Tuberculosis vaccine – Bacillus Calmette-Guérin (BCG), probably associated with a reduced number and/or severity of COVID-19 cases in certain countries, could assist future COVID-19 vaccine developments. Recent research conducted by a team of scientists from University of Houston has found that the tuberculosis vaccine BCG could prove to assist future vaccine development against COVID-19. The researchers reported that the cross reaction between the two illnesses might help explain what could be driving immunity brought on by the BCG vaccination. According to researchers, the protection against SARS-CoV-2 induced by BCG vaccination may be mediated by cross-reactive T cell lymphocytes, which recognize peptides displayed by class I Human Leukocyte Antigens (HLA-I) on the surface of infected cells. The study report, published in the journal Frontiers in Immunology, lead author Dinler Amaral Antunes, said that the research implemented a large-scale computational screening of over 13.5 million peptide pairs to identify potential targets with biochemical similarities between the two illnesses. The researchers expressed hopes that the development of peptide-based vaccines targeting coronaviruses and presenting cross-reactivity with existing pools of memory T cells would help complement the protection conferred by COVID-19 vaccines.