Primer on Covid-19 and Immunity
by Eugene Lou, MD
Jan 20, 2021
Covid-19 has disrupted lives around the world and led to a myriad of issues ranging from economic disaster to mental health tolls. Weekly there seems to be varying and sometimes contradictory messages from experts which further exacerbates the state of frustration and fear in our communities.
I would like to give a synopsis and brief explanation of the current state of knowledge which may give some clarity and peace of mind the community. My educational background was in genetics/molecular biology at the Massachusetts Institute of Technology. I worked on research projects and published with 3 Nobel Laureates in the field of the Human Genome Project at the Whitehead Institute. Immunology/Virology was an integral part of my studies and training. For the past 20+ years I have been an orthopedic surgeon in private practice who has also done voluntary teaching for residency programs.
A) Basics of the immune system – the main components of the immune system are the B cells and the T cells. B cells produce antibodies that act as the guard dogs of the body. T cells are the Terminator cells that destroy invaders such as viruses and bacteria. The B cells produce and replicate antibodies when they encounter foreign invaders. The “guard dog” antibodies will cling to the foreign invaders and slow them down, potentially rendering them impotent so the invaders cannot cause problems. The Terminator cells will recognize the clusters of guard dogs attached to the invaders and will ingest and destroy them. The Terminator cells can also recognize and destroy invaders in the absence of the guard dogs as well.
B) Antibody testing – the guard dogs can be measured on COVID antibody tests when they are circulating in numbers. Typically their presence is measured 3 days to 3 months after exposure to COVID. After 3 months their levels are not detectable but this does not mean they are gone! They are simply in storage or resting. Think of the antibodies as guard dogs barking at the mail man. You can hear and see them but they are quiet after the mail man leaves. This doesn’t mean they are gone – they’re just not barking at the window. We now know the B cells that produce the guard dogs /antibodies to COVID elevate to a high level after exposure and remain elevated for probably 10 years or more. Therefore antibody activity can be mobilized at any time
C) T cell testing – likewise, COVID specific T cells increase and remain elevated after COVID exposure and likely will remain available for 10 years or more
D) Vaccines – the current vaccines such as Pfizer and Moderna introduce a man-made m-RNA into the body which then instructs our own cells to produce pieces of the COVID virus that will trigger our immune systems to train to kill. In the past, vaccines have used dead or synthetic viruses to train our immune system. The most accurate vaccine you can train your immune system to recognize would be the actual virus itself. When searching for a lost person or pet we typically use photos of the actual lost person/pet, as it is more accurate that a sketch or drawing.
E) Inherent immunity – we have testing blood donated between 2015-2018 and found that up to 40% of this blood has some intrinsic immune response vs COVID-19. Blood donated before the COVID pandemic has some immune response vs COVID!! How can this be? COVID is a part of the coronavirus family which includes the common cold. Think of your immune system as a car enthusiast. Someone brings a BMW from 2030 to present day. The car enthusiast can recognize some traits and patterns in the styling that would allow the enthusiast to deduct that future car as being a BMW.
F) Immunity passport – There has been talk of being able to give people an immunity passport recognizing that they are immune to COVID and non infectious to permit unrestricted travel, etc. This will soon be available through testing of COVID specific B and T cell levels. This immunity passport testing will let us know that our immune systems are ready to prevent COVID infection whether from inherent immunity, immunity after COVID exposure, or immunity after vaccination. It will also allow us to determine if any primary or repeat vaccination is necessary
G) Herd Immunity – When a significant portion of the population becomes immune to COVID the rate of transmission will drop precipitously and the virus will burn out. The virus would be like a tired door to door salesman unable to gain entry to non-responsive households, then fading away because it can no longer recharge inside these households and replicate itself.
In summary we soon will be able to effectively manage and navigate the needs of the community to achieve “herd immunity.” New immunity testing will allow us to determine who actually would benefit from immunization and who doesn’t need it. This will be very important in allowing society to resume normal social functioning.
Eugene Lou, MD