Thought of the Day - June 11 - Why Are We Not Doing Antibody Testing?

Following on from my previous note there is a whole other body of tests that detect whether your body has produced a response-protein to an antigen, in this case to SARS-COV-2. These are known as antibody tests. Antibody testing for SARS-COV-2 is widely used around the world but is still yet to be introduced here in Canada. These are my thoughts as to why this is:

1. Value: There is limited value in introducing antibody testing when almost none of the populous has been exposed;

2. Immunity: There was a train of thought that said if we are using positive antibody test results as a proxy for immunity we need to know more about whether the presence of antibodies means continued immunity;

3. Accuracy: There were a number of products whose accuracy (sensitivity - able to provide true positives, and specificity - able to provide true negatives) was suspect;

4. Product Supply: Tests needed to be certified and the supply for Canada had to be secured;

5. Testing: In general this is a blood test, and a number of early tests were not easy to administer;

6. Results: What to do with the results?

These were all legitimate concerns in the early days (read: back in March).

But where are we today?

1. Value: We know that a cross-section of the Canadian population has now been exposed to SARS-COV-2 and have antibodies. I estimate between 3-4%, and hey you can't say I am wrong. But this is the very reason that we need to introduce the test, we really don't know;

2. Immunity: A growing body of evidence is saying that the presence of antibodies does mean you are immune (of course the question of how long cannot be answered as we have only been living with SARS-COV-2 for six months now but waiting for years to confirm that immunity lasts for years is pretty silly);

3. Accuracy: The accuracy of these tests (including administration procedures) is now well known, and though not ideal - some are suggesting an accuracy of 95% - this is far better than we have by any other method;

4. Product Supply: While it would be ideal if all of Canada could use the same test (both from comparability and theoretically for cost reduction), this is also really a moot point. Moreover, the cost of the tests is in the tens of dollars;

5. Testing: Many tests are no more difficult to administer than diabetic blood tests, they can be performed by the general public;

6. Results: This is still really the main issue. Our policymakers have not decided whether the public deserves to know. Confirming one person is immune and another is not opens up a political can of worms in this "PC" world and thus they have not sanctioned a formal approval process.

It is encouraging to see that places like Toronto are at least conducting random public screening to help address the first point, gaining a better understanding of our true infection rates. But also let's hope we can move rapidly to the next step allowing individuals to know if we have had COVID-19. Simply banning the sale of the antibody testing products to the Canadian public, by saying it is our own interest, is getting pretty long in the tooth. Actually, it can be said the delay is putting the lives of our most vulnerable in more danger as we continue to blindly rely on inaccurate antigen testing and fall back on crude symptom-testing methods. Indeed the lack of antigen testing ultimately prevents us from embracing the "New Normal".

Cheers

Cliff