Vaccines are placed in different categories depending on how they are made and how they act.

mRNA Vaccines

mRNA vaccines against COVID-19 contain parts of the hereditary material of the SARS-CoV-2 virus in the form of messenger-RNA (mRNA for short). In this form, the vaccines carry the instructions for making the so-called spike protein, one of the proteins on the surface of the SARS-CoV-2 virus. When someone is vaccinated, the cells in their body start to make this protein which then stimulates an immune response. The mRNA in the vaccine does not enter the cell nucleus, the place where our own hereditary information is kept, and is quickly degraded by the body. It therefore has no effect on the person’s own genetic material.

Vector vaccine

Vector vaccines (from the Latin “vector” meaning “bearer”) are based on viruses that are harmless for humans (such as adenoviruses). These are genetically engineered so that their genetic material contains the building instructions for parts of another virus. In COVID-19 vaccines, the vector viruses contain the gene for making the spike protein on the surface of the SARS-CoV-2 virus. When someone is vaccinated, the cells in their body start to make this protein which then stimulates an immune response.

The adenoviruses used as vectors cannot reproduce in the body and are destroyed by the body within a short time.

Inactivated vaccines

Inactivated vaccines are also known as killed vaccines. They contain either killed pathogens or parts of pathogens. These are recognized by the immune system as foreign material and can thus stimulate an immune response without causing the illness itself.

As intensive research continues it is likely that more types of vaccine against COVID-19 will also become available. The World Health Organization (WHO) provides an overview of the current state of vaccine development.

Further information about COVID-19 vaccines is available on the Federal Health Ministry’s websites infektionsschutz.de and gesund.bund.de and from the Robert Koch Institute (RKI).

The Share to Care initiative provides evidence-based information about infection risks and the characteristics of the illness in vaccinated and unvaccinated people.

81