "passive immunity" through the placenta, the authors write. In some ways, this is expected, since IgG antibodies against other bacteria and viruses are known to protect fetuses and newborns against infectious diseases, Madden told Insider. "This is the reason why certain vaccines, like pertussis and flu, are recommended during pregnancy," she said. "IgG antibodies increase in fetuses later in pregnancy, especially after the 36-week gestation mark." Still, more research is needed to understand how severity of illness affects antibody levels, how time of infection during pregnancy plays a role, and how strong and long-lasting babies' presumed immunity is.<a href="https://wwwnc.cdc.gov/eid/article/26/10/20-2328_article">One study out of Wuhan</a>, China, including 24 COVID-19-positive pregnant women suggested any immunity in newborns wanes quickly. What's more, Madden said, "we do not know if having COVID-19 prior to pregnancy will provide IgG immunity to fetuses who are conceived after a mother has already recovered from the virus." <h2>Breast milk has detectable antibodies too </h2>The breast milk of moms recently infected with COVID-19 is also believed to offer some protection to newborns. One <a style="font-size: 15px;" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7523143/">preprint study</a> in September showed that of 37 milk samples, none had detectable virus but all had antibodies thought to neutralize COVID-19. This too isn't entirely surprising since some breast milk antibodies are known to help protect babies from various diseases like measles while they're too young to receive a vaccine. Breastfeeding is also associated with a lower risk of conditions, including diabetes, asthma, sudden infant death syndrome, and some gastrointestinal illnesses. Those benefits outweigh the still-yet-unseen risks of breastfeeding with COVID-19, according to top health organizations like the Centers for Disease Control and Prevention, as long as new moms with the illness take precautions like wearing a mask and washing their hands and breasts before nursing. Read more:<ul class="read-more-links"><li><a href="https://www.insider.com/lab-grown-human-breast-milk-may-soon-be-option-biomilq-2020-2">Lab-made 'human' breast milk may soon be an option for parents who can't breastfeed but don't want to use formula</a></li><li><a href="https://www.businessinsider.com/what-pregnant-women-should-know-about-the-coronavirus-2020-3">What pregnant women should know about the coronavirus</a></li><li><a href="https://www.insider.com/breast-milk-may-help-identify-treatments-coronavirus-2020-5">New moms who've recovered from the coronavirus appear to have a 'strong immune response' to the disease in their breast milk</a></li><li><a href="https://www.businessinsider.com/pregnant-women-with-covid-19-more-likely-icu-cdc-2020-11">CDC: COVID-19 is more likely to be serious or deadly in pregnant women than other women of the same age</a></li></ul>

A woman said she gave birth to a baby with protective COVID-19 antibodies after contracting the virus during pregnancy

<ul class="summary-list"><li>A Florida baby may be first reported case to have COVID-19 antibodies from her mom's <keyword id="24209" type="PERSON" weightage="60" keywordseo="vaccine">vaccine</keyword>. </li><li>COVID-positive moms can pass antibodies to their babies in utero, too. </li><li>More research is needed on vaccines during <keyword id="6357793" type="UNKNOWN" weightage="60" keywordseo="pregnancy">pregnancy</keyword>. </li></ul>A baby girl born three weeks after her mom got the first dose of Moderna's COVID-19 vaccine has antibodies against the virus, a February <a href="https://www.medrxiv.org/content/10.1101/2021.02.03.21250579v1.full-text">pre-print paper reported</a>.After getting the shot, the mom, a healthcare worker in Florida, developed COVID-19 antibodies.Testing revealed those antibodies passed through the placenta to offer some potential protection to her future child, according to the authors at Florida Atlantic University. While past reports have shown how moms who've had COVID-19 can deliver babies with antibodies, the authors believe theirs is the first to record how vaccines during pregnancy may do the same. <h2>It's not clear how protective or long-lasting the antibodies are</h2>Authors Dr. Paul Gilbert and Dr. Chad Rudnick <a href="https://www.wptv.com/coronavirus/boca-raton-partially-vaccinated-woman-among-first-to-birth-baby-with-covid-antibodies">called their report a lucky "opportunity study,"</a> since they were able to find, and follow, a pregnant person who never tested positive for COVID but got the vaccine late in pregnancy and early in the rollout. When the baby - "a vigorous, healthy, full-term girl," according to the paper - was born, the doctors tested her cord blood for antibodies made from the vaccine, along with conducting other typical tests like for blood type.They were able to detect COVID-19 IgG antibodies (the type that indicate recovery), suggesting the baby has some protection against the virus, though how much or how long it lasts isn't clear. Future research should illuminate if there's an ideal time for a pregnant person to get vaccinated to maximize protection against the virus for her child. The authors say their results were expected based on what's known about how the vaccine, and others recommended during pregnancy like the flu vaccine, work.<h2>Past research has shown COVID-19 antibodies seem to cross the placenta </h2>Past studies have suggested that COVID-positive mothers can pass on IgG antibodies against the virus to their fetuses in utero. One <a href="https://jamanetwork.com/journals/jama/fullarticle/2763854">March 2020 paper</a> of six women who tested positive for the virus at delivery, for instance, found five had elevated levels of IgG antibodies even though none had COVID-19. An <a href="https://pubmed.ncbi.nlm.nih.gov/33073377/">October case report</a> also describes an infant born to a mom with asymptomatic COVID-19 who had IgG antibodies but a negative COVID test, demonstrating "passive immunity" through the placenta, the authors write. And, in November, a woman in Singapore who had COVID-19 in March 2020 <a href="https://www.businessinsider.com/singapore-woman-says-gave-birth-baby-with-covid-19-antibodies-2020-11">gave birth to a baby who has antibodies</a> that seem to be protective against the virus.Still, more research is needed to understand how severity of illness affects antibody levels, how time of infection during pregnancy plays a role, and how strong and long-lasting babies' presumed immunity is.Even more research is needed on <a href="https://www.businessinsider.com/should-pregnant-women-get-the-coronavirus-vaccine-2021-1">vaccinations in pregnant women</a>, who were excluded from the first clinical trials. While the shots are expected to be safe in pregnancy and no increase in complications have been reported, it will take time for thorough trial data to be collected and published. Until then, most professional and governmental organizations encourage pregnant people to make a decision that's right for them, based on their occupation, rates of transmission in their community, underlying health conditions, and other factors. Whatever the choice, "you should feel like your decision is respected," Dr. Jessica Madden, a pediatrician and neonatologist who serves as medical director of <a href="http://aeroflowbreastpumps.com/">Aeroflow Breastpumps, </a>previously <a href="https://www.businessinsider.com/should-pregnant-women-get-the-coronavirus-vaccine-2021-1">told Insider</a>.

A baby girl born to a partially vaccinated healthcare worker has COVID-19 antibodies

<ul class="summary-list"><li>Researchers at New York's Mount Sinai Hospital shared the results of their <a href="https://www.businessinsider.com/fda-approved-antibody-test-new-york-mount-sinai-2020-4">coronavirus antibody test</a> this week.</li><li>Almost every patient <a href="https://www.medrxiv.org/content/10.1101/2020.04.30.20085613v1.full.pdf">in the study</a> who tested positive for a <keyword id="1754604" type="PERSON" weightage="60" keywordseo="coronavirus">coronavirus</keyword> infection later tested positive for <keyword id="102007" type="TECHNOLOGY" weightage="60" keywordseo="Antibodies">antibodies</keyword>. That means false negatives are unlikely. </li><li>The hospital's director of clinical antibody testing said people should wait at least three weeks after their symptoms appear to get tested.</li><li>Patients who test positive likely have <keyword id="48619" type="PERSON" weightage="60" keywordseo="Immunity">immunity</keyword> to the virus, but questions linger about how long immunity will last.</li><li><a href="https://www.businessinsider.com/?hprecirc-bullet">Visit Business Insider's homepage for more stories</a>.</li></ul>As states and countries begin rolling back their lockdown restrictions, the results of widespread antibody testing may guide policies on whether schools can reopen or employees can return to work. But for some people who have received one of these tests, the <a href="https://www.businessinsider.com/coronavirus-symptoms-antibody-test-experience-2020-4">results have yielded more questions than answers</a>.Not all coronavirus antibody tests are the same. A team of Bay Area researchers recently <a href="https://covidtestingproject.org/">evaluated 14</a> on the market and found that only three were consistently reliable. Many of the tests produced false positives, meaning they signaled antibodies that a person didn't have. Plus, the results can be skewed based on when a person gets tested over the course of their illness, according to Ania Wajnberg, the director of clinical antibody testing at Mount Sinai Hospital in New York.Mount Sinai recently <a href="https://www.medrxiv.org/content/10.1101/2020.04.30.20085613v1.full.pdf">shared results</a> from <a href="https://www.businessinsider.com/fda-approved-antibody-test-new-york-mount-sinai-2020-4">its own antibody testing project</a>; the test was approved for clinical use by the US Food and Drug Administration in April. The findings showed that all but three of the 600-plus patients who had confirmed coronavirus cases tested positive for antibodies. Of more than 700 "suspected cases" — people who had coronavirus symptoms and lived with someone who tested positive or were told by a doctor that they likely had the virus — only 38% tested positive for antibodies. "I think there's a lot of people that think maybe they had it who didn't," Wajnberg said.Wajnberg offered advice about when to get tested and how to understand your results, based on her team's research.<h2>Certain tests could provide a better indication of long-term immunity</h2>Different tests <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7184973/">screen for different antibodies</a>. In Mount Sinai's case, the test looks for immunoglobulin G (IgG), the most common antibody found in blood and other body fluids. Other tests may screen for immunoglobulin M (IgM), which also circulates in the blood, or immunoglobulin A (IgA), an antibody found mainly in the respiratory and digestive tracts.In general, our bodies make IgM first in response to a viral infection. IgM is also associated with more acute viral infections, whereas IgG develops over a longer period of time. That means IgG is usually a better indicator of long-term immunity, but coronavirus patients who get tested shortly after developing symptoms may not have produced these antibodies yet. Scientists haven't determined if IgG antibodies confer immunity to this particular coronavirus, but the Mount Sinai researchers found that some level of protection is likely."Even though we don't know what's going on with this disease yet, if IgG confers immunity, that's the more important one that has implications for going back to work," Wajnberg said. The Bay Area researchers found that IgM tests produced more variable results than IgG tests, but the most consistent results came from testing for both antibodies at once. <h2>Wait 3 weeks to get an <keyword id="8966876" type="UNKNOWN" weightage="60" keywordseo="antibody-test">antibody test</keyword> if you're sick</h2>In the Mount Sinai study, 113 patients who were confirmed to have had the virus initially tested negative or "weakly positive" for antibodies; but when they were tested a second time, the majority tested positive for antibodies."In order to get the most meaningful results, the antibody tests are best if you wait a full three weeks after the start of your illness," Wajnberg said. "We even saw a small difference in our paper at 24 days versus 20 days."<div type="image" title="A scientist presents an antibody test for coronavirus in a laboratory of the Leibniz Institute of Photonic Technology (Leibniz IPHT) at the InfectoGnostics research campus in Jena, Germany, Friday, April 3, 2020. An international team of researchers with the participation of the Jena Leibniz Institute of Photonic Technology (Leibniz IPHT) has developed a rapid antibody test for the new coronavirus. By means of a blood sample, the test shows within ten minutes whether a person is acutely infected with the SARS-CoV-2 virus (IgM antibody) or already immune to it (IgG antibody). The strip test is manufactured by the diagnostics company Senova in Weimar and is already on the market. For most people, the new coronavirus causes only mild or moderate symptoms, such as fever and cough. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia. (AP Photo/Jens Meyer)" height="2403" width="3530" msid="75660588" hostid="261"></div>Patients may even want to wait four weeks to be safe, she added, but they shouldn't worry that the antibodies will disappear if they wait too long. For other coronaviruses like SARS and MERS, IgG antibodies seemed to <a href="https://www.medrxiv.org/content/10.1101/2020.04.14.20065771v1">peak within months of an infection</a> and last for a year or more."It is confusing for people because the viral tests are almost the opposite," Wajnberg said. "Those you want to do the minute you're not feeling well, because if you wait a month and you're feeling better, then the viral test might be negative."<h2>Patients should be symptom-free for 2 weeks</h2>Wajnberg recommended waiting two weeks after symptoms resolve to get an antibody test, though she said a patient who has been sick for a few weeks or more is likely to have developed antibodies by that point.<div type="image" title="Abbott COVID 19 Lab based antibody test 1" height="4480" width="6720" msid="75660593" hostid="261"></div>All patients involved in the Mount Sinai study were fully recovered — meaning they felt close to normal — by the time they received their antibody test."Not everybody was back to fully 100%, but I would say 90-plus," Wajnberg said.Around 19% of the patients tested positive for an active infection after their symptoms resolved. Wajnberg said it's possible that those patients were still contagious, but the more likely scenario is that they were shedding dead virus."What we're finding on the swab is not infectious live virus — it's dead virus or fragments of virus or even virus eaten up by your immune system," she said. According to Wajnberg, there's no reason to think that severe cases lead the body to produce more antibodies, since almost every patient in the Mount Sinai study had mild or moderate illnesses."In some viruses, the more severe you are, the higher antibodies you make. This study would suggest that that's not really the case," she said. "But we just don't know yet."The researchers also found that the duration of symptoms didn't influence a person's antibody response. Instead, Wajnberg said, the amount of antibodies a person produces may be related to innate differences in people's immune responses.<h2>Antibody tests could produce false negatives, but false positives are more likely</h2>With any coronavirus antibody test, researchers establish a minimum threshold of antibodies that are required for the results to come back positive. Wajnberg said the Mount Sinai team set a relatively high threshold to prevent people from testing positive with a low antibody count — which could perhaps lead people to false assumptions that they had immunity to the virus."The lower you set a threshold, the more likely you are to have false positives," she said. The study's results indicate that false negatives are very unlikely, though not impossible."With the numbers of people we're testing, even at a high sensitivity and specificity, you're still going to have false results — that's true of any test in the whole world," Wajnberg said. Researchers also still don't know the specific levels of antibodies required for a person to be fully immune; even patients with a lower threshold might still be protected. But there's still a lot to learn, Wajnberg said."It's super frustrating for people when they feel sure that they had [the coronavirus] and then the tests are not bearing that out," she said. "This is a crazy situation where we almost want to test everyone on Earth because we know that the tests aren't perfect."Read the original article on <a href="https://www.businessinsider.com/when-should-i-get-tested-for-coronavirus-antibodies-results-2020-5">Business Insider</a>

A researcher behind one of the most accurate antibody tests available explains when you should get tested — and how to understand your results

<ul class="summary-list"><li>A <a href="https://www.mdpi.com/2075-4418/10/7/453/htm">new review</a> ranked the top 13 <a href="https://www.businessinsider.com/companies-making-coronavirus-immunity-tests-serology-blood-2020-4">coronavirus antibody tests</a> out of more than 60 on the market.</li><li>The best tests had very few instances of false positive or false negative results.</li><li>But other tests had a wide range of accuracy levels, and some were less accurate than their manufacturers claimed.</li></ul>Hopes were high when the first <keyword id="1754604" type="PERSON" weightage="60" keywordseo="coronavirus">coronavirus</keyword> antibody tests debuted a few months ago. There was talk of issuing <keyword id="48619" type="PERSON" weightage="60" keywordseo="Immunity">immunity</keyword> passports based on the results. The tests were so coveted in the US that the Food and Drug Administration allowed some to go straight to market. Antibody tests detect our body's natural defense against a foreign pathogen. That means they can tell whether someone has ever been infected with COVID-19 — even if that person wasn't able to get tested initially. They can also give researchers a picture of how much the virus has spread within a population.But more than three months later, research shows many antibody tests don't offer consistently reliable results, and <a href="https://www.businessinsider.com/companies-making-coronavirus-immunity-tests-serology-blood-2020-4">some are far more accurate than others</a>. Plus, many mysteries remain when it comes to coronavirus immunity and how long it lasts.A <a href="https://www.mdpi.com/2075-4418/10/7/453/htm">new, independent review</a> published in the journal Diagnostics evaluated more than 60 serological (blood) antibody tests on the market. "Unfortunately, the results were not good," Ali Ardakani, the founder of life-science advisory group <a href="https://www.novateur.ca/covid-19">Novateur Ventures</a> and a co-author of the review, told Business Insider.The researchers found that most antibody tests didn't perform as well as their manufacturers claimed."We're six months in. There are hundreds of tests out there dispersing all sorts of information. Most of these tests are not even meeting their own specs when they're independently validated," Ardakani said.Scientists use two basic measures to determine the accuracy of an <keyword id="8966876" type="UNKNOWN" weightage="60" keywordseo="antibody-test">antibody test</keyword>: sensitivity and specificity. Sensitivity refers to how well a test detects antibodies when they're actually present (i.e. a true positive). Specificity refers to a test's ability to produce a true negative result. Ardakani's team found that most antibody tests had consistently high specificity, meaning false negatives weren't likely. But sensitivity varied significantly.Some antibody tests had 100% sensitivity, meaning all positive results should be accurate. Others had average sensitivity rates as low as 17%, according to raw data reviewed by Business Insider. A handful of individual tests showed 0% specificity, meaning any positive was false."The false positive is very serious," Ardakani said. "They're basically giving you the wrong sense of security."The researchers also highlighted the 13 highest-performing antibody tests on the market. A few FDA-approved tests — from Beijing Wantai Biological Pharmacy, Healgen, and Abbott — made the cut. However, the first FDA-approved antibody test, from the biotech company Cellex, did not. <h2>High-performing tests had very few false positives</h2>The top 13 antibody tests in the independent review had both high sensitivity and specificity. The rapid test from Healgen was one of the few tests with 100% sensitivity and 100% specificity — but those results were only for IgM antibodies.Coronavirus antibody tests target three types of antibodies: immunoglobulin M (IgM), immunoglobulin G (IgG), and immunoglobulin A. Our bodies typically make IgM first in response to a viral infection, so these antibody levels tend to peak earlier than the rest. IgG is the most common antibody found in blood and usually a better indicator of long-term immunity. Most coronavirus antibody tests focus on these two antibodies as opposed to IgA, which is found mainly in the respiratory and digestive tracts.The Healgen test for IgG antibodies had 96.7% sensitivity and 97.5% specificity. Both of the company's test results match the percentages <a href="https://www.fda.gov/medical-devices/emergency-situations-medical-devices/eua-authorized-serology-test-performance">listed on the FDA website</a>.The rapid test from Beijing Wantai Biological Pharmacy also performed well, with 97.5% sensitivity and 95.2% specificity, according to the review. The results <a href="https://www.fda.gov/medical-devices/emergency-situations-medical-devices/eua-authorized-serology-test-performance">listed on the FDA website</a> are slightly better, though: 100% sensitivity and 98.8% specificity.One of the most popular antibody tests in the US, the Abbott Architect test, had 97.2% sensitivity and 100% specificity when administered at least two weeks after a person's symptoms started, the review found. That means false positives were more likely than false negatives. But the results from the manufacturer indicate the opposite: that the test is 100% sensitive and 99.6% specific, according to <a href="https://www.fda.gov/medical-devices/emergency-situations-medical-devices/eua-authorized-serology-test-performance">the FDA</a>. As of Friday, Abbott has shipped around <a href="https://www.abbott.com/corpnewsroom/product-and-innovation/an-update-on-abbotts-work-on-COVID-19-testing.html">12.6 million antibody tests</a> across the the country.<div type="image" title="Abbott COVID 19 Lab based antibody test 1" height="4480" width="6720" msid="77128736" hostid="261"></div>Other tests that didn't rank highly had much wider discrepancies between their manufacturers' claims and the independent review. Cellex says its <a href="https://www.fda.gov/media/136625/download">rapid antibody test</a> is 93.8% sensitive. But the review found that the test's average sensitivity was closer to 72%.The review also found that Biomerica's rapid diagnostic test (which hasn't been approved by the FDA) had an average sensitivity as low as 45%. Allen Barbieri, vice chairman of the board at Biomerica, said in April that the test was more than 90% sensitive, <a href="https://www.technologyreview.com/2020/04/09/998974/immunity-passports-cornavirus-antibody-test-outside/">according to the MIT Technology Review</a>. <h2>Different tests may need to be administered at different times</h2>The FDA has approved nearby 30 coronavirus antibody tests through its expedited emergency-use process. The rush to develop and manufacture these tests may have come at the expense of accuracy, Ardakani said."A lot of these companies that have been developing these diagnostics were not in the business of developing clinical-grade medical diagnostics before," he said.Ardakani compared the process to building a car while driving it."Usually when you want to do proper development, you start with something called a target product profile —that means you say, this is my ideal diagnostic for this disease," he said. "Unfortunately, a guidance was not provided for any of these [tests] from any of the health authorities originally."But evaluating antibody tests, he added, can sometimes be like comparing apples to oranges. A test's performance depends on when it's administered and the type of antibody being measured.Since IgG and IgM levels are higher during the later stages of an infection, doctors usually advise patients to <a href="https://www.businessinsider.com/when-should-i-get-tested-for-coronavirus-antibodies-results-2020-5">wait a few weeks before getting an antibody test</a>.<div type="image" title="Coronavirus antibody studies abound" height="1687" width="2531" msid="77128743" hostid="261"></div>German researchers <a href="https://pubmed.ncbi.nlm.nih.gov/32235945/">determined in April</a> that coronavirus patients typically develop IgM and IgG antibodies after five to 14 days. Half the patients in that study had detectable levels of antibodies in their blood after one week of symptoms. A <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7236821/">May study</a> from Chinese researchers also found that IgM and IgG antibodies were detectable after five days. After 32 days of symptoms, all patients in that study had developed antibodies.<h2>How long do antibodies last?</h2>People who suspect they had COVID-19 might not want to wait too long to get an antibody test. A <a href="https://www.medrxiv.org/content/10.1101/2020.07.09.20148429v1">July study</a> from UK researchers — though still awaiting peer review — showed that coronavirus antibodies may disappear <a href="https://www.businessinsider.com/coronavirus-new-uk-study-shows-antibodies-fade-after-three-weeks-2020-7">less than three months</a> after symptoms arrive. IgG antibodies may be detectable for longer than IgM — around 49 days compared to roughly 35 days — according to <a href="https://www.medrxiv.org/content/10.1101/2020.03.24.20042382v1">a March study</a> that's also not yet peer reviewed.There's also recent evidence that patients with severe COVID-19 cases may have <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7236821/">significantly higher levels of antibodies</a> than people with mild cases. One study even found that asymptomatic coronavirus patients <a href="https://www.nature.com/articles/s41591-020-0965-6">may test negative for antibodies</a> during the early stages of recovery. That means any antibody test results should be taken with a grain of salt. Those receiving them should also inquire about the maker."A lot of times you cannot translate what you did in your perfect lab, the way you perfectly performed the procedure, when you give it to a nurse that's rushed in front of a patient in a busy hospital," Ardakani said. "We can't even replicate these tests back to back."

A new study evaluated the accuracy of more than 60 coronavirus antibody tests. 13 were a cut above the rest.

By H S Rao London, Jun 26 () The timing of COVID-19 antibody test is critical to detect the infection in a patient, scientists have found in the most comprehensive review of the coronavirus testing to date. The researchers examined all available test accuracy evidence for antibody tests published up to the end of April. By combining data from many studies, they have shown that the tests are not accurate enough to confirm whether someone has the COVID-19 virus if used in the first two weeks after the symptoms appear. The researchers found that tests were only likely to be useful in detecting previous SARS-CoV-2 infection if used at least 14 days after the onset of symptoms, but say that studies show that the tests will miss 1 in 10 cases of COVID-19. However, they caution over reliance on this figure, as the studies were small, poorly reported and done in select patient groups. The researchers also fear accuracy will be lower when tests are used in the community, as the tests have mostly been evaluated in hospitalised patients – making it unclear whether they can detect lower antibody levels associated with milder and asymptomatic COVID-19 disease. Led by experts at the University of Birmingham, a group of researchers drawn from universities around the globe have published their findings in the Cochrane Database of Systematic Reviews. "We've analysed all available data from around the world and discovered clear patterns telling is that timing is vital in using these tests. Use them at the wrong time and they don't work," said Jon Deeks, professor of Biostatistics and head of the Test Evaluation Research Group at the University of Birmingham. "There are promising tests, but there isn't enough evidence to be able to identify the best tests yet, and we need to continue analysing data as it becomes available – particularly from non-clinical settings where individuals are displaying less severe symptoms, and following people over longer time periods," Deeks said. The immune system of people who have COVID-19 responds to infection by developing cells that can attack the virus (antibodies) in their blood. Tests to detect antibodies in peoples' blood could show whether they currently have COVID-19 or have had it previously. The body produces three classes of antibody - IgA, IgG and IgM. Most antibody tests measure both IgG and IgM, but some measure a single antibody or combinations of the three antibodies. Levels of antibodies rise and fall at different times after infection, with the IgG antibody usually highest a few weeks after infection. Some tests use venous blood and specialist laboratory equipment, whilst others use finger prick blood samples on disposable devices similar to pregnancy tests, which can be performed in laboratories, hospitals or at home. Researchers searched through over 11,000 publications on COVID-19 available at the end of April 2020, and identified 54 relevant studies from Asia, Europe, and the USA – that measured the accuracy of antibody tests used to detect current or past COVID-19 infection - whether in hospital or the community. In total these studies reported nearly 16,000 test results. "Accurate testing is vital – these tests may help identify COVID-19 in people who have had symptoms for two or more weeks but never had a swab test, and identifying how many have had the SARS-CoV-2 infection to assess disease spread and the need for public health interventions," the researchers noted. "In time, we will learn whether having previously had the infection provides individuals with immunity to future infection, which will indicate the personal value of having this test," they said. HS MRJ MRJ

Antibody tests may help detect COVID-19 infection if used at right time: scientists

A team of US researchers have developed a simple, glucose-meter-based test that can be used to accurately monitor our own antibody levels to fight SARS-CoV-2, the virus causing Covid-19. Over-the-counter Covid tests can quickly show whether a person is infected with SARS-CoV-2. But if you have a positive result, there's no equivalent at-home test to assess how long you're protected against reinfection, said researchers from <keyword id="210763" type="General" weightage="80" keywordseo="johns-hopkins-university" source="Orion">Johns Hopkins University</keyword>, <keyword id="54274" type="General" weightage="80" keywordseo="mit" source="Orion">MIT</keyword> and <keyword id="97117" type="General" weightage="80" keywordseo="harvard-university" source="Orion">Harvard University</keyword>. It is because vaccines against Covid infection can guard against future infections for a while, but it's unclear exactly how long that protection lasts. A good indication of immune protection is a person's level of antibodies, but the gold standard measurement -- the enzyme-linked immunosorbent assay (<keyword id="164124" type="General" weightage="80" keywordseo="elisa" source="Orion">ELISA</keyword>) -- requires expensive equipment and specialised technicians. The new readily available glucose meter, described in the <keyword id="3653366" type="General" weightage="80" keywordseo="journal-of-the-american-chemical-society" source="Orion">Journal of the American Chemical Society</keyword>, are easy to use and can be integrated with remote clinical services. In the study the team wanted to see whether producing a fusion protein consisting of both invertase and a detection antibody would work in an assay that would allow SARS-CoV-2 antibody levels to be read with a glucose meter. The researchers designed and produced a novel fusion protein containing both invertase and a mouse antibody that binds to human immunoglobulin (IgG) antibodies. They showed that the fusion protein bound to human IgGs and successfully produced glucose from sucrose. Next, the team made test strips with the SARS-CoV-2 spike protein on them. When dipped in Covid-19 patient samples, the patients' SARS-CoV-2 antibodies bound to the spike protein. Adding the invertase/IgG fusion protein, then sucrose, led to the production of glucose, which could be detected by a glucose meter. They validated the test by performing the analysis with glucose meters on a variety of patient samples, and found that the new assay worked as well as four different ELISAs. The researchers said that the method can also be adapted to test for SARS-CoV-2 variants and other infectious diseases. ALSO SEE: <a target="_blank" class="c-link c-message_attachment__title_link" href="https://www.businessinsider.in/science/health/news/4-useless-supplements-youre-likely-already-getting-enough-of-through-your-diet-according-to-nutrition-experts/articleshow/92304572.cms">4 useless supplements you're likely already getting enough of through your diet, according to nutrition experts</a> <a target="_blank" class="c-link c-message_attachment__title_link" href="https://www.businessinsider.in/science/health/news/as-a-widow-and-a-mom-im-still-figuring-out-how-to-celebrate-fathers-day-without-my-husband-around/articleshow/92318459.cms">As a widow and a mom, I'm still figuring out how to celebrate Father's Day without my husband around</a>

A simple glucose meter test can help you accurately monitor Covid-19 antibodies

Beijing, Jun 18 () COVID-19 patients who do not show any symptoms of the disease may have a weaker immune response to the virus, according to a new study which highlights the risks of using 'immunity passports' to certify that a person has recovered from COVID-19, and is fit for travel and work. The research, published in the journal Nature Medicine, presents an analysis of the clinical and immunological manifestations of 37 asymptomatic patients infected with the novel coronavirus, SARS-CoV-2. It found that these patients had an average duration of viral shedding of 19 days, compared with 14 days in another group of 37 patients who showed symptoms of the disease. According to the scientists from the Chongqing Medical University in China, most people infected with SARS-CoV-2 experience a mild to severe respiratory illness with symptoms that include fever, cough, and shortness of breath that may appear 2–14 days after exposure. However, they said several who test positive for the infection may either experience minor symptoms or be asymptomatic. In the study, the researchers studied 37 asymptomatic people diagnosed with SARS-CoV-2 infection from the Wanzhou district in China, before 10 April 2020. Of these asymptomatic patients from a group of 178 people with SARS-CoV-2 infection, 22 were female and 15 male, with ages ranging from 8 to 75 years, the scientists said. "In comparison to symptomatic patients, the asymptomatic group had a significantly longer duration of viral shedding, with a viral shedding time of 19 days," they wrote in the study. According to the study, the levels of virus-specific immune system molecules called IgG antibodies were significantly lower in the asymptomatic group than in the symptomatic group during the acute phase of infection when the virus could be detected in the respiratory tract. Eight weeks after the patients were discharged from the hospital, the researchers said the levels of neutralising antibodies decreased in more than 8o per cent of asymptomatic patients, compared with about 62 per cent of symptomatic patients. They added that the asymptomatic patients also had lower levels of 18 pro- and anti-inflammatory cell-cell signalling proteins called cytokines. Based on these observations, the scientists believe that the asymptomatic patients may have had a weaker immune response to SARS-CoV-2 infection. The IgG antibody levels in the patients also began to diminish within three months of infection in a large proportion of the asymptomatic patients, the study noted. This finding, along with previous analyses of neutralising antibodies in patients recovering from COVID-19, highlights the potential risks of using 'immunity passports,' and supports the continuation of public-health interventions and widespread testing, the researchers said. They believe that further research in larger groups of symptomatic and asymptomatic patients is urgently needed to determine the duration of antibody-based immunity. VIS VIS VIS

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