Yesterday, President Cuomo mentioned serological testing, which could end this crisis sooner than we think. Donna and I both had a wicked run with a virus in January with symptoms that sound similar to the Covid-19, and even if it was only a cousin, maybe the antibodies will ward off the real thing. If so, I’d like to get back to work!
Just how many people actually have Covid-19? How long will it be before we can safely begin to ease social distancing? And is this a one-off crisis or are we now facing the threat of repeated waves of coronavirus pandemics on an annual basis?
These are all questions to which scientists around the globe are racing to answer through serological testing – detecting tell-tale antibodies in the blood to identify the real number of people in a population who have ever come in contact with the virus. Over the coming months, the results will determine everything from how long society’s shutdown needs to be, to evaluating the effectiveness of the new vaccines on the horizon.
Right now, the NHS tests for Sars-CoV-2 – the virus that causes Covid-19 – through a diagnostic technique called polymerase chain reaction (PCR) which detects the virus’ genetic material in oral or nasal swabs. It’s highly effective, but it only returns a positive result when the virus is still present in the body.
Serological testing will tell us how many people crossed paths with the coronavirus weeks or even months ago – sometimes without knowing – a figure which epidemiologists modelling the spread of Covid-19, and governments need to know to make accurate public health decisions.
“You’ll have heard [the UK’s chief scientific advisor] Patrick Vallance talk about herd immunity as a useful outcome if enough people have had the infection,” says Andrew Freedman, consultant in infectious diseases at Cardiff University. “That’s something you can determine if you do serologic testing on enough representative people across the country. If you find that 60 per cent or more of the population have got antibodies to the virus, so they’ve already had the infection, this would tell you that herd immunity might be successful and it’ll stop spreading. So then the government could stop the social distancing and isolation precautions at the moment.”
As the wait for new drugs for Covid-19 goes on, serological testing is also likely to be used to identify people who have recovered from the virus, who may be asked to donate their blood as a form of emergency treatment for elderly or vulnerable people that are acutely ill. This is a treatment idea for virulent infections which dates back to the Spanish influenza, more than a century ago.
“Serology can be used to identify people with high levels of neutralising antibodies that can kill the virus,” says Theel. “Their plasma would be tested, collected, screened for HIV and hepatitis, and then administered to ill patients. The idea being these antibodies could quickly activate and kill the virus in those sick people.”
Read the full article here:
I hope you and Donna are feeling better, Jim! Be well.
We’re all good now – watching Day After Tomorrow with Kayla the New Yorker!
President Cuomo? Wishful thinking?
He looks like he’s thinking about it. Newsom too.
Newsom has always been the CA Democratic heir apparent for a Presidential run. They were hoping to catch lightning in a bottle with K Harris, but the old guard has been grooming Newsom for an eventual run ever since he became mayor of SF.
From the wsj:
LONDON—With a vaccine against the new coronavirus many months away and no known effective drug treatments yet, governments around the world are searching for the next best thing: a test to see if people are immune to the virus.
In Britain, the government said Wednesday it is trialing personal blood-testing kits that it hopes to distribute as soon as next week. The test—if it functions—could clear the way for people who have caught and recovered from Covid-19 to return to work or volunteer to help others, potentially easing the disruption caused by the pandemic.
Across the world, laboratories and diagnostics companies are racing to fine-tune a cheap, portable, mass-testing device that can quickly show if a person has acquired immunity to the virus. The U.S. Centers for Disease Control and Prevention has said it is also working on its own antibody test for the virus.
These tests are different to the throat or nose swabs that check whether someone is ill with the coronavirus and can take 24 hours or more to process, according to the U.K. government.
The U.K. has purchased 3.5 million antibody tests, which look similar to pregnancy tests and require a drop of blood, Health Secretary Matt Hancock said.
The British government is evaluating several versions of these tests in the coming days in a laboratory in Oxford, Sharon Peacock, the director of the U.K. National Infection Service said Wednesday.
If successful, tests would be available to the public soon, either delivered to peoples’ homes by Amazon. com or stocked in local pharmacies. Ms. Peacock said health workers would likely get priority access to the tests.
It isn’t yet clear how people who self-administer the test can demonstrate their immunity and gain approval to move freely in public. Nor is it clear how long immunity lasts after an individual contracts coronavirus.
A spokesman for the National Infection Service declined to comment on who was making the tests, but Ms. Peacock said they would be purchased from Southeast Asia.
“The one thing that’s worse than no test is a bad test,” said Chris Whitty, the U.K.’s chief medical officer. “This is not something we’ll be ordering on the internet next week.”
The British Department of Health declined to elaborate on how the test would be rolled out should it go ahead with the plan.
“It is going to give us a crude yes or no, have you have encountered the virus or not,” said David Wraith, director of the Institute of Immunology and Immunotherapy at the University of Birmingham. “That is a good measure of protection.”
These tests require a prick of blood from a finger, much like a diabetic test and can return a result quickly, Ms. Peacock said. Last week British Prime Minister Boris Johnson said that the government was in negotiations to buy the tests “because obviously it has the potential to be a total game-changer.”
The U.K. announced a nationwide lockdown on Monday that limits residents to leaving their homes only under specific, essential circumstances. The country had 8,077 confirmed coronavirus cases as of Tuesday.
Still, there is skepticism among experts that a reliable at-home test could be developed so quickly.
“As far as I know there’s no home-monitoring test that anyone has evaluated in a meaningful manner,” said Rangarajan Sampath, chief scientific officer at the Foundation for Innovative New Diagnostics, a Switzerland-based nonprofit that has been closely tracking diagnostic research efforts for Covid-19. “I’m afraid this creates a false sense of ‘We are doing something’ hope.”
Antibody tests—which measure whether the body’s immune system has produced antibodies to counter the presence of the disease—are more challenging to develop than laboratory tests that diagnose a disease from the presence of viral genetic material.
“If you look at how many truly available home tests there are for infectious diseases, you can count them on one hand,” said Dr. Sampath. “That comes from the underlying complexity.”
Another concern with at-home testing is that consumers may not use them appropriately, or know what to do with the results. The earliest that antibodies are detectable in blood is three or four days after the onset of symptoms, according to Dr. Sampath. That means that if people test themselves as soon as they have symptoms they may wrongly assume they don’t have Covid-19.