New evidence is emerging about the extended protection from COVID-19 we get through boosters (it’s not just about antibodies!).
University Health Chief Medical Officer Dr. Bryan Alsip talks about how our complex and mysterious immune system works, harnessing vaccines and boosters to fight future infection threats. He also provides a BA.2 update and a discussion of the latest CDC masking guidelines.
What are some reasons people may not be getting their COVID-19 booster?
We’ve got a lot of individuals who are fully vaccinated, which means they’ve had their first two doses of one of the mRNA vaccines or a single dose of the Jansen vaccine. They probably feel there’s some amount of protection with that.
There’s certainly no lack of opportunities to get a booster, but we’ve seen a lower percentage of uptake among boosters even for those who were very eager to get the first primary series. Even among health care workers, it’s not as high as we’d like it to be.
So in some cases there is perhaps a misunderstanding of the value of what boosters are and how they can help, and some people may not feel like they need an extra shot because they’ve already had a full series of the COVID vaccine.
If my antibody count has dropped, does that mean my immunity has waned?
Possibly. Immunity as measured by our antibody level is really only one aspect of our immune system. It’s actually a very complex system and there are a lot of parts to it.
Antibodies are one part because they are made by our white blood cells and they attach to viruses or bacteria that invade our bodies. It enables them to be destroyed or prevented from replicating.
But we also have other parts of our immune system that are working and are harder to measure. Your antibodies alone are only one measurement of how well your immune system is working.
How does a booster increase protection? Does it just give us more antibodies?
A booster does a couple of things. It helps remind our immune system of the pathogen we’re trying to protect against, and that often stimulates more antibodies. It also helps our immune system work better. We’ve found that boosters oftentimes will help our immune system recognize pathogens more quickly.
So not only do you have more antibodies in terms of overall defense to protect against that pathogen, but it probably recognizes it more quickly, and that’s another way to boost our immunity and our protection.
Besides antibodies, what are some other parts of our immune system?
Our immune system is complex. There are several parts, but one of the big parts of our immune system is what our white blood cells do. So we have red blood cells and white blood cells. White blood cells fight infection, and within that group we also have B cells and T cells.
B cells are primarily responsible for creating antibodies that we hear a lot about. They attach to bacteria or a virus and that either presents it to a cell that will destroy it or render it less likely to infect our own cells.
The T cells come in a couple of categories. The helper T cells work to make B cells better. Killer T cells go after our own cells that are infected with those viruses or bacteria so they can’t spread or cause illness.