Media reports about Covid 19 antibody testing and tests for current infection can be very hard to assimilate. In response to many enquiries, in this blog post I will try to provide the key information as it is currently believed to be. The scientific community are working very hard to learn more about this virus and what it means for us. That means that, almost inevitably, what I write here will be outdated within hours or days.
There are two different types of testing. The first is for current infection.The second is Covid 19 antibody testing which is used to demonstrate the presence of a substance known as IgG which you develop in response to a given infection. It is becoming increasingly obvious that many people contact and fight off this virus without recognising that they are “ill”.
The NHS provides tests for those thought to have a current infection. In England and Wales anyone who has symptoms of coronavirus, whatever their age, can ask for an NHS funded test. Some hospitals are offering testing for current infection to anyone who is admitted and stays overnight in hospital, including maternity patients. More information is available here, including how to book a test.
Covid 19 antibody testing is not yet widely available, other than for some groups of key workers. When you meet an infection, your body produces proteins called immunoglobulins to protect you. Initially IgM is produced as your body works to overcome it. In time, you then produce IgG, specific to that infection. At the moment you can only get the Covid 19 IgG by meeting the active infection. Immunisation is used to provoke your body to make a particular IgG. This principle is widely used to give you protection without becoming ill. Hence the drive to try to produce a Covid 19 vaccine (as yet still a work in progress in the labs) so that you can develop IgG without the risk of a major clinical infection.
Various antibody tests are being advertised. Some require a standard blood test sample, usually taken from the arm, others offer you a DIY finger prick option. There has been debate in scientific circles about the reliability finger prick sample testing. In response to requests from clients I am now able to offer the Abbott test. The version I am using requires a standard blood test sample. I am only able to test adults, in accordance with my registration with the Care Quality Commission (CQC) .
People produce IgG antibodies at different rates. It is not yet know what the optimal time is for testing, but it is thought to be at least 14 days after possible contact with the virus. If you have Covid19 IgG, it means that your body has met and responded to the infection (successfully, obviously, if you are well now!). If Covid 19 IgG is reported it is certain that you have met and dealt with it. No “false positives” are reported with this particular test according to current information. I will only test people who are able to confirm that they, and their entire household, have been symptom free for at least 14 days.
As with IgG to other infections, it is believed that the level of antibodies may drop over time. This may mean that the antibodies cannot be detected by this test. This means that “false negative” results are possible – meaning that you have met it/been infected and mounted a response, but we can’t prove that. Science does not yet know what having detectable IgG means in the longterm. With most infections that have been studied, once you have produced IgG you are then “immune” and cannot be reinfected.
Having antibodies in your blood would not prevent you passing on infection through touch, so hand washing remains very important. Antibodies can only deal with what gets inside your body. If you touch a surface and get virus on your hand, you could then touch it onto someone else. How likely this is to cause infection is being researched. It is known that most infection is spread by droplets from inside the body of someone who has an active infection (before they produce IgG – so through coughing, spit etc.
If you are interested in being tested the cost is currently £65 per person. Visit charge varies according to your location. Call or message me to learn more.