Currently there are about 165 different vaccines for COVID-19 being developed around the world. The main types of vaccines include vector, inactivated, nucleic acid-based (DNA and mRNA) and recombinant protein-based vaccines.
Russian adenovirus vector-based vaccine was registered by the Russian Ministry of Health on August 11, 2020 and became the first registered COVID-19 vaccine on the market.
HOW ADENOVIRAL VECTOR-BASED VACCINES WORK
“Vectors” are vehicles, which can induce a genetic material from another virus into a cell. The gene from adenovirus, which causes the infection, is removed while a gene with the code of a protein from another virus spike is inserted. This inserted element is safe for the body but still helps the immune system to react and produce antibodies, which protect us from the infection.
The technological platform of adenovirus-based vectors makes it easier and faster to create new vaccines through modifying the initial carrier vector with genetic material from new emerging viruses that helps to create new vaccines in relatively short time. Such vaccines provoke a strong response from a human immune system.
Human adenoviruses are considered as some of the easiest to engineer in this way and therefore they have become very popular as vectors.
Source : Russia Sputnik V (https://sputnikvaccine.com)