Given the danger the novel coronavirus poses, the race to produce an effective vaccine is on.
How COVID-19 vaccines work
Different kinds of COVID-19 vaccines offer varying levels of protection. However, each of them helps our body develop immunity against the novel coronavirus. Irrespective of the type of vaccine shot you receive, the body is left with a supply of memory B-lymphocytes (defensive white blood cells that attack remnants of the virus) and T-lymphocytes (another type of defensive white blood cells that attack the already-infected cells in the body) that will remember how to fight against the virus in the future. It takes a few weeks for the body to generate T-lymphocytes and B-lymphocytes after vaccination.
Types of vaccines
Several COVID-19 vaccines are in development, out of which two (the Pfizer-BioNTech vaccine and the Moderna vaccine) were authorized for emergency use in the US. There are currently three types of COVID-19 vaccines in clinical trials in the US, which are:
- Protein subunit vaccines
These vaccines contain harmless protein pieces of the novel coronavirus instead of the whole germ. Once vaccinated, the immune system recognizes that the proteins are foreign material and starts producing T-lymphocytes and antibodies that help fight off the virus if we’re ever infected.
- Vector vaccines
These vaccines carry a weakened form of a live virus that’s different from the novel coronavirus. The weakened version contains genetic material from the virus that causes COVID-19, and this is called a viral vector. Once the viral vector enters our cells, it prompts the cells to make a protein unique to the novel coronavirus. Our cells then make copies of this protein, following which our bodies produce memory T-lymphocytes and B-lymphocytes.
- mRNA vaccines
mRNA vaccines contain material from the novel coronavirus that instructs our cells to make a harmless protein unique to the virus. After our cells produce copies of the protein, they destroy the genetic material from the vaccine. Our bodies then recognize that the protein is foreign and generate memory B-lymphocytes and T-lymphocytes. The Pfizer-BioNTech vaccine and the Moderna vaccine are both mRNA vaccines.
Vaccines seem to be our best chance at containing the COVID-19 pandemic.