ABSTRACT
In the early seventeenth century, smallpox was one of the most fearsome communicable diseases in the world. Lady Mary Montagu noted that the disease could be prevented by introducing liquid extracted from smallpox scabs from an infected patient into the skin of healthy individuals. This process, known as “variolation” was used in England and in USA until the first investigations by the English physician Edward Jenner appeared. Jenner created the vaccine for an animal poxvirus from the pustule formed by the vaccinia virus in the teats of cows, where the technique was essentially based on the idea that a virulent agent for animals could be attenuated in humans. In 1885, Louis Pasteur, through a fixed virus which was obtained by successive passages in the nervous tissue of rabbits with the dissecting action of potassium hydroxide, developed the vaccine against rabies, in which similar procedures were adopted in the development of several vaccines of live attenuated viruses. Already in the 1940s, a revolution occurred with the discovery that cells could be cultured in vitro and used as substrates for viral growth. Oral polio vaccine and vaccines against measles, rubella, mumps and chickenpox were made possible by selecting clones by passage in in vitro cell culture. Some RNA virus have segmented genomes that can be manipulated. Co-cultivation of two virus in cell culture with clone selection by plaque formation allows the isolation of virus with segments from both. This regrouping planned to create three main vaccines: live and inactivated influenza as well as one of two rotavirus vaccines. Another discovery in the late nineteenth century was that immunogenicity could be maintained as the substance contained in those killed by heat or chemical treatment. This type of inactivation was first applied to pathogens of typhoid fever, plague and cholera bacilli. In the twentieth century, chemical inactivation was also applied to a virus. The influenza vaccine was the first successful inactivated virus vaccine, developed against Polio and Hepatitis A. Besides, several vaccines consist of partially or fully purified proteins. Most of the inactivated flu vaccines used are created by growing the virus in embryonated eggs and then breaking down the entire virus with detergents. The viral hemagglutinin protein is purified to serve as the vaccine antigen, although other influenza virus components may be part of the final product. Early in the history of bacteriology, morphological studies and chemical analyzes showed that many pathogens were surrounded by a polysaccharide capsule and that antibodies against the capsule could promote phagocytosis. The first use of this information to create a vaccine was the development of the meningococcal polysaccharide vaccine. After years of study and development in bacterology, the scientific community faced the Covid-19 pandemic in 2020, marked by the race against time in the invention of effective vaccines against the SARS-CoV-2 virus. After all, most of vaccines take more than a decade to be formulated and, in the case of the vaccine against the new coronavirus, in less than a year, at least 34 candidate vaccines appeared in clinical analysis. New vaccine production techniques using DNA and RNA recombination techniques are being implemented in this race. In Brazil, the most widely distributed vaccines approved by Anvisa are AstraZeneca, CoronaVac and Pfizer-BioNTech. The AstraZeneca/Oxford vaccine is composed of a non-replicating viral vector, which consists of a defective chipamzee virus (adenovirus), with a segment of the SARS-CoV-2 genome, responsible for producing the structure present on the viral surface (protein S), being recognized by human cells, triggering an immune response against Coronavirus. The CoronaVac vaccine is composed by the inactivated SARS-CoV-2 virus, along with its complete structure. It is unable to multiply, although it can stimulate the response to produce antibodies. The Pfizer-BioNTech vaccine, on the other hand, consists of a formulated lipid nanoparticle of nucleoside-modified mRNA that encodes the pre-fusion peak glycoprotein of SARS-CoV-2. Despite the small amount of dose applications in Brazil, the Janssen vaccine has recently started its distribution in the country. This is the only vaccine, so far, with a single dose application. It is an adenovirus 26 (Ad26) vector vaccine that contains in its interior genetic material of the S protein contained in the surface spikes of SARS-CoV-2, and that stimulates, after application, the cellular responses of T CD4 + and T CD8 + antibodies. Here, we propose a detailed review of the entire history of vaccination, from Smallpox to Covid-19. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.