Public Health Q&A: Antibodies, Reinfection, and the COVID-19 Vaccine
We’re keeping the public health Q&A going for the remainder of the year. We’ve received a few great questions about immunology and virology as they relate to COVID-19. Hopefully, these answers help those of you struggling with the disease or recovering from it and you are unsure of what happens next.
We received a lot of background information related to these questions. For the sake of protecting the privacy of people who ask, we are only divulging that these questions were asked by someone who tested positive for SARS-CoV-2, the virus that causes the disease COVID-19.
1) Because I’ve already had the virus, does this mean I now have the antibodies to fight the virus? (Note: This answer was framed in a way to be digestible to people who are not expert scientists, medical professionals, or public health professionals. It in no way encompasses the breadth and depth of immunology and virology that it could.)
a. This is a great question and a perfect time to succinctly explain how antibodies work. An antibody is a large, Y-shaped protein (also called an immunoglobulin) that our immune system uses to neutralize or “fight” a foreign pathogen such as SARS-CoV-2. The fork of the Y contains a highly variable region that allows our immune system to customize its response to any number of foreign pathogens. Because of this unique way to customize their response to foreign pathogens, antibodies (produced inside white blood cells or b cells) can bind specifically to different antigens or “chemical signatures” on the surfaces of different foreign pathogens and either destroy those antigens directly, or make it easier for white blood cells to destroy them. Our bodies may develop antibodies after being infected with a pathogen (barring there is no active autoimmune disorder present).
b. Some antibodies may develop and stay in the body for years (memory B cells). What we know, from research, regarding the development of antibodies from having COVID-19 is a mixed bag. Immune responses seem to differ. Some studies have shown that antibodies develop and can be detected in the blood for weeks or a few months. Others have shown that some patients don’t develop them at all. Quite simply, it is very difficult to tell if your one exposure to an infection with SARS-CoV-2 will give you life-long antibodies. We just don’t know enough about the science of this disease to give you a better outlook.
2) If I do have antibodies to fight the virus, and I am exposed to someone who has it, would I develop symptoms?
a. Short answer – we don’t know. So, continue to take the necessary precautions. Practice social and physical distancing whenever possible. Wear a mask when in public. Wash your hands thoroughly and frequently. Do not touch your face unless you have literally JUST thoroughly washed your hands. Stay away from crowded places. Don’t gather in large groups. Be safe.
3) Will I need to get the vaccine?
a. Yes. When a safe, efficacious vaccine is made available and accessible to all, you will need to get the vaccine.
While we know the answers to question #1 are not definite, we hope it sheds light on how antibodies work, in general, and how they work for COVID-19.
See you next week!
Helpful Links:
Mayo-Clinic: COVID-19 Antibody Testing