Once you are vaccinated, your body develops immunity to COVID-19 that causes illness. There are different types of COVID-19 vaccines working in different ways but all of them offer protection.
For commonly available COVID-19 vaccines, you will need two shots (primary shots) of Pfizer-BioNTech and Moderna to be considered fully vaccinated while one shot (primary shot) is required for Johnson & Johnson.
A booster shot is recommended atleast six months after getting primary shots of Pfizer-BioNTech and Moderna and atleast two months after completing your Johnson & Johnson vaccine for people aged 18years and older whose protection has decreased over time.
It takes a few weeks after vaccination to provide protection against COVID-19.
The process of building immunity can cause symptoms such as fever after vaccination. The symptoms are normal and they are indicating that the body is building immunity.
There are mainly 3 categories of COVID-19 vaccines, namely; mRNA vaccines, Protein subunit vaccines and Vector vaccines. This is how they work;
mRNA vaccines e.g. Moderna and Pfizer have material from the virus that causes COVID-19. The material gives body cells instructions on how to make a harmless protein that is unique to the virus. After body cells have made copies of the protein, they destroy the genetic material from the vaccine. If one is infected in the future, our bodies are able to recognize that the protein should not be there and will remember how to fight the virus that causes COVID-19.
Vector vaccines e.g. AstraZeneca and Johnson & Johnson contain a modified version of a different virus than the one that causes COVID-19. The shell of the modified virus contains a material from the virus that causes COVID-19 called a viral vector. The genetic material gives cells instructions to make a protein that is distinctive to the virus that causes COVID-19 once the viral vector is inside our body cells. The body cells make copies of the protein using these instructions this in turn, enables our bodies to recall how to fight the virus if one is infected thereafter.
Protein subunit vaccines e.g. Novavax contain harmless proteins of the virus that causes COVID-19 instead of the entire germ. Our bodies recognize that the protein should not be there once we are vaccinated and will remember how to fight the virus that causes COVID-19 if we are infected thereafter.