How Vaccines Work

And What That Means for COVID-19

Image by Angelo Esslinger from Pixabay

The immune system in a nutshell

When a pathogen (e.g. a virus, bacterium, or fungus) enters the body, the immune system kicks into gear. The first part of the response is non-specific, meaning it doesn’t depend on what the particular invader is.

Types of vaccines

There are two broad types of vaccines. Live attenuated vaccines contain a form of the virus that’s able to replicate, but it’s been weakened so that it doesn’t cause illness. However, in people who are immunocompromised, these usually aren’t a good idea, because people can actually get sick, although not as sick as if they were exposed to the non-weakened virus. The measles-mumps-rubella (MMR) vaccine is an example of this type of vaccine.

Components of a vaccine

Besides the actual weakened or inactivated virus, several other components are required. It’s crucial that the immune system mount enough of a response to the vaccine to achieve sufficient antibody titers to maintain immunity; otherwise, it’s all just a waste of time. Therefore, various agents, including aluminum, may be included to enhance the immune response. There are also preservatives, antibiotics to prevent contamination during manufacturing, agents to inactivate the virus and any protein toxins, and pH buffers. While some items on the ingredient list may sound scary, the amount in which they’re present is extremely small.

Booster shots

Typically, a single dose of a vaccine doesn’t generate enough of an immune response to give long-term protection When you get the first dose, the body tends to produce mostly IgM-type antibodies, which don’t stick around that long. With subsequent doses, the body produces more IgG-type antibodies, which give more lasting protection. Booster shots give your body the opportunity to produce sufficient IgG antibodies to be fully protected.

What this means for COVID-19

While there’s a lot that isn’t known about COVID-19, the principles of how vaccines work and how the immune system works are still there.

It’s a problem, though, when people who don’t have any of this background knowledge think their guess is as good as anything the scientists are doing, and misinformation starts flying around everywhere.

There are lots of different labs around the world working on coming up with a vaccine that works and is safe. Whether the first past the pose vaccine will involve weakened or inactivated virus, how it will be grown, and the number of doses that will be required, all remains to be seen. But all that baseline knowledge about vaccine development is still there.

Mental health blogger | Former MH nurse | Living with depression | Author of 3 books, latest is Managing the Depression Puzzle |