Each person seems to have a unique immune system. My colleagues and I discovered this immune diversity after finding antibodies in the blood of healthy and sick people. The discovery could help explain why, for example, COVID vaccines appear to be less effective for some people. At the same time, it indicates the possibility of identifying and recovering particularly effective antibodies from individuals and using them to cure others.
In our daily life, our body is confronted and attacked by many germs which use clever tricks to enter our body, in order to gain control. Fortunately, we have a powerful defense: our immune system.
With a functioning immune system, we can fight off most germs that continually and aggressively approach us. Part of our arsenal of weapons to neutralize invading germs is made up of protein molecules called antibodies. These antibodies are abundant in the blood, circulating throughout our body, forming the first line of defense when a new nasty germ appears.
Each different germ requires a different arsenal of weapons (antibodies) to fight them as effectively as possible. Fortunately, our bodies have provided us with a way to make millions, if not billions, of different antibodies, but they cannot all be made at the same time. Often, specific antibodies are made only in response to a particular germ.
If we get infected with bacteria, we start making antibodies to attack and kill these bacteria. If we are infected with the coronavirus, we start making antibodies to neutralize this virus. When they get infected with the flu virus, we make more of them again.
How many different antibodies are made at any given time and are therefore present in our blood, was not known. Many scientists have estimated it to be over several billion and therefore almost immeasurable. Using a few blood droplets and a technique called mass spectrometry, my colleagues and I were able to capture and measure the number of different antibodies in the blood and also assess the exact concentration of each one.
Although theoretically our body has the capacity to make thousands of billions of different antibodies, a first surprise came when we found that in the bloodstream of healthy and sick people, a few tens to hundreds of distinct antibodies were present. high concentrations.
By monitoring these profiles from a few droplets of blood, we were surprised for the second time when we noticed that the way the immune system reacts to germs varies greatly from person to person, the antibody profile of each person being unique. And the concentrations of these antibodies change in a unique way during illness or after vaccination. The results may explain why some people are more likely to get sick with the flu or COVID, or why they recover faster from certain illnesses than others.
Until now, scientists have considered it impossible to accurately map the very complex mixture of antibodies in the blood. But mass spectrometry separates substances based on their molecular makeup, and since each specific antibody has a distinct molecular makeup, we were able to use a refinement of the technique to measure all of the antibodies individually.
The method has been used to measure antibody profiles in around 100 people, including COVID patients and people vaccinated with different COVID vaccines. Not once have we encountered the same antibodies in two different people, even though they had received the same vaccine. It’s safe to say that everyone’s antibody profile is as unique as their fingerprint.
Even though the differences in antibodies are small, they greatly influence the course of a disease. If someone makes fewer antibodies against a certain germ, or only antibodies that are less effective at killing the germ, then a disease may strike harder or more times. On the other hand, if people produce antibodies which are excellent at neutralizing the germ, that antibody could be produced for therapeutic purposes and used to vaccinate or treat patients.
Our research creates opportunities to make optimal vaccines and drugs tailored to an individual’s immune system. By mapping a person’s antibody profile, you can track their body’s reaction to a vaccine or infection, or even drug treatment. This way you can also check whether the body is producing enough desired antibodies, for example those against the coronavirus. If they don’t produce enough, you may consider offering booster shots or antibodies that have worked for other people.