We discuss the complex eco-social factors involved in the puzzle of the unexpected rapid viral spread in the ongoing Brazilian yellow fever (YF) outbreak, which has increased the reurbanisation risk of a disease without urban cases in Brazil since 1942. Indeed, this rapid spatial viral dissemination to the Southeast and South regions, now circulating in the Atlantic Forest fragments close to peri-urban areas of the main Brazilian megalopolises (São Paulo and Rio de Janeiro) has led to an exponential increase in the number of yellow fever cases. In less than 18 months, 1,833 confirmed cases and 578 deaths were recorded most of them reported in the Southeast region (99,9%). Large epizooties in monkeys and other non-human primates (NHPs) were communicated in the country with 732 YF virus (YFV) laboratory confirmed events only in the 2017/2018 monitoring period. We also discuss the peculiarities and similarities of the current outbreak when compared with previous great epidemics, examining several hypotheses to explain the recent unexpected acceleration of epizootic waves in the sylvatic cycle of the YFV together with the role of human, NHPs and mosquito mobility with respect to viral spread. We conclude that the most feasible hypothesis to explain this rapidity would be related to human behavior combined with ecological changes that promoted a significant increase in mosquito and NHP densities and their contacts with humans. We emphasize the urgent need for an adequate response to this outbreak such as extending immunisation coverage to the whole Brazilian population and developing novel strategies for immunisation of NHPs confined in selected reserve areas and zoos. Finally, we stress the urgent need to improve the quality of response in order to prevent future outbreaks and a catastrophic reurbanisation of the disease in Brazil and other South American countries. Continuous monitoring of YFV receptivity and vulnerability conditions with effective control of the urban vector Aedes aegypti and significant investments in YF vaccine production capacity and research and development for reduction of adverse effects are of the highest priority.

The immunogenicity and safety of a new recombinant hepatitis B vaccine from the Instituto Butantan (Butang®) were evaluated in a multicenter, double-blind, prospective equivalence study in three centers in Brazil. Engerix B® was the standard vaccine. A total of 3937 subjects were recruited and 2754 (70%) met all protocol criteria at the end of the study. All the subjects were considered healthy and denied having received hepatitis B vaccine before the study. Study subjects who adhered to the protocol were newborn infants (566), children 1 to 10 years old (484), adolescents from 11 to 19 years (740), adults from 20 to 30 years (568), and adults from 31 to 40 years (396). Vaccine was administered in three doses on the schedule 0, 1, and 6 months (newborn infants, adolescents, and adults) or 0, 1, and 7 months (children). Vaccine dose was intramuscular 10 µg (infants, children, and adolescents) or 20 µg (adults). Percent seroprotection (assumed when anti-HBs titers were > 10mIU/ml) and geometric mean titer (mIU/ml) were: newborn infants, 93.7% and 351.1 (Butang®) and 97.5% and 1530.6 (Engerix B®); children, 100% and 3600.0 (Butang®) and 97.7% and 2753.1 (Engerix B®); adolescents, 95.1% and 746.3 (Butang®) and 96% and 1284.3 (Engerix B®); adults 20-30 years old, 91.8% and 453.5 (Butang®) and 95.5% and 1369.0 (Engerix B®); and adults 31-40 years old, 79.8% and 122.7 (Butang®) and 92.4% and 686.2 (Engerix B®). There were no severe adverse events following either vaccine. The study concluded that Butang® was equivalent to Engerix B® in children, and less immunogenic but acceptable for use in newborn infants, adolescents, and young adults.

A grande maioria das polêmicas públicas relativas a hipotéticos malefícios provocados pelas vacinas é extensão de controvérsias e discussões que surgem no próprio meio médico. Exemplos são os malefícios do mercúrio contido em várias vacinas, como a tríplice viral (MMR), provocando doença inflamatória intestinal e autismo; a vacina contra hepatite B e esclerose múltipla; o vírus SV40 em vacinas contra poliomielite e câncer; a transcriptase reversa em células de embrião de pinto e riscos de infecção por retrovírus; vacinas como causa de asma, diabetes insulino-dependente. Em algumas situações houve nítido prejuízo para a saúde da população, como aconteceu na Inglaterra após noticiários alarmantes sobre os riscos da vacina tríplice DTP na década de 1970 e, mais recentemente, com a vacina tríplice viral, contra sarampo, caxumba e rubéola, também na Inglaterra, e a vacina contra hepatite B, na França. Além disso, grupos ativistas contrários à vacina veiculam notícias alarmantes através dos meios de comunicação, especialmente pela Internet. Beneficiam-se dessa situação pessoas e advogados que, com ou sem fundamento científico para as suas alegações, buscam indenizações milionárias, o que tem causado malefícios para a população, principalmente em países como os Estados Unidos, pelo aumento no custo das vacinas, para fazer frente aos processos judiciais, e pela desistência de produção por várias empresas, contribuindo para crises de disponibilidade das vacinas. O Programa Nacional de Imunizações do Brasil tem tido êxito em lidar com os aspectos públicos dos eventos adversos, através da capacitação dos profissionais de saúde que atuam no setor, tanto nos aspectos técnicos como na comunicação social.

Most public debate surrounding the hypothetical adverse effects of vaccines is an extension of the polemics, controversies, and discussions that have arisen within the medical field itself. Examples include the adverse effects of the mercury contained in a number of vaccines, such as the one against measles-mumps-rubella (MMR), which can cause inflammatory bowel disease and autism; the link between the hepatitis B vaccine and multiple sclerosis; the polio vaccine, the SV40 virus, and cancer; reverse transcriptase in chicken embryo cells and the risk of infection by retrovirus; and vaccines as a cause of asthma and insulin-dependent diabetes. In some cases, the public health has clearly been harmed-in England, for instance, when alarming reports circulated about the risks of the DTP vaccine in the 1970s or, more recently, involving the MMR vaccine, likewise in England, and the vaccine against hepatitis B, in France. Groups of activists against vaccines have also spread alarming stories through the media, especially the internet. The ones who gain from this situation are the people and lawyers who sue for millions in damages, whether or not their allegations have any scientific basis. This has brought further problems for the public at large, especially in countries like the United States, with the cost of vaccines rising to cover the cost of lawsuits and with a number of companies halting their vaccine production, thus contributing to crises of vaccine availability. Brazil's National Immunization Program has been successful in dealing with the public aspects of adverse events by training the health professionals working in this sector, not just in technical aspects but also in social communication.

O governo federal, nos anos mais recentes, vem desenvolvendo importantes iniciativas no sentido de fortalecer o sistema de ciência, tecnologia e inovação (CT&I) e, conseqüentemente, de aumentar os resultados da inovação tecnológica em várias áreas importantes da economia do país. Essas iniciativas, no entanto, ainda são insuficientes para diminuir a enorme dependência de insumos e tecnologias vindas de países mais desenvolvidos. Apresenta-se neste trabalho a situação da vacinação, produção e desenvolvimento tecnológico de vacinas no mundo e no Brasil; também são feitas algumas reflexões sobre a complexidade da inovação tecnológica de vacinas e as diversas etapas do processo de desenvolvimento tecnológico requeridas para esse completo desenvolvimento. Descrevem-se as várias etapas envolvidas, com análise dos parâmetros e fatores integrantes em cada etapa, os requisitos técnicos de instalações e equipamentos, as normas de boas práticas de fabricação (BPF), a necessidade organizacional, de infra-estrutura e de gestão, o longo período e o alto custo demandados para essa atividade.

In very recent years, the federal government has launched important initiatives meant to strengthen science, technology, and innovation in Brazil and thus enhance the results of technological innovation in key areas of the country's economy. Yet these initiatives have not been enough to reduce Brazil's heavy dependence on goods and technology from more developed nations. The article describes the current state of vaccination, production, and technological development of vaccines both internationally and nationally. Some thoughts are also offered on the complexity of vaccine innovation and the various stages whose completion is essential to the whole process of technological development. An analysis is made of the parameters and factors involved in each stage; technical requirements for facilities and equipment; Good Manufacturing Practice guidelines; organizational, infrastructural, and managerial needs; and the lengthy time periods and high costs entailed in these activities.