ABSTRACT
BACKGROUND: The arrival of COVID-19 in Brazil and the accelerated process of dissemination/contamination added to the evolution of the clinical picture of the disease, and the saturation of the capacity of health services, creating new challenges for researchers, governments, and professionals involved in the occupational health area. OBJECTIVE: This article aims to systematize and synthesize the proposals adopted by the legislation and by the Brazilian State, with a focus on worker protection and guaranteeing a safe work environment for the performance of their professional activities. METHODS: This is qualitative bibliographical research of the narrative literature review type, developed from October 2020 to June 2021 in legislation databases using the strategy: "COVID-19" AND "coronavirus/coronavirus" AND "worker health" on official Brazilian government websites. RESULTS: The lack of an emergency plan for efficient actions to respond to the epidemic caused and is still causing the daily deaths of workers. CONCLUSION: There is a need to guarantee the effectiveness of national and international policies and norms that have been neglected by the Brazilian government.
ABSTRACT
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19), primarily infects cells at mucosal surfaces. Serum neutralizing antibody responses are variable and generally low in individuals that suffer mild forms of COVID-19. Although potent immunoglobulin G (IgG) antibodies can neutralize the virus, less is known about secretory antibodies such as IgA that might affect the initial viral spread and transmissibility from the mucosa. Here, we characterize the IgA response to SARS-CoV-2 in a cohort of 149 convalescent individuals after diagnosis with COVID-19. IgA responses in plasma generally correlated with IgG responses. Furthermore, clones of IgM-, IgG-, and IgA-producing B cells were derived from common progenitor cells. Plasma IgA monomers specific to SARS-CoV-2 proteins were demonstrated to be twofold less potent than IgG equivalents. However, IgA dimers, the primary form of antibody in the nasopharynx, were, on average, 15 times more potent than IgA monomers against the same target. Thus, dimeric IgA responses may be particularly valuable for protection against SARS-CoV-2 and for vaccine efficacy.
Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19/diagnosis , Immunoglobulin A/blood , SARS-CoV-2/immunology , Animals , Biomarkers/blood , COVID-19/blood , COVID-19/immunology , COVID-19/virology , Cell Line, Tumor , Chlorocebus aethiops , Convalescence , HEK293 Cells , Host-Pathogen Interactions , Humans , Protein Multimerization , Vero CellsABSTRACT
During the coronavirus disease-2019 (COVID-19) pandemic, severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) has led to the infection of millions of people and has claimed hundreds of thousands of lives. The entry of the virus into cells depends on the receptor-binding domain (RBD) of the spike (S) protein of SARS-CoV-2. Although there is currently no vaccine, it is likely that antibodies will be essential for protection. However, little is known about the human antibody response to SARS-CoV-21-5. Here we report on 149 COVID-19-convalescent individuals. Plasma samples collected an average of 39 days after the onset of symptoms had variable half-maximal pseudovirus neutralizing titres; titres were less than 50 in 33% of samples, below 1,000 in 79% of samples and only 1% of samples had titres above 5,000. Antibody sequencing revealed the expansion of clones of RBD-specific memory B cells that expressed closely related antibodies in different individuals. Despite low plasma titres, antibodies to three distinct epitopes on the RBD neutralized the virus with half-maximal inhibitory concentrations (IC50 values) as low as 2 ng ml-1. In conclusion, most convalescent plasma samples obtained from individuals who recover from COVID-19 do not contain high levels of neutralizing activity. Nevertheless, rare but recurring RBD-specific antibodies with potent antiviral activity were found in all individuals tested, suggesting that a vaccine designed to elicit such antibodies could be broadly effective.