Immunity certification gets closer

As we reported last week, the idea of immunity certificates has got closer to adoption.

Britain could roll out coronavirus ‘immunity wristbands or certificates’ for people who have already fought off the deadly infection under antibody testing scheme. Britons who have already have fought off the Covid19 could be given ‘immunity wristbands’ or “certificates” or the equivalent as a phone app. The difficulty with low tech immunity wristbands is the very high risk of forgeries being sold on the black market to allow self-employed to get back to work. Hi-tech wristbands with ID Chips embedded or phone apps utilising QR codes which allow officials to decode the QR code and see who the QR Code was issued to are not thought to be as open to fraud.

Health Secretary  Matt Hancock admitted Number 10 was looking at the move at a Downing Street press conference tonight when he said “We are looking at introducing something like an immunity certificate or a wristband that says “I’ve had it and I’m immune and I can’t pass it on and I’m highly unlikely to catch it”.

Antibody tests are the only ones that can tell if someone has ever caught the deadly infection, and the so-called “murky evidence” about whether immunity prevents a second reinfection  is due to overseas report, mainly from China and Japan that a handful of patients who tested positive subsequently caught corona or who tested as positive, then were released from quarantine as clear, subsequently tested as positive again. One set of about a hundred tests from China showed that around 14 per cent of coronavirus patients tested positive a second time. The vast majority of researchers and immunologists believe this is down to unreliable tests or people bribing their way out of quarantine and are optimistic that people who have had Covid19 are subsequently can become immune to the virus, and can’t be infectious. Most scientists believe the evidence for immunity is convincing and some even claim that it could be life-long as was the case with Spanish Flu.

An antibody test is one which tests whether someone’s immune system is equipped to fight a specific disease or infection. For example, if someone catches COVID-19, they will develop COVID-19 antibodies and store versions of these antibodies in the immune system so that if it comes into contact with that same virus again it will be able to fight it off straight away and the virus can’t get a hold to make that person ill or infectious. To test for these antibodies, medics or scientists can take a fluid sample from someone – usually blood – and mix it with part of the virus to see if there is a reaction between the two.  If there is a reaction, it means someone has the antibodies and their body knows how to fight off the infection – they are immune. If there is no reaction it means they have not had it yet.

This compares with the PCR Test (a polymerase chain reaction test or infection test) which aims to pick up on active viruses currently in the bloodstream. A PCR test works by a sample of someone’s genetic material – their RNA – being taken to lab and worked up in a full map of their DNA at the time of the test. This DNA can then be scanned to find evidence of the virus’s DNA, which will be embroiled with the patient’s own if they are infected at the time. The PCR test is more reliable but takes longer, while the antibody test is faster but more likely to produce an inaccurate result. There is also an Antigens Test which tests for antigens which are parts of a virus that trigger the immune system’s response to fight the infection, and can show up in blood before antibodies are made. The key advantage of antigen tests is that it can take several days for the immune system to develop enough antibodies to be picked up by a test, whereas antigens can be seen almost immediately after infection. Antigen tests are used to diagnose whether the patient has flu or Covid19 and is carried out by using swabs.

Leave a Reply