There are different types of COVID-19 vaccine including mRNA and viral vector vaccine. Pfizer, Moderna are examples of mRNA COVID-19 vaccines. On the other hand, Johnson & Johnson’s Janssen and Oxford–AstraZeneca are examples of viral vector COVID-19 vaccines.
Based on United States Centers for Disease Control and Prevention (CDC), viral vector vaccines use a modified version of a different virus, which is the vector to deliver important instructions to our cells. The vector is harmless and does not cause COVID-19. It contains the gene that encodes COVID-19 spike protein. After the vector enters the body cell, it uses the cell’s machinery to produce spike proteins, which can induce immune responses.
mRNA vaccines are a new type of vaccine. Once the mRNA is inside the body cells, the cells use them to make a protein piece, which is the spike protein. After the spike protein is produced, the immune response is triggered. Finally, our bodies have learned how to fight against the infection.
In short, both types of vaccines can give protection to us against COVID-19. They also do not affect or interact with our DNA. CDC does not recommend one vaccine over another as all authorized vaccines are safe and effective. Therefore we should get vaccinated regardless of the brand in order to generate immunity against the virus and to interrupt the spread of disease.