Vaccines past and future - a Brazilian perspective

Abstract

In this opinion article, I provide a brief history of vaccine development, commenting on the classic ways of obtaining vaccines using the infectious agent itself. Then, I address the issue of viral vaccines, their successes , difficulties, discussing the issue of viral serotypes. Bacterial vaccines and their relative success. I present our studies on Rheumatic Heart Disease and the development of an anti-streptococcal vaccine. Then, I discuss vaccine development platforms, especially with the successes achieved with non-replicating viral vector vaccines and, above all, the great success of mRNA vaccines. mRNA vaccines were only possible after the advances obtained with the replacement of nucleotides that reduced the action of innate immunity. Will all vaccines be made from mRNA in the future? Next, I address the issue of vaccine administration routes, whether subcutaneously, intradermally, intramuscularly or nasal instillation. I expose data from my laboratory on the development of an intranasal vaccine that induced a protective mucosal response, preventing infection , consequently the transmission of the SARS-CoV-2 virus. Then, I discuss which future vaccines could be developed beyond acute infectious diseases. Finally, I discuss the advantages of developing safe, effective, multiple-use vaccines and how to make them accessible to the world's population by promoting health equity.