Updated: Aug 14, 2020
This is a summary of the interview I did with Patrick Bouic, professor of immunology at Synexa Life Sciences about the science and biology of getting COVID19 twice.
The full interviews with Patrick & Melina are up on my IGTV on @livingcoronapositive.
For the interview with Melina, click here.
For the interview with Patrick, click here.
I managed to pin down Dr Patrick Bouic, Extraordinary Professor of Immunology and Chief Scientific Officer of Synexa Life Sciences to get his scientific take on COVID19 patients, like Melina, getting reinfected again after full recovery.
Common understanding of infections is that if you’ve contracted and recovered from it once, you are protected from subsequent reinfection. However, with COVID19, there seem to be people who get infected, get sick & show symptoms, recover and then over 1 month later, test positive for the virus again.
There are 3 possible scenarios happening on an immunological level that can explain why this might be happening:
SCENARIO 1: The Class of Antibodies:
We always think that antibodies are the only protective mechanism against reinfection and yes they are important but more important than general antibodies are the TYPE of antibody that you have. There are in fact different types of antibodies!
The first time you come into contact with COVID19, you develop antibodies of the IgM class - the primary antibody, thereafter (about 3-4 days), your body then starts to produce IgG antibodies, which are a lot more protective. However, the most protective are the IgA class of antibodies, which protect your mucosal surfaces ie: mucus membranes & saliva and lungs.
What we propose is happening is that some patients mount an immune response the first time the get infected but do not form enough antibodies of the IgA class, which means that they risk reinfection because there are not enough of these antibodies to bind and protect them from attack of a subsequent infection.
SCENARIO 2: The Level of Antibodies:
Antibody levels formed are directly proportionate to the severity of the infection. Therefore, someone with a mild infection might not produce enough antibodies to defend themselves against a possible addition exposure to the virus and resulting infection.
In addition, with other viruses, we usually keep the antibodies we’ve formed for quite a while but with COVID19, it seems to depend which antibodies you form along with the fact that COVID19 antibodies seems to fade away quicker. Therefore, it depends whether you still have enough antibody in your system to fight off the virus a 2nd time.
SCENARIO 3: The Virus:
A new or another infection could be caused by a mutation of the virus and the body doesn’t have the antibodies for this different virus.
There are so many unanswered questions with the Coronavirus but if we’re just looking at antibodies, it has to do with 1) the type of antibody, 2) the level of antibody and 3) whether the second infection is of the same (or similar enough) strain as the first.
However, there is another aspect to immunity against potential reinfection, which is the immune mechanism known as immunological memory and the T-cells.
T-Cells & a Vaccine:
The T-cells are the cellular response to the virus, not just the antibody immune response.
When a virus enters the body, it is taken up by dendritic cells that present the virus’s information to the T-cells. The T-cells then send a signal to B-cells that are responsible for making the antibodies to defend the body against the incoming virus. The T-cells keep this reactivity and the recipe for the antibodies, known as immunological memory, indefinitely, whereas antibodies dwindle as we’re seeing clearly with COVID19.
This T-cell response and immunological memory is essentially the aim of the Coronavirus vaccine!
We are going to be living with this virus for a very long time. There is an understandable fear around the virus because it is relatively new and unknown. However, the bulk of the population get over it. Some have severe symptoms but most have a very mild symptoms.
We should all stick to the basic recommendations of wearing a mask, sanitising, staying home, social distancing and staying healthy.
What we can control right now is how we look after our bodies and support our immune system, which can be done through:
Plenty of rest
Dr Bouic is a phenomenal Immunological scientist based in Cape Town who we’ve had the pleasure of working with in addressing some of our gut issues alongside the research we’ve assisted with in his COVID19 antibody research.
For more info about Synexa Life Sciences, please visit their website.