COVID-19: aspectos históricos e epidemiológicos na economia mundial e as vacinas em fase de teste no Brasil

Abstract

Coronavirus disease-2019 (COVID-19), a zoonosis resulting from infection by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), continues to end lives. Despite the numerous studies carried out around the world, the information regarding the virus and the disease are inconclusive. There is no curative medication or vaccine available universally, so far. Under these circumstances, the aim of this research was to develop a literature review, covering the historical and epidemiological aspects of the disease, the viral cycle and pathogenesis of SARS-CoV-2, the development of vaccines, the protective measures adopted and the impact of COVID-19 in the world economy. The review was based on scientific publications and government platforms National Center for Biotechnology, National Institutes of Health, Centers for Disease Control and Prevention, World and Health Organization and Brazil, between 2003 and 2021. The research revealed that Coronaviruses represent a serious threat to global health, as previously evidenced by the Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) and, currently, SARS-CoV-2. COVID-19 emerged in December 2019, in China, and since then there has been a significant increase in the number of cases worldwide, causing the World Health Organization to declare it a pandemic, the effects of which have been collapsing the system and triggering a negative impact on the world economy. The transmission of COVID-19 occurs mainly through the airways, followed by binding of the SARS-CoV-2 spike protein to the human Angiotensin-Converting Enzyme (host receptor), with consequent viral fusion and establishment of infection. As the symptoms of COVID-19 are nonspecific, ranging from oligo-symptomatic to Acute Respiratory Discomfort Syndrome and / or Systemic Syndrome, the definitive diagnosis is obtained by molecular tests (detecting viral genetic material) and immunological tests (detecting host antibodies). Once the infection is confirmed, the treatment is symptomatic, aiming at easing the patient's suffering and, in critical cases, maintaining the functions of his vital organs. Due to absence of curative medication, the development and availability of vaccines can be decisive for to deal with the pandemic. Currently, more than 150 vaccines have been developed using traditional platforms (weakened or killed virus vaccines) and new generation (Deoxyribonucleic Acid vaccines; Ribonucleic Acid; viral protein; viral vector - human adenovirus or chimpanzee adenovirus) in an unprecedented short time. Among the platforms, it is worth highlighting the chimpanzee adenovirus platform, known for having a high degree of safety and immunogenicity in combating several infections, including infection by MERS-CoV, as demonstrated by the ChAdOx1-MERS vaccine. Immediately after the release of the SARS-CoV-2 genome, the ChAdOx1-MERS platform was adapted for the development of the ChAdOx1-nCoV-19 vaccine (against SARS-CoV-2), a safe and effective immunizer. Therefore, it is possible to conclude that knowledge about other Coronaviruses has been contributing to the development of vaccines against COVID-19, and that the capacity of the health system, the cooperation of the population and government intervention, are essential to face the pandemic, until there is more knowledge about the virus and availability of vaccines worldwide.