Vaccine discovery

Why is it so difficult to discover a vaccine for COVID-19? 🦠 In order to induce protection against viral infections, a cytotoxic response is required. A specific type of circulating lymphocytes, the CD8 T cell population, is able to kill to viral infected cells. Another type of immune cells is needed, the antigen-presenting cell. which physically presents a specific antigen to CD8 T cells. This process involves a key complex, called MHC. In order to develop vaccines against viruses, an effective antigenic peptide to induce a strong cytotoxic response has to be identified. Immunologists commonly use MHC-binding predicting tools to screen for suitable targets. The main bottleneck in the development of COVID-19 vaccines relies on the fact that these predicting tools strictly depend on the MHC variants among individuals and show non-overlapping candidate antigens. In order to produce a vaccine, the antigenic peptide must be ideally shared by all individuals. Thus, the number of common peptides which might be exploited to design a vaccine becomes quite low and this renders the development of a suitable vaccine extremely challenging. A recent study provided 174 candidate epitopes which will be tested in the upcoming days. #covid_19#covid#ncov2019#immunology#vaccine#medicine#news#updates#science#health#molecularbiology#lymphocytes#biology