After getting a vaccination, your immune system is trained to recognise the virus and produce antibodies which attack the virus and remain in our bodies. In doing so, the immune system will be able to recognise the virus in the event of an infection and fight off the virus before it causes any symptoms.
Pfizer-BioNTech/ Comirnaty and Moderna are messenger RNA (mRNA) vaccines, while the Sinovac vaccine uses an inactivated vaccine technology.
- mRNA vaccines contain material from the COVID-19 virus that instructs our cells to produce a protein that is unique to the virus. After our cells make copies of the protein, they destroy the genetic material from the vaccine. Our bodies recognise that the protein should not be present and work to produce antibodies to attack the virus.
Inactivated vaccine technology uses weakened or inactive viral particles to stimulate our body to produce antibodies that will help neutralise the COVID-19 virus. The vaccine employs a modified delivery virus (that usually causes symptoms such as the common cold) to introduce SARS-CoV-2 viral proteins to the immune system, which then mounts a defense against it. The delivery virus has been attenuated or modified so you won’t develop the common cold when administered with this vaccine.
Some vaccines require multiple doses, with the doses given weeks or months apart. This allows us to produce longer-lasting antibodies and develop memory cells, so that our bodies and immune systems will be able to quickly fight the virus if we are exposed to it again.
Read more about how vaccines work.
References: gov.sg, World Health Organisation