Vaccines that carry genetic code
For example: the adenoviral-based vaccines (produced by AstraZeneca and Janssen) and the mRNA vaccines (produced by Pfizer/BioNTech and Moderna)
Genetic or gene vaccines encode genetic information, which enables human cells to produce a viral antigen.
In the case of the 2021 vaccines, they induce the protein synthesis machinery of human cells to translate the spike protein of the viral capsid of SARS-CoV-2.
Upon its translation by the ribosomes, the spike protein gets processed by the Golgi apparatus and presented to the immune system in two forms: i) as an entire protein, displayed on the cellular membrane, which can be recognized by B cells and T-helper cells; or in the form of fragments loaded on the major histocompatibility complex I (MHC I), which presents the endogenous antigens to CD8+ T lymphocytes.
Genetic code is the set of rules used by living cells to translate information encoded within genetic material (DNA or RNA sequences of nucleotide triplets, or codons) into proteins. Translation is accomplished by the ribosome, which links proteinogenic amino acids in an order specified by messenger RNA (mRNA), using transfer RNA (tRNA) molecules to carry amino acids and to read the mRNA three nucleotides at a time. The genetic code is highly similar among all organisms and can be expressed in a simple table with 64 entries.