With all this talk about viruses, one will eventually land on the topic of vaccines. There are a lot of questions regarding the creation of a vaccine to help with the current pandemic and your friendly science major is here to help. People have their opinions on vaccines, but here, I’m going to just focus on the science behind them.
What is a vaccine?
A vaccine is a solution made to activate the body’s immune response to create specific antibodies to respond to the target a specific virus. There are several ways that this is done to make sure the people who receive the vaccine don’t get sick. The virus in the vaccine maybe killed or severely weakened, therefore making it incapable of actually infecting a person or only the protein shell of the virus is in the solution.
How do vaccines work?
As mentioned above, the vaccine doesn’t have the live virus in it, but it still initiates an immune response. To understand how that works, a quick lesson on how the human immune system works is needed. When the body finds something that doesn’t belong, it will start the first wave of defense that is a general response. It isn’t meant to be a long-term solution but just enough to keep the virus at bay for the second wave to respond. This is also why you might feel a little sick after your vaccine shot. If the body has seen the invader before, there are cells that recognize the pathogen and start to replicate and go after the pathogen to neutralize or kill it.
Vaccines show the body these pathogens without causing any of the negative effects of having a virus at full strength enter the body. The body creates lymphocytes, in the form of B cells and two subtypes of T cells. Both of these types of cells have receptor sites that recognize specific targets. The antibodies produced by the B cell when then be encoded for used if the same invader comes back.
Vaccines cause the body to create these cells so when the body is exposed to the live virus, the body already has a cellular memory of the virus protein coat so it can respond quicker and more efficiently to the pathogen.
How do you make a vaccine?
The virus has to be isolated and grown in the lab. This is where chicken eggs or lab-grown human cells come in handy. Once the virus is isolated, the virus is then killed or severely weakened, so the body will react to the protein shell of the virus without actually becoming infected. From there, some additives like aluminum salts (increase body’s response) and antibiotics (to prevent bacterial growth within the vaccine solution) along with preservatives are added.
Why does it take so long to make a working and accessible vaccine?
In the steps outlined above, it sounds like a vaccine should be easy and quick to make but it is more complicated than that. In some cases, the manufacturer of the vaccine might want to identify the protein structure of the virus to help understand how it could be treated. The process of creating the vaccine takes time. Especially since the next step could take even more time. The vaccine needs to get approved by the Food and Drug Administration. The FDA has very strict standards for the vaccines. Before human trials, there is the ingredient analysis, cellular trials and animal trails before it is even seen by a human patient. If all that goes well scientists need to figure out how to make the vaccine on a much larger scale so that it can be distributed to hospitals and pharmacies, which again takes time.
While scientists are working on making a vaccine as fast as possible, the earliest time a vaccine will be ready is likely to be 18 months. Unlike the flu, our bodies don’t have the cellular memory of the COVID-19 virus so our bodies are starting from scratch in initiating the second wave of the immune response, which takes time and means more time for the virus to multiply causing more cell death.
For now, the best options are to follow the procedures we have all already heard. Wash your hands, stay inside as much as possible and practice social distancing.