Lateral flow tests less effective for Omicron, US health chiefs rule

Covid lateral flows ARE less effective at spotting Omicron, US officials fearbut UK health chiefs insist there’s still no proof the variant can evade rapid swabs

  • FDA says new data using live Omicron shows lateral flow tests are less accurate
  • Finding is at odds with UKHSA data which shows the tests still detect Omicron
  • Conflicting data comes as Brits are urged to take a test before meeting others
  • Covid lateral flow tests may be less effective at detecting 奥米克戎, US health chiefs have warned.

    The Food and Drug Administration (食品药品监督管理局) said new laboratory findings indicated the rapid kits — which give results in as little as 15 minutes — could still spot the highly-infectious variant.

    But bosses warned they may have reduced sensitivity, meaning they could wrongly tell more infected people they are free of the virus.

    Doubts over the tests come as ministers and health officials in the UK urge people to take a lateral flow test before going out to meet people in an attempt to reduce the chances of people unknowingly passing the virus on to others.

    Scores of Britons have complained over the Christmas period that they received a negative lateral flow result only later to test PCR positive.

    But the UK Health Security Agency (UKHSA) has insisted that data shows lateral flow tests are just effective at detecting Omicron.

    Lateral flow test kits, like the one pictured above are a cornerstone of the Westminster Government's plans to keep venues like nightclubs and pubs open with ministers urging revelers to take one before heading out to meet others in case they have Covid

    Lateral flow test kits, like the one pictured above are a cornerstone of the Westminster Government’s plans to keep venues like nightclubs and pubs open with ministers urging revelers to take one before heading out to meet others in case they have Covid

    The number of lateral flow tests taken in England has risen significantly since the start if December with the 1million mark being breached multiple times as officials urged people to take a test before meeting others

    The number of lateral flow tests taken in England has risen significantly since the start if December with the 1million mark being breached multiple times as officials urged people to take a test before meeting others

    A woman named Angela was one of numerous Britons who have detailed a case where a family member tested negative on a lateral flow test but later positive on a PCR test

    A woman named Angela was one of numerous Britons who have detailed a case where a family member tested negative on a lateral flow test but later positive on a PCR test

    Rose Bateman was another, who found herself with a negative result using a latera flow test for Covid but tested positive using a PCR tests later on the same day

    Rose Bateman was another, who found herself with a negative result using a latera flow test for Covid but tested positive using a PCR tests later on the same day

    Roy from the Hampshire and Surrey Border area claimed to have two family members receive the opposite result of their lateral flow test when later taking a PCR test

    Roy from the Hampshire and Surrey Border area claimed to have two family members receive the opposite result of their lateral flow test when later taking a PCR test

    Home delivery rapid tests are unavailable for third dayas ministers say take a lateral flow before going out

    Pharmacists have called for urgent action to improve the supply of lateral flow tests as they say they are being forced to turn people empty-handed.

    The Government has advised people to take lateral flow tests before they socialise after confirming on Monday that no new Covid restrictions would be brought in for New Year’s Eve festivities.

    But the Association of Independent Multiple Pharmacies says people are being turned away every five minutes due to ‘patchysupply and said it was frustrating that chemists it represented were having to wait several days for each delivery.

    The UK Health Security Agency said it was facing ‘unprecedented demandfor the tests but insisted it had doubled its capacity since mid December.

    It comes as lateral flow tests are unavailable for home delivery for a third day running meaning some families will be unable to test ahead of New Year’s Eve celebrations this weekend.

    The Government’s website states it is not possible to order lateral flow testing kits for home delivery with a message stating: '抱歉, there are no home delivery slots left for rapid lateral flow tests right now.

    ‘You may still be able to pick up rapid lateral flow tests from a pharmacy or collection point, where these are available. Only pick up tests if you do not have symptoms.

    Pharmacies across the country have reported shortages of LFTs and many are unable to replenish their kits as the supply chain has been affected by Christmas and New Year holidays.

    Some pharmacies reported they have not had stock since last Monday and it could take three days for new supplies to arrive.

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    The FDA’s statement was based on early data from new laboratory tests involving live samples of the the Omicron virus.

    Like the UKHSA, the US agency has been analysing whether lateral flows are just as effective at detecting new Covid variants.

    The FDA previously tested the accuracy of the tests using samples of dead Omicron virus, and found they were just as effective.

    But now lab tests using live samples of the virus have raised fresh doubts about their accuracy.

    ‘Early data suggests that antigen tests do detect the Omicron variant but may have reduced sensitivity,’ 他们说.

    然而, the FDA is still advising people to use lateral flow tests, saying the findings are still at an early stage.

    ‘It is important to note that these laboratory data are not a replacement for clinical study evaluations using patient samples with live virus, which are ongoing,’ 它说.

    ‘The FDA continues to authorize the use of these tests as directed in the authorized labeling and individuals should continue to use them in accordance with the instructions included with the tests.

    No data on how less sensitive lateral flow tests may be at detecting Omicron or how many samples of the virus were tested was detailed in the FDA announcement.

    Lateral flow tests are a key cornerstone of the UK Government’s plans to keep the hospitality sector open in England over the festive period with officials urging people to take a test before heading out to meet others.

    But numerous Britons have cast doubts over if lateral flow tests are accurate enough in recent days following officials advocating for their regular use over the festive period.

    One mother described how her son had received five negative lateral flow test but later tested positive on a PCR test.

    ‘My son has had a positive Covid PCR test, despite five lateral flow tests showing he’s negative. He has all the symptoms of Omicron and feels pretty roughhe’s 25 and super fit,’ 她说.

    Roy, 从汉普郡, also said he had two cases in his family where lateral flow tests had not been accurate.

    ‘So in the last few days my son had a negative lateral flow test but a positive PCR as he felt a bit chesty. My son-in-law had a positive natural flow test but a negative PCR,’ 他说.

    UK Health Security Agency (UKHSA) data showed 129,471 people tested positive in England over the last 24 小时, 向上 43 per cent on last week's figure of 90,629 — which included case numbers for the other home nations as well

    UK Health Security Agency (UKHSA) data showed 129,471 people tested positive in England over the last 24 小时, 向上 43 per cent on last week’s figure of 90,629 — which included case numbers for the other home nations as well

    How to do a rapid lateral flow test

    Rapid lateral flow tests are for people who do not have Covid symptoms, such as a high temperature, a cough or a loss or change to smell or taste.

    The tests give a quick result using a device similar to a pregnancy test.

    People with Covid symptoms should do a PCR test.

    Before doing a rapid lateral flow test the NHS advises:

    • try not to eat, 喝, smoke or vape 30 minutes before doing the test as this may affect the result
    • read the instructions carefully
    • clean the surface you’re putting the test on
    • check nothing in the test kit is damaged or broken
    • start the test within 30 minutes of opening the test kit

    If your test requires a throat swab:

    • open your mouth wide and rub the swab over your tonsils (or where they would have been)
    • avoid the end of the swab touching your teeth, tongue and gums
    • put the same swab inside your nose (关于 2.5 cm up or until you feel some resistance)

    If your test requires a nose swab only:

    • put the swab inside your nose (关于 2.5 cm up)

    Completing the test:

    • put the end of the swab into the tube so it’s in the liquid
    • squeeze the liquid from the tube onto the test strip
    • check the waiting time in the instructions that came with your test kit
    • wait for the time shown in your test kit instructions
    • read your result
    • report your result on the Government website
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    And single mother Rose Bateman also detailed her experience: ‘I tested negative on a lateral flow the morning I took my positive PCR test two hours later, as I had some cold symptoms.

    When contacted by MailOnline about the FDA’s findings, UKHSA referred to data published earlier this month demonstrating that lateral flow tests were just as accurate at detecting Omicron as they were with previous variants.

    In its tests the UKHSA used the five lateral flow testing brands dished out by the NHS on samples from patients infected with Omicron.

    All of the tests showed a positive result for each patient, even when their sample was diluted, showing the devices have ‘a comparable sensitivity to that observed for previous strains’ Covid的, the UKHSA said.

    然而, 当时, the UKHSA said it was monitoring how well the tests perform in the real world to ensure their sensitivity is not ‘significantly reducedwhen people swab themselves.

    The tests, which can tell if someone is infected in as little as 15 分钟, report positive results by detecting the virus’s nucleocapsid protein.

    But this part of Omicron’s cell has four mutations, which has raised concerns that the test could be less effective.

    Fears about the accuracy of lateral flow tests and Omicron were first raised by South African experts, where Omicron was first identified.

    Dr Angelique Coetzee, chair of the South African Medical Association, told MPs on the Science and Technology Committee: ‘The rapid test still showing false negatives in the early period.

    ‘We do have patients that waited a week and still have a headache and then they do PCR and it’s positive.

    But despite being urged to take lateral flow tests before meeting up Britons are having increasing trouble securing a supply as the number of kits available dwindles.

    今天, pharmacists called for urgent action to improve the supply of lateral flow tests, stating they are being forced to turn people away empty-handed.

    The Association of Independent Multiple Pharmacies says people are being turned away every five minutes due to ‘patchysupply.

    And it said it was frustrating that chemists it represented were having to wait several days for each delivery.

    The UK Health Security Agency said it was facing ‘unprecedented demandfor the tests but insisted it had doubled its capacity since mid December.








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